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Climate Archives in Coastal Waters of Southern Africa – Cruise No. M123 – February 03 – February 27, 2016 - Walvis Bay (Namibia) – Cape Town (Rep. of South Africa). METEOR-Berichte, M123, 50 pp.

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This research cruise M123 was directly connected to the collaborative research project RAiN (Regional Archives for Integrated iNvestigations) which is funded by the Ministry of Education and Research (BMBF) in the framework of the SPACES program (Science Partnerships for the Assessment of Complex Earth System Processes). The overreaching goal of this project is to expand the current state of knowledge on the drivers and dynamics of South African Late Quaternary climate change by directly comparing marine and terrestrial proxy-records. Whereas sufficient sample material for these analyses was retrieved from the western South African coast during former expeditions, suitable marine sediment cores with high resolution deposits were not available from the south and east coast of southern Africa until now. This was, in part, due to patchy records affected by the regional style of dominant sedimentation regimes along these shores, which are influenced primarily by the strong south-westward flowing Agulhas contour current which causes erosion and sediment redistribution processes rather than accumulation and preservation. As we suspected and now proved true, based on detailed information on surface sediment characteristics and recent geomorphological studies of the shelf and continental slope areas, both provided by the South African co-proponents and partners, we could find the smallscale Holocene sediment bodies with sufficient thickness and were able to retrieve long sediment cores in front of all major rivers along the coast of southern Africa up to the Limpopo River. Depending on sediment grain size and texture, sea floor samples were taken with gravity corer, vibrocorer, box corer and multicorer. Surface samples and sediment cores could be retrieved at 25 sites from water depth between 32 m and 3.059 m, with a total recovery length ofmore than 107 m. For the purpose of identifying the best locations for coring, the ship’s acoustic systems were used along more than 900 nm of profile lines. In addition to the sediment work, at six sites planktonic foraminifera could be sampled using a multinet. Beside the scientific goals of this expedition, a strong focus was placed on the training of young scientists and advanced students from Germany and South Africa.
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METEOR Berichte
Climate Archives in Coastal Waters of Southern Africa
Cruise No. M123
February 03February 27, 2016
Walvis Bay (Namibia) – Cape Town (Rep. of South Africa)
M. Zabel
Editorial Assistance:
DFG-Senatskommission für Ozeanographie
MARUM Zentrum für Marine Umweltwissenschaften der Universität Bremen
2017
M123
03. Febr. 27. Febr. 2016
The METEOR-Berichte are published at irregular intervals. They are working papers for people who
are occupied with the respective expedition and are intended as reports for the funding institutions.
The opinions expressed in the METEOR-Berichte are only those of the authors.
The METEOR expeditions are funded by the Deutsche Forschungsgemeinschaft (DFG) and the
Bundesministerium für Bildung und Forschung (BMBF).
Editor:
DFG-Senatskommission für Ozeanographie
c/o MARUM – Zentrum für Marine Umweltwissenschaften
Universität Bremen
Leobener Strasse
28359 Bremen
Author:
Dr. Matthias Zabel Telefon: +49-421-218 65103
Universität Bremen – MARUM Telefax: +49-421-218-9865103
Leobener Str. e-mail: mzabel@marum.de
D-28359 Bremen / Germany
Citation: M. Zabel (2017) Climate Archives in Coastal Waters of Southern Africa – Cruise No. M123
– February 03 – February 27, 2016 - Walvis Bay (Namibia) – Cape Town (Rep. of South Africa).
METEOR-Berichte, M123, 50 pp., DFG-Senatskommission für Ozeanographie,
DOI:10.2312/cr_m123
_________________________________________________________________________________
ISSN 2195-8475
Table of Contents
Page
1 Summary / Kurzfassung 1
2 Participants 2
3 Research Program and Narrative of the Cruise 3
4 Preliminary Results 5
4.1 Acoustic Surveys 5
4.2 Sediment sampling 10
4.3 Physical Properties 11
4.4 Mineralogy 21
4.5 Microfossils 25
4.6 Plankton Sampling 39
4.7 Sampling of Surface Water Suspended Material 41
4.8 Water Sampling 42
5 Ship’s Meteorological Station 43
6 Station List 45
7 Data and Sample Storage and Availability 46
8 Acknowledgments 46
9 References 47
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 1
1 Summary
This research cruise M123 was directly connected to the collaborative research project RAiN
(Regional Archives for Integrated iNvestigations) which is funded by the Ministry of Education
and Research (BMBF) in the framework of the SPACES program (Science Partnerships for the
Assessment of Complex Earth System Processes). The overreaching goal of this project is to
expand the current state of knowledge on the drivers and dynamics of South African Late
Quaternary climate change by directly comparing marine and terrestrial proxy-records. Whereas
sufficient sample material for these analyses was retrieved from the western South African coast
during former expeditions, suitable marine sediment cores with high resolution deposits were not
available from the south and east coast of southern Africa until now. This was, in part, due to
patchy records affected by the regional style of dominant sedimentation regimes along these
shores, which are influenced primarily by the strong south-westward flowing Agulhas contour
current which causes erosion and sediment redistribution processes rather than accumulation and
preservation. As we suspected and now proved true, based on detailed information on surface
sediment characteristics and recent geomorphological studies of the shelf and continental slope
areas, both provided by the South African co-proponents and partners, we could find the small-
scale Holocene sediment bodies with sufficient thickness and were able to retrieve long sediment
cores in front of all major rivers along the coast of southern Africa up to the Limpopo River.
Depending on sediment grain size and texture, sea floor samples were taken with gravity corer,
vibrocorer, box corer and multicorer. Surface samples and sediment cores could be retrieved at 25
sites from water depth between 32 m and 3.059 m, with a total recovery length of more than 107 m.
For the purpose of identifying the best locations for coring, the ship’s acoustic systems were used
along more than 900 nm of profile lines. In addition to the sediment work, at six sites planktonic
foraminifera could be sampled using a multinet. Beside the scientific goals of this expedition, a
strong focus was placed on the training of young scientists and advanced students from Germany
and South Africa.
Zusammenfassung
Die Expedition M123 stand im unmittelbaren Zusammenhang mit dem deutsch-südafrika-nischen
Forschungsverbundvorhaben RAiN (Regional Archives for Integrated iNvestigations), welches
durch das Bundesministerium für Bildung und Forschung (BMBF) finanziert wird und Teil des
SPACES-Programms (Science Partnerships for the Assessment of Complex Earth System
Processes) ist. Das übergeordnete, wissenschaftliche Ziel in RAiN ist die Erweiterung des
aktuellen Kenntnisstandes zur Steuerung und Dynamik der spätquartären Klimavariabilität im
südlichen Afrika. Der Schlüssel hierzu wird unter anderem in Vergleichen zwischen terrestrischen
und marinen Sedimentarchiven gesehen. Während es aufgrund vorheriger Expeditionen genügend
Probenmaterial für entsprechende Untersuchungen von der Westküste Südafrikas gibt, konnten
von der Süd- und Ostküste keine Sedimentkerne mit hinreichend zeitlich hochauflösenden
Ablagerungen gewonnen werden. Dies ist den regionalen Sedimentationsbedingungen
zuzuschreiben, die insbesondere küstennah durch den süd-westlich fließenden Agulhas-Strom
bestimmt werden, wodurch stark erosive Umlagerungsprozesse hervorgerufen werden. Wie von
uns erwartet und durch die Ergebnisse dieser Expedition bestätigt, lassen sich auf Basis neuerer
geomorphologischer Studien und vorhandener Informationen zu Verteilungsmustern von
2 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Oberflächensedimenten dennoch kleinräumige holozäne Sedimentkörper mit hinreichender
Mächtigkeit vor allen Flussmündungen des südlichen Afrika finden. Der Erfolg der Ausfahrt
M123 wurde maßgeblich durch die enge Zusammenarbeit mit den südafrikanischen Partnern bzw.
deren Zurverfügungstellung von Detailinformationen ermöglicht. Je nach Korngrößenspektrum
der Ablagerungen wurden zur Probennahme Schwerelot, Vibrolot, Großkastengreifer und/oder
Multicorer eingesetzt. Insgesamt konnten an 25 Lokationen Oberflächensedimente aus
Wassertiefen von 32–3.059 m gewonnen werden. Die Gesamtlänge der mit Loten gewonnen
Kerne beträgt 107 m. Um die bestmöglichen Lokationen zur Probennahme zu finden wurden die
akustischen Systeme des FS Meteor auf Profilfahrten von über 900 nm Länge eingesetzt. Zur
Beprobung planktischer Foraminiferen in der Wassersäule erfolgten ferner an sechs Stationen
erfolgreiche Einsätze eines Multischließnetzes. Neben der Verfolgung wissenschaftlicher Ziele lag
ein besonderer Fokus dieser Expedition auf der praktischen Ausbildung junger Wissenschaftler
und fortgeschrittener Studenten aus Deutschland und Südafrika.
2 Participants
Tab. 2.1 List of scientific party
Name Discipline Institution
Zabel, Matthias, PD Dr.
Sediment Geochemistry /
Chief Scientist (CS)
MARUM
Amberg, Sebastian
Student
MARUM
Andò, Sergio, Prof. Dr.
Sedimentology
UNIMIB
Bergh, Eugene, PhD-stud.
Student
UCT-Geo
Cawthra, Hayley, Dr.
Marine Geology
CG
Du Plesis, Nadia, PhD-stud.
Student
UCT-EGS
Eichenauer, Christian, Ing.
Documentation
(Freelancer)
Frederichs, Thomas, Dr.
Geophysics
GeoB
Frenzel, Peter, PD Dr.
Micropaleontology
FSUJ
Gander, Lukas
Student
FSUJ
Gilson, Dirk, Journalist
Documentation
(Freelancer)
Gomes, Megan
Student
UW
Green, Andrew, Prof. Dr.
Geomorphology; Co-CS
UKZN-Geo
Hahn, Annette, Dr.
Sediment Geochemistry
MARUM
Higgs, Caldin
Student
UW
Hinkeldey, Alexander
Student c
GeoB
Hoffmann, Daniel
Student
GeoB
Humphries, Marc, Dr.
Geochemistry
UW
Kossack, Michael
Student
MARUM
Maboya, Matjie Lilian
Student
UCT-EGS
Khumalo, Vamamusa
Student
UCT-Geo
Pillay, Talicia
Student
UKZN-Geo
Pretorius, Lauren
Student
UKZN-Geo
Rohleder, Christian, Met.
Meteorology
DWD
Siccha, Michael, Dr.
Micropaleontology
MARUM
Schade, Tobias, Tech.
Technology
MARUM
Schefuß, Enno, Dr.
Organic Geochemistry
MARUM
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 3
Stelzner, Martin, Tech.
Meteorology
DWD
Strachan, Kate, Dr.
Micropaleontology
UKZN-ES
Wiles, Errol, Dr.
Geomorphology
UKZN-Geo
Participating Institutions
CG
Council for Geosci., Geophys. Competency Marine Geosci.
Unit, 3 Oos Street, 7535 Bellville, South Africa
www.geoscience.
org.za
DWD
Deutscher Wetterdienst, Geschäftsfeld Seeschifffahrt,
Bernhard-Nocht-Str. 76, D 20359 Hamburg, Germany
www.dwd.de
GeoB
Dept. of Geosciences, Bremen University
Klagenfurter Str., D 28359 Bremen, Germany www.geo.uni-bremen.de
FSUJ
Friedrich-Schiller-Univ. Jena, Institute of Geosciences,
Burgweg 11, 07749 Jena, Germany
www.igw-ahg.
uni-jena.de
MARUM
Centre for Marine Environmental Sciences
Leobener Str., D 28359 Bremen, Germany
www.marum.de
UCT-EGS
University of Cape Town, Dept. of Environmental Geographical
Sci., 7701 Rondebosch / South Africa
www.egs.uct.ac.za
UCT-Geo
University of Cape Town, Dept. of Geological Sci.,
7701 Rondebosch / South Africa
www.geology.uct.
ac.za
UKZN-ES
University of KwaZulu-Natal, Environ. Sci. /
Phys. Geography, 4000 Westville / South Africa
www.ukzn.ac.za
UKZN-Geo
University of KwaZulu-Natal, Geology Mar. Geol.
Res. Unit, 4000 Westville / South Africa
www.ukzn.ac.za
UNIMIB
Univ. of Milano Bicocca, Dept. of Earth and Environ. Sci.,
Piazza della Scienza 4, 20126, Milano, Italy
www.geo.unimib.it
UW
Univ. of the Witwatersrand - Faculty of Science School of
Chemistry, Private Bag 3, 2050 PO WITS / South Africa
www.wits.ac.za/
chemistry
Fig. 2.1 Scientific party on M123
3. Research Program and Narrative of the Cruise
(M. Zabel)
Our research program concentrated on three main working areas along the south- and east-coasts
of southern Africa. On the south coast off Mossel Bay and on the east coast south of Durban, we
4 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
continued a first sampling campaign, which started successfully in December 2013 on R/V
METEOR expedition M102. The third area was the outer Maputo Bay, where we expected to find
deposits consisting of sediments from the Limpopo River catchment. From two former expeditions
(M63-1 and M75-3) seismic information exist, which have been published in the meantime and
now could be used to better understand the regional sediment distribution pathways and to identify
areas with high accumulation rates during the Late Quaternary. Due to the lack of detailed
information from the shelf areas, on both previous expeditions shallow water areas were not
searched for fine-grained deposits, which are a prerequisite for most investigations when the target
is to identify and decipher climate signals in terrigenous sediments. Instead, both cruises had
focused on the continental slope.
Fig. 3.1 Cruise trajectory and sampling sites.
The expedition started in the morning of February 3 from the harbor of Walvis Bay (Namibia).
Due to the very long transits (from Walvis Bay (Namibia) to the other side of the continent
(Mozambique) and back to Cape Town) and taking the current pattern into account, we decided to
start our pre-site surveys in Mozambican waters off the Limpopo River Mouth. On the 10-day-
transit one gravity core in the southern Cape Basin and a first set of surface sediments at four sites
on the narrow east coast shelf were taken. We had to learn that the patches of more muddy
sediments are very local and very restricted, that it takes some effort to identify them with the
PARASOUND system and that it is even more difficult to sample them. Although the grain sizes
spectrum of the minerals showed a great variety, heavy mineral assemblages could already be
assigned to different source areas. On February 12 we arrived at the first location in working area
1 (GeoB20607). During the next nearly five days nine successful gravity corer deployments
followed at 11 sites. On Tuesday, February 16, we left working area 1 and started to return. With
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 5
the strong Agulhas stream the vessel made rapid progress. At about 29,4°S, 31,5°E we found a
several meter thick package of muddy sediments north of the Tugela River mouth in about 32m
water depth. At this location we could retrieve three up to 8,26 m long sediment cores, a very
unusual procedure at a very unique site. According to the previous plan the work was carried out
successively in both other working areas. After 25 days with mostly very favorable weather
conditions the expeditions ended in the early morning of February 27 in the harbor of Cape Town.
4 Preliminary Results
4.1 Acoustic Surveys (Parasound and Multibeam)
(A. Green, H. Cawthra, A. Hinkeldey, M. Humphries, V. Khumalo, L. Pretorius,
K. Strachan & E. Wiles)
Continuous PARASOUND and multibeam bathymetric profiling was undertaken since entering
South African waters on the 5th February 2016. The primary aim of the hydroacoustic surveying
was to identify suitable fine-grained sediment deposits on the shelf and upper slope offshore the
main fluvial entry points to the south and west coasts of South Africa and southern Mozambique.
In addition to the newly collected data, existing local datasets were used as reference (e.g. the
past and ongoing work of South African marine geologists in RAiN), as well as a series of older
published marine geological maps of the South African shelf (Birch et al., 1986). These maps
allowed the sites to be constrained according to surficial textures and sediment characteristics,
although the compilations were not based on cores, but surficial samples which were obtained
from 1967 1981. These proved particularly beneficial in identifying the loci of muddy sediments
on the shelf.
Working area 1, offshore the Limpopo River/Maputo Bay is characterised by a broad
depositional cone. Figures 4.1 to 4.3 show the location of the most prominent cores acquired in
the area. All depth scales are in milliseconds two way travel time. The shelf edge and upper slope
comprise sigmoid prograding, moderate to high amplitude reflectors (Fig. 4.1 and 4.2). At least
two sets of sigmoid packages are evident, the lowermost truncated by a strongly erosional surface
onto which the younger package of sigmoid reflectors onlap (Fig. 4.2). This erosional surface
extends beneath the shelf and forms a series of small scale incised valleys that become prominent
from depths of 70 m (90 ms) to landwards. Overlying this surface are small incised valley fill
sequences, in addition to the second sigmoid prograding unit in the more distal part of the shelf-
upper slope. First interpretations of the data suggest a lowstand shelf valley system that fed
material to a lowstand shelf edge delta. This unit is similarly truncated by a second, high amplitude
reflector that extends onto the outer to mid-shelf. This reflector is less rugged and more planar
than the lower erosional unconformity. Overlying this surface are a series of acoustically
transparent units that onlap a series of rugged pinnacles and ridges (Fig. 4.2 and 4.3). These ridges
overlie the incised valleys of the lowermost erosional reflector. Early interpretations consider these
post-glacial features that overlie the last glacial maximum subaerial unconformity. Green et al.
(2014) interpret these from the adjoining shelf in South Africa as drowned barrier shoreline
systems. The onlapping transparent facies are correlated to the post-glacial early shoreface that
developed near contemporaneously with the barriers. The unconformity separating the two marks
the wave ravinement surface that formed as the shoreface translated over the old barrier-shelf
profile. The lee of the barriers comprises either high amplitude laminated to acoustically opaque
6 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
reflectors (Fig. 4.2) or by acoustically transparent internally featureless units (Fig. 4.3).
GeoB20610 revealed that the former comprises muddy deposits, thought to be contemporaneously
forming back-barrier lagoonal sequences. Preliminary microfossil analyses however indicate the
mud is devoid of any brackish species and is likely a fluvial deposit housed in the available
accommodation behind the barrier form. The latter comprises sandy shoreface material as
evidenced from boxcore GeoB20612.
The mid to inner shelf appears to be controlled by the deposition of material from the main river
sources that is reordered by waves and longshore currents into a shallow, wave-dominated delta.
Variably dipping reflector arrangements (Fig. 4.2) that merge landwards into an onshore
prograding beachridge field attest to this.
Fig. 4.1 PARASOUND profile depicting locations of GeoB20608 and GeoB20609. Both were acquired on a
slope terrace with thick (>20 ms) laminated sediments.
Fig 4.2 Location of GeoB20610 in the landward lee of an aeolianite.
Working area 2 encompasses the shelf offshore the Tugela and Mzimvubu River’s. For brevity’s
sake, the Tugela alone is discussed here. The stratigraphy comprises a shallow bedrock basement
(Cretaceous siltstones), which crops out in places, overlain by thin (<15 ms) sediment cover in the
mid-outer shelf (Fig. 4.4). Like the Limpopo area, this is interrupted by pinnacles and ridges
against which the unconsolidated material onlaps. These features are similarly interpreted as
aeolianite barrier ridges with an onlapping postglacial shoreface respectively. At a depth of ca.
40m (50ms), the sandy shoreface is overlain by a thick blanket of mud. The exact thickness is
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 7
unclear due to gas curtaining (Fig. 4.4), however at least 8,3 m of clay-rich material was retrieved
by GeoB20619-3. This mud forms the prodelta of the wave-dominated Tugela subaqueous delta.
Fig. 4.3 Location of GeoB20613, GeoB20617 and boxcore GeoB20612. Note the sandy lee behind the
aeolianite.
Fig. 4.4 PARASOUND profile of the Tugela Delta. GeoB20619-3 retrieved 8,26 m of muddy sediment from a
gassy layer in the acoustic profile.
One box core (GeoB20603-1) and one gravity core (GeoB20623-1) were taken off the Mzimvubu
River on the continental shelf of Port St Johns. A major canyon extends offshore, towards the east,
and is incised to at least 500 m below the surrounding seafloor (Fig. 4.5). Accumulations of
sediments were identified on the multibeam echosounder, within the structural features and
morphology conducive to entrapment within the canyon. The surface texture and acoustic
characteristics of these sediments suggested that they may represent terrestrial deposits and an
appropriate site was identified.
Working area 3, the South Coast of South Africa, was surveyed for the purposes of
reconnaissance using PARASOUND and multibeam bathymetry, and two vibrocores were
obtained from this region. GeoB20628-1 was obtained east of the Breede River mouth. The maps
of Birch et al. (1986) showed surficial muds which have been postulated to constitute a South
Coast mud belt. In this region, sand delivered by rivers is transported east by longshore drift, while
suspended mud is likely distributed further offshore and transported west by bottom currents to
form the South Coast mud belt (Cawthra, 2014). According to this conceptual model, a -45 m nick
point on the South Coast shelf provides accommodation space for the inshore sediment wedge to
8 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
be preserved and gentle slope of the mid shelf is a likely area of accretion for the muddy deposits,
protected from open ocean swells compared to the flat Agulhas Bank. The vibrocore penetrated
through this mud deposit and the basal Cretaceous siltstones, revealing a ravinement surface at the
contact which is likely remnant of at least the Holocene Transgression. Initial microfossil analyses
have confirmed that this mud unit is populated with marine species.
Fig. 4.5 Location and context of core GeoB20603-1, with multibeam bathymetry as the base.
GeoB20623-1 was obtained from the same canyon, at a water depth of 1000 m.
Fig. 4.6 PARASOUND profile showing the core site of GeoB20628-1 east of the Breede River. The y-axis
indicating the vertical scale is indicated as two-way travel time in milliseconds.
Vibrocore GeoB20629-1 was obtained from a depth of 54 m offshore of the Wilderness
Embayment. Here, during sea-level regressions, both the incision of fluvial channels and the
deposition of back-barrier systems occurred across the continental shelf (Cawthra et al., 2014).
During late low stand/early transgression periods, landward shoreface migration occurred and pre-
existing channel incisions were infilled and pre-existing barriers were truncated. Rapid
transgression, however, allowed the preservation of some back-barrier deposits, possibly aided by
protection from antecedent topography. As sea level neared the present-day elevation, erosion of
the mid-shelf sediments resulted in the development of a Holocene sediment wedge. At this site,
however, the Holocene sediment wedge does not form a thick cover sequence blanketing these
well-preserved terrestrial sediments.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 9
Two Kongsberg multibeam bathymetry systems were used during the M123 cruise. The
EM122, a deep water system was used alongside the EM710 shallow/mid water system. Each
system was used to acquire data within respective operational water depths which allowed the best
possible resolution data to be collected along transects and during transit between working areas.
The multibeam data were used in conjunction with PARASOUND data to confirm seafloor types
observed on the PARASOUND data. The combined data sources were essential in identifying the
site of the Mzimvubu River core, GeoB20623-1, located in the upper reaches of the Mzimvubu
Canyon (Fig. 4.5).
During calm conditions the widest beam angle (70°) was used to collect the widest useful
swath of data; the beam angle reduced as sea conditions deteriorated. Sound velocity profiles were
acquired using SVP-XBTs which were deployed during deep stations. Regular artifacts observed
in the EM710 data were attributed to acoustic interference between the EM710 and PARASOUND
systems whereby the PARASOUND pulse would attenuate the multibeam swath in regular, track
oblique, stripes (Fig. 10). This effect was most noticeable in shallow areas when using a template
to maximize PARASOUND data quality above -100 m.
Fig. 4.7
PARASOUND profile showing
the core site of GeoB20629-1
south of the Wilderness
Embayment. The y-axis
indicating the vertical scale is
indicated as two-way travel time
in milliseconds.
Fig. 4.8
Negative effect of
PARASOUND pulse
on EM710 multibeam
data is shallow waters
10 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
4.2 Sediment Sampling
(E. Schefuß, S. Amberg, N. Du Plesis, A. Hahn, M. Kossack, T.Pillay)
During the M123 cruise four different devices were used to sample ocean bottom sediments, i.e.
the box corer (BC), the multi-corer (MC), the gravity corer (GC) and the vibro corer (VC). While
BC and GC were used at the majority of stations, the MC and VC were only used at selected
stations at which fine-grained or coarse-grained material, respectively, could be expected.
Sediment sampling with box corer (BC)
At sites with unknown surface sediment cover, the BC was deployed first to achieve an impression
of the bottom sediment layer. From all box cores, the surface sediment layer (0-1 cm) was sampled
for investigation of the benthic foraminiferal fauna and heavy mineral content. In cases where
coarse-grained surface sediments were recovered, no additional samples were taken. In cases
where fine-grained surface sediments were recovered, 2 petri-dish samples of the sediment surface
(0-1 cm) were taken, sealed and stored at room temperature. Additionally, a core liner was pressed
into the sediment to retrieve an archive of the sampled material. This liner was cut, sealed with
end-caps and stored at room temperature. The remainder of the intact surface (0-1 cm) of the BC
was scraped off and put into a plastic bag which was stored at room temperature afterwards.
Sediment surface sampling with multicorer
In cases of fine-grained surface sediments, the MC was deployed for recovery of undisturbed
sediment surfaces. The MC was equipped with 8 tubes of 10 cm and 4 smaller tubes of 5 cm in
diameter. The MC was used at 3 stations in the Limpopo area. During all MC deployments
sampling was successful resulting in all filled cores. The surface (0-1 cm) of 2 large cores was
transferred into petri-dishes, which were sealed and stored at room temperature. Two other large
cores were used for surface sediment sampling (0-1 cm) for heavy minerals and benthic
foraminifera. Two other large tubes (equipped with cut VC-liners) were stored at room temperature
as archives. Due to the lack of appropriate sampling material, the remainder of the recovered
material was discarded.
Sediment sampling with gravity corer and vibrocorer
During the M123 cruise 16 sediment cores were recovered using the gravity corer SL-12, and SL-
6. The vibrocorer was used at 3 sites for which sandy sediments were expected. Once a core was
retrieved on the deck, the core liners were cut into 1 m segments, closed with caps at both ends
and labelled according to the scheme applied in MARUM and the Geosciences Department,
University Bremen. All cores were cut along-core in two half pieces: one archive and one work-
half. The sediment sections were described according to IODP rules. The archive halves were then
scanned immediately after opening using a smartcube© camera image scanner taking digital
photos. Camera scanner readings of the ratio 700 nm/400 nm (red/blue ratio) and L* of the core
sediments were derived from these scans. From the work-half one series of samples (ca. 5 ccm)
was taken at irregular intervals. These samples were taken for discrete XRF measurements at
MARUM. Additional samples (ca. 1 per section) were taken for the analysis of heavy mineral
associations and benthic foraminiferal ecology.
The preliminary lithologic summary of the sediments retrieved with the gravity corer is
based on visual description and scanner data.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 11
4.3 Physical Properties
(T. Frederichs, M. Gomes, C. Higgs, A. Hinkeldey, M. Khumalo)
4.3.1 Methods
The sediment series recovered during R/V METEOR Cruise M123 by gravity and vibro coring
were subject to routine laboratory geophysical studies. Shipboard measurements on the segmented
cores were made using a Geotek Multi-Sensor Core Logger (MSCL) and a smartcube® Camera
Image Scanner smartCIS. The MSCL measurements routinely comprise two basic physical
parameters:
electrical resistivity Rs (as a measure of porosity and density),
magnetic volume susceptibility κ
Digital imaging utilizing by the smartcube® Camera Image Scanner smartCIS provided high
resolution down-core images with additional light and color reflectance parameters.
These properties are closely related to the lithology and grain size of the sediments. Electrical
resistivity and magnetic volume susceptibility yield medium-resolution core logs available prior
to all other detailed investigations. The characteristic sensor response width for these parameters
is approximately 5-8 cm and all the cores were measured at 1 cm resolution. Magnetic
susceptibility and electrical resistivity were measured on closed cores, after letting them warm for
a few hours at room temperature. The archive half of each sampled core was optically scanned at
a resolution of 0.005 cm to obtain digital photographs and light reflectance curves.
Magnetic Volume Susceptibility
Magnetic volume susceptibility κ is defined by the equations
B = µ0·µr·H = µ0·(1 + κ)·H = µ0·H + µ0·κ·H = B0 + M
with magnetic induction B, absolute and relative permeabilities µ0 and µr, magnetizing field H,
magnetic volume susceptibility κ and volume magnetization M. It can be inferred from the third
term, κ is a dimensionless physical quantity. It represents the amount to which a material is
magnetized by an external magnetic field.
For marine sediments the magnetic susceptibility may vary, between an absolute minimum
value of around -15·10-6 SI units (diamagnetic value of pure carbonate or silicate) to a maximum
of some 10.00010-6 SI for basaltic debris rich in (titano-) magnetite. In most cases κ is primarily
determined by the ferrimagnetic mineral content, while paramagnetic matrix components such as
clays are of minor importance. High magnetic susceptibilities indicate high terrigenous or low
carbonate deposition. Low values of magnetic susceptibility can also result from post-depositional
reduction of oxic iron minerals. In absence of pervasive diagenesis, magnetic susceptibility can
serve for a correlation of sedimentary sequences deposited under similar conditions. For long-core
measurements a commercial Bartington MS2 susceptibility meter with a 140 mm loop sensor is
mounted on the Geotek MSCL. The Bartington MS2 has an operating frequency of 0.565 kHz and
effective resolution of 210-6 SI. Due to its size, the sensor integrates the response signal over a
core interval of about 8 cm. Consequently, sharp susceptibility changes in the sediment column
appear smoothed in the κ log.
Electrical Resistivity, Porosity, and Density
12 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
The electrical sediment resistivity Rs was determined using an external inductive sensor. A
platinum resistance thermometer (PRT) was used to measure the temperature of a reference core
section. For sensor calibration, a series of saline solutions were measured daily. This calibration is
applied to the measured voltage data during post-processing.
The porosity φ was calculated according to the empirical Archie’s equation,
Rs/Rw = k·φ -m
which approximates the ratio of sediment resistivity Rs to pore water resistivity Rw by a power
function of porosity φ. Following a recommendation by Boyce (1968) for sea water saturated clay-
rich sediments, values of k=1.30 and m=1.45 were used. Density estimates were calculated
assuming a mean bulk density of 2670 kg/m3. For inductive porosity and susceptibility proxies,
we joined the core section data to an entire core log due to a method-immanent non-linear signal
decay toward the section caps. Corrections using an adapted core end correction curve were
applied, but some conspicuous peaks and discordances persist at some section boundaries and
should not be over-interpreted.
Light Reflectance
The smartcube® Camera Image Scanner smartCIS is a special device to make scans of slabbed
and unrolled cores, to create digital archive copies of split core surfaces. The included software
package smartSCAN contains a special interface to communicate with the smartDIS-database.
The digital imaging module of the smartCIS consists of a line-scan camera with triple color
sensor (3 x 4080 Pixel) and lenses with focal lengths of 50 and 75 mm. The camera module
measures the reflected light from two fluorescent tubes illuminating the core from a height of
~5 cm. Archive halves of the core sections were prepared to give a smooth surface. Cores were
usually scanned at a resolution setting of 500 dpi (20 pixel per mm core depth), Depth-of-field
mode set to true/medium and a lens aperture of f8 with auto correction set to off.
The settings used for each core are saved to the respective data files. A white light calibration
was conducted at the beginning of each core taken from a specific site, or when the aperture was
changed. This involves measuring the response of the camera to a white tile of known reflectance
(white calibration).
As part of the post-processing, end-caps were removed from the line scan image. Artifacts were
then identified on the R/B ratio and L graphs and removed. Among other parameters, for each
processed core, the smartCIS software construct depth series for the red, green and blue color
channels, L value (in percent, as measure of total reflectance) and the ratio of the red to blue
channels. L was calculated by the following equations:
R’ = R/255, G’ = G/255, B’ = B/255
L’max = max (R’, G’, B’), L’min = min (R’, G’, B’)
L‘ = INT (L‘max + L‘min) / 2)
L* = L‘·100%
For visualization purposes, two digital core scans of each core were prepared and plotted in all
core logs. The first image shown to the left of each figure represents a non-modified ‘realistic’
photograph of the sediment surface. A second image shown adjacent to the right was enhanced by
modifying the contrast to a value of 75 on a scale ranging between -127 and +127 in order to
emphasize core optical features (cf. Figs. 4.13 – 4.16).
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 13
4.3.2 Shipboard Results
The means and trends of the porosity and susceptibility measurements, as well as core lengths and
water depths, are compiled in Fig. 4.9. Dots indicate the mean values of porosity, derived density
and magnetic susceptibility. Vertical error bars denote the standard deviations. Each diagram is
divided into groups of spatially adjacent cores. Color statistics are not included as absolute
reflectance numbers are controlled by multiple factors and therefore not easy to compare.
Average porosities calculated for gravity cores ranged from about ca. 40% to 56%. Porosity
values in their lower range appear exceptionally dense for unconsolidated marine sediments. Most
porosity values are slightly above 45%. The lowest value (about 40%) was determined for core
GeoB20624-1 which came from deeper water depths, in extension of the Mzimvubu River mouth.
This is in clear contrast to the porosity of 56% measured for the other deep-water core GeoB20620-
4 from the Natal Valley which represented the highest mean porosity of all the cores. In summary,
porosity does not demonstrate any clear dependence on water depth. Corresponding to low mean
porosities, densities are relatively high ranging from 1744 kg/m³ (GeoB20620-4, water depth
3059 m) to 2012 kg/m³ (GeoB20624-1, water depth 2644 m), again indicating no clear general
trend.
Porosity and density data for vibrocore GeoB20622-2 are not shown in Fig. 4.9, since these
values seem to be biased to non-realistic values, due to pore water loss during coring. Voids that
are not completely filled with pore water result in significantly reduced electrical resistivity and
thus decreased porosities and increased densities.
The volume magnetic susceptibility means for cores from the east and south coast are in the ca.
42 to 85210-6 SI range. Core GeoB20609-2 from the deeper part of the Limpopo area shows the
highest mean susceptibility (85210-6 SI). This is more than three times the value of the adjacent
core GeoB20613-2 showing a mean susceptibility of 26910-6 SI, which was recovered from
similar water depth. Absolute values of magnetic susceptibility of several 10010-6 SI (40-260010-
6 SI) are not as low as in areas dominated by more biogenic material as can been seen from core
GeoB20604-1 (mean 710-6 SI) from the south-west coast of South Africa. Cores GeoB20629-1
and 20628-1 from the south coast exhibit also relatively low mean magnetic susceptibilities (42
and 89 10-6 SI, respectively). Higher values represent the expected fluvial fluxes in south-eastern
Indian Ocean. Whether the higher values in the top most layers for cores GeoB20620-4 (up to
420010-6 SI) from the Natal Valley and GeoB20608-1 (up to 300010-6 SI) from the Limpopo area
are coring artifacts is not yet clear. High absolute numbers of magnetic susceptibility with
relatively low variability expressed as standard deviation were found for cores GeoB20607-2 and
GeoB20609-2. This indicates continuously high supply of terrigenous material at these locations,
which are most distant from the Limpopo River mouth compared to other coring sites in this area.
14 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Core images and reflectance data (see Figs. 4.13 4.16) document generally medium dark
greyish-greenish sediment colors for all cores from the Limpopo area (GeoB20607-2, 20608-1,
20609-2, 20610-2, 20613-2, 20615-2, 20616-1, 20617-1) with average L* values of about 40–
45%. In contrast, cores GeoB20621-1 and 20623-1 from more southerly locations off the Tugela
and Mzimvubu Rivers, respectively, comprise of darker colors with mean L* values of around
30%. Cores from deeper water depths (GeoB20620-4, GeoB20624-1) exhibit greater light
reflectance at least in the upper brownish part (GeoB20620-4). This was seen through the whole
Fig. 4.9
Core length, water depth,
mean porosity, density,
and magnetic
susceptibility of all
M123 cores. Vertical
error bars denote
standard deviations.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 15
sediment sequence recovered (GeoB20624-1). Both these cores consist of a more greenish
lithology from the middle to lower parts. Furthermore, the latter parts of both cores show more
pronounced and almost cyclic behavior of high and low light reflectances. Although from a
completely different depositional environment, core GeoB20601-4 shows similar alternations of
high and low reflectivity and red-blue ratios. This is seen to be a lot less variable for the cores from
the east coast of southern Africa. Core GeoB20622-2 is sandier and shows more yellowish colors.
This color continues down to a core depth of 3 meters, with higher reflectivity and mean L* values
of approximately 55%.
West Coast (core GeoB20601-4):
This core shows cyclic behavior around mean values without any trend in color related parameters,
porosity and magnetic susceptibility. The absolute values of magnetic susceptibility are the lowest
of all the cores recovered during the cruise. This points to a very limited influx of terrigenous
material and/or dilution by high amounts of biogenic material. Porosity is almost equal to the cores
from the eastern coast of South Africa. The core with relatively high color reflectance displays a
high red-blue ratio of about 1.6 and up to 1.8 in the upper meter. This indicates an enhanced content
of reddish minerals, probably hematite particles transported by wind.
Limpopo River area (cores GeoB 20607-2 through 20617-1):
This group of cores can be subdivided in three subgroups based on similar patterns of magnetic
susceptibility: group 1 consists of cores GeoB20607-2, 20608-1 and 20609-2 with GeoB20607-2
being the stratigraphically oldest core (Fig. 4.10); group 2 comprises cores GeoB20613-2, 20616-
1 and 20617-1 with GeoB20617-2 reaching most far back into time (Fig. 4.11). The cores of the
third subgroup, GeoB20610-2 and 20615-2, show almost no common features and thus seem to
represent different depositional conditions compared to all other sediment cores from this area.
These cores were taken from water depths between 59 and 485 m, they show low red-blue ratios
of about 1.2 which can increase up to 1.7 in the upper 50 cm of sediment. These increases indicate
more oxic conditions. Porosity and magnetic susceptibility vary for all cores by a factor greater
than two. The optical parameters show lower variability with the exception of core GeoB20617-
1. The color reflectance L* of the latter varies between about 40% and more than 65% with a semi-
cyclic character.
16 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
350
350
400
400
450
450
500
500
550
550
600
600
20608-1
20608-1
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
Sub-bottom depth [m]
Sub-bottom depth [m]
200
200
400
400
600
600
800
800
1000
1000
1200
1200
20609-2
20609-2
400
400
600
600
800
800
1000
1000
20607-2
20607-2
287 m
287 m
459 m
459 m
486 m
486 m
Magnetic Susceptibility [10E-6 SI]
Magnetic Susceptibility [10E-6 SI]
up to 3225
up to 3225
160
160
200
200
240
240
280
280
320
320
360
360
20613-2
20613-2
9.5
9.5
9
9
8.5
8.5
8
8
7.5
7.5
7
7
6.5
6.5
6
6
5.5
5.5
5
5
4.5
4.5
4
4
3.5
3.5
3
3
2.5
2.5
2
2
1.5
1.5
1
1
0.5
0.5
0
0
Su-bottom depth [m]
Su-bottom depth [m]
0
0
200
200
400
400
600
600
800
800
20616-1
20616-1
100
100
200
200
300
300
400
400
500
500
600
600
20617-1
20617-1
459 m
459 m
431 m
431 m
424 m
424 m
Magnetic Susceptibility [10E-6 SI]
Magnetic Susceptibility [10E-6 SI]
Tugela River area (cores GeoB20619-3 and 20621-2):
Core GeoB20621-1 and GeoB20619-3 demonstrate very similar variations and were recovered
from almost identical water depths of 32 and 34 m at almost the same site location. GeoB20621-1
consists of relatively dark sediments showing a mean color reflectance L* of about 30% in the
upper 3 m and 20% in deeper strata. Red-blue ratios are also low with a mean value of about 1.
Relatively high porosities of greater than 60% decreases with a linear trend to about 40% at the
core base. Magnetic susceptibility shows low variability down-core with a mean of 55510-6 SI
and a prominent peak of up to 260010-6 SI at a core depth of ~7 m. The magnetic susceptibility
signal of core GeoB20621-1 can be easily correlated to that of core GeoB20619-3 (Fig. 4.12). This
correlation shows that core GeoB20619-3 loses a part of the topmost sediment layers but cored
Fig 4.10
Magnetic susceptibility
of gravity cores GeoB
20607-2, 20608-1 and
20609-2 from the
Limpopo area. Dashed
lines indicate tentative
correlation tie points.
Fig 4.11
Magnetic susceptibility
of gravity cores GeoB
20613-2, 20616-1 and
20617-1 from the
Limpopo area. Dashed
lines indicate tentative
correlation tie points.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 17
stratigraphically older horizons at the bottom. Both these cores showed the highest variability of
all the cores in each physical parameter.
0
0
400
400
800
800
1200
1200
1600
1600
2000
2000
20619-3
20619-3
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
Sub-bottom depth [m]
Sub-bottom depth [m]
0
0
1000
1000
2000
2000
3000
3000
20621-1
20621-1
Magnetic susceptibility [10E-6 SI]
Magnetic susceptibility [10E-6 SI]
Natal Valley / Deep Agulhas (core GeoB20620-4):
This core was recovered from a water depth of 3059 m and exhibits a significant color change at
about 0.5 m core depth from bright yellow colors to darker greenish colors. Color reflectance L*
decreases from 80% to 40%. Parallel with the color change the red-blue ratio decreases from values
of ~1.7 to 1.2. Porosity shows a slight cyclic behavior that seems to be, at least partly, related to
the fluctuations of color reflectance. Magnetic susceptibility shows a similar pattern but with less
pronounced variations. At the top of the sediment core, magnetic susceptibility reaches the highest
value of all the cores with a value of up to 420010-6 SI. Whether this value is realistic or due to
coring artifacts is still unknown.
Protea Banks (core GeoB20622-2):
This vibro core was recovered from a water depth of about 85 m and shows one of the highest
mean magnetic susceptibilities of all cores (72910-6 SI) with a significant increase at a core depth
of about 1.5 m. The variability of magnetic susceptibility is the highest among all the cores
indicating variable depositional conditions. The upper 3 m show a relatively high color reflectance
with a mean L* of about 55% which then decreases to medium values of about 45%. The red-blue
ratio also exhibits high values (up to around 2) which decrease to values of around 1.5 at a depth
of about 3 m.
Fig. 4.12
Magnetic susceptibility of
gravity cores GeoB 20619-3
and 20621-1 from the
Tugela area. Dashed lines
indicate tentative correlation
tie points.
18 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Fig. 4.13 Optical parameters (color reflectance L*, red-blue ratio) and physical properties of gravity core
GeoB20607-2 from Limpopo River area.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 19
Fig. 4.14 Optical parameters (color reflectance L*, red-blue ratio) and physical properties of gravity core
GeoB20620-4 from Deep Agulhas.
Mzimvubu River and Mzimvubu Canyon (cores GeoB20623-1 and 20624-1):
These two cores were recovered in front of the mouth of the Mzimvubu River and the Mzimvubu
Canyon and stem from significantly different water depths of 671 m (GeoB20623-1) and 2644 m
(GeoB20624-1), respectively. Thus they represent different deposition regimes. While core
GeoB20624-1 shows mostly bright greenish and yellow colors at the topmost 25 cm, core
GeoB20623-01 and GeoB20621-1 from the Tugela River area show the darkest colors of all the
cores recovered with a very low color reflectance of 20 to 30%. Furthermore core GeoB20624-1
exhibits the highest mean density of ~2012 kg/m³ of all the gravity cores. Most of the parameters,
including L*, density and magnetic susceptibility show cyclic behavior suggesting that this core
from relatively deep water depth may have records glacial-interglacial cycles.
Breede River area and Mossel Bay (cores GeoB20628-1 and 20629-1):
These two cores show the lowest magnetic susceptibility of all cores recovered at the eastern and
southern coast (means 89 and 4210-6 SI, respectively). While core GeoB20628-1 shows a
moderate color reflectance of around 40% with an almost constant red-blue ratio of 1.4 which can
increase to values up to 2.1 for core depths greater than 3 m, core GeoB20629-1 exhibits higher
red-blue ratios for the top most 1.5 m which decrease to values of ~1.1 down-core. Its color
reflectance shows a trend to higher values down-core. The red-blue ratio of core GeoB20628-1
varies almost parallel with magnetic susceptibility which is low and almost constant in the upper
2.5 m and increases by a factor of 2 for the lower sediments. For porosity, the two cores show
opposite trends. While in core GeoB20628-1 porosity decreases from high values of ~70% to low
30% down-core, the values increase from 30% to 40% in the upper 4 m of core GeoB 20629-1 and
decrease again further down.
20 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Fig. 4.15 Optical parameters (color reflectance L*, red-blue ratio) and physical properties of gravity core
GeoB20621-1 from Tuguela River area.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 21
Fig. 4.16 Optical parameters (color reflectance L*, red-blue ratio) and physical properties of vibro core
GeoB20629-1 from Mossel Bay.
4.4 Mineralogy
(S. Andó)
Reconstructing the erosion of the eastern passive margin of Africa is a key goal of R/V METEOR
expedition M123, consequently we need to distinguish sediment delivered from different rivers
and their erosional and dispersal pattern under the influence of the Agulhas current along the shelf.
Some of this work requires shore-based provenance studies coupling different bulk methods
(petrography; geochemistry) and single grain methods (heavy-mineral; zircon age; Raman
spectroscopy), but initial mineralogical studies on board are able to pinpoint the contribution of
different rivers using traditional microscopy applied to heavy minerals in smear slides.
4.4.1 Methods
Semi-quantitative studies of the mineralogy of sand to silt size sediments were conducted on board
of the Meteor during expedition M123 using a monocular polarizing microscope Carl Zeiss with
10x, 40x objectives. Classical methods following the “Book” of Mange & Maurer, 1992, where
applied to identify different varieties of heavy minerals. Working with students on board, a table
of properties and photos of all the minerals encountered were prepared to facilitate the proper
identification of the heavy mineral suite in different samples. The light fraction comprising detrital
light minerals and biogenic fragments represents the highest percentage of the sediment by
22 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
composition. We have thus also considered these grains in the table so as to complete the catalogue
of detrital minerals.
Smear slides were prepared using two different procedures. To better identify the grain size,
and to correctly identify single sedimentary layers, a proper smear slide was prepared by spreading
a small amount of sediment on the slide with water. After drying, a few drops of Norland 61
(n=1.54) were added and the slide fixed with a portable UV light.
The second procedure is modified for semi-quantitative heavy-mineral analysis on board and
serves to separate the clay fraction from the sediment. Samples were washed by water, taking care
to avoid loss of the pure sand and silt into the sink. The adopted procedure allows us to better
identify heavy minerals with the polarizing microscope and it eliminates most of the aggregates of
minerals and organic matter, micritic cement and nannofossil muds. A clean smear slide with
heavy grains is ready for grain counting. To speed up the process of counting heavy minerals on
board, and because the number of heavy grains is significantly less than the light and biogenic
fractions, the counting technique “area method” (Mange & Maurer, 1992) was used. Only
transparent and opaque heavy minerals, Ti-oxides, Fe-oxides, glaucony, chlorite, biotite,
authigenic carbonate in euhedral crystals were counted. In this study of the mineralogy of
Southern Africa sediments we have distinguished minerals in the silt to sand grain size window.
These were: zircon, tourmaline, rutile, titanite, apatite, hornblende, actinolite, augite, diopside,
enstatite, hypersthene, spinel, epidote, zoisite, allanite, pumpellyite, chloritoid, garnet, staurolite,
andalusite, kyanite, sillimanite. For each group of minerals we have also described the color to
distinguish varieties. Surficial features of each single grain were also examined to investigate the
possible link between climate and weathering encoded on each single mineral. In particular
pyroxenes and amphiboles develop sharp corrosion features, displaying typically from corroded
to etched and skeletal outlines. It is possible to quantify these characteristics applying a visual
classification proposed in a catalogue of corrosion features by Andó et al. (2012).
4.4.2 Mineralogical suite of heavy-minerals in different working areas
A total amount of 125 samples were collected for onshore heavy mineral and bulk petrography
quantitative analyses for provenance studies. 48 smear slides were prepared and analyzed on board
for heavy mineral semi-quantitative studies and to identify different sources of the detrital input
and their dispersal in the marine environment (Tab. 4.1).
Bay of Maputo:
A total of 28 smear slides were prepared from this working area 1 and 14 were analyzed for the
heavy mineral suite. These ranged from sand to fine silt grain size. In surficial sediments, moving
from the mouth of the Limpopo River to East and in a clockwise direction, following the main
current patterns in the Bay of Maputo, we recognize in samples GeoB20610; 20609; 20607 a
similar assemblage with a moderate to rich amount of heavy minerals, abundant amphibole, 32-
39% and epidote, 22-31%, very common clinopyroxene, 13-25%, subordinate garnet, 3-7 %, and
zircon, tourmaline, rutile (ZTR), 2-7%, with minor orthopyroxene (1-4%) and other heavy
minerals (&HM) 1-3%. Sample GeoB20615 is west of the mouth of the Limpopo River and closer
to the shoreline and it contains a low amount of HM with a very different mineral suite, probably
influenced by the erosion and contribution of the aeolian dunes of Maputo. Epidote is abundant,
33%, with clinopyroxene, 28%, amphibole is common 15%, zircon represents 9%
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 23
Table 4.1
24 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
(aeolian contribution), minor garnet 6%, orthopyroxene 4% and &HM 4%. GeoB20616 is a
transitionary or intermediary sample from the central gyre of the Bay; 20617; 20613; 20608 are
characterized by a very poor assemblage of HM and enriched in forams, biogenic debris and
glaucony within the central part of the current gyre circulation. GeoB20616 contains low amounts
of HM with common epidote, amphibole and clinopyroxene, rare zircon and tourmaline and trace
of apatite, garnet and orthopyroxene. GeoB20617; 20613; 20608 contain very rare or trace of HM
with amphibole and clinopyroxene. In the deeper samples we have a similar trend; concentrations
of heavy minerals but differences among samples in the same core are possible and further
quantitative analyses are indispensable for a proper discussion.
Tugela Mouth area:
7 smear slides from working area 2 were analyzed. All these samples display poor assemblages of
heavy minerals with few varieties. GeoB20620-4 contains low amounts of garnet, epidote,
diopside and hornblende. GeoB20619-3 and GeoB20625-1 have very low amounts of HM with
epidote, garnet and diopside. GeoB20605-1 contains negligible amounts of hornblende. Fine sand
and silt in samples GeoB20604-1, from the area of Port St. Johns and the Mzimvubu River Canyon,
contains a medium to rich suite of HM. The assemblage is dominated by the presence of colorless
or pale green clinopyroxene 41% (derived mostly from the dolerite dikes), common amphibole
(hornblende and actinolite) 26%, frequent epidote 12%, ZTR 12% and garnet 8% and minor &HM.
The sample GeoB20602-1 in front of Port Elizabeth contains low amounts of HM with epidote,
clinopyroxene, zircon, garnet and glaucony.
Mossel Bay:
GeoB20628 displays recycled sediments from Cretaceous sediments with only minor quantities of
HM with abundant zircon and glaucony. GeoB20629 is a fine, well sorted sand, with very low
amounts of HM. Common minerals include garnet and subordinate etched clinopyroxenes and
unweathered zircon. The only sample collected in the Western Coast of South Africa is
GeoB20601-4 which was dominated by biogenic sediments, foraminiferal sand with nannofossils
or bioclastic sand with abundant forams and glaucony without undetectable amounts of HM.
4.4.3 Discussion
This heavy mineral assemblage in the Work area 1 in the Bay of Maputo is very similar to the
modern Limpopo River composition (Garzanti et al, 2014) but an important contribution from the
deflation of the dune field of Maputo is also a possible factor in feeding ultra-stable minerals to
the system. The rounded quartz grains are likely to effectively dilute the amount of pyroxene
derived from the Olifants to the Limpopo River. The high content of amphiboles provided by
Kapvaal and Zimbabwe Cratons could be affected by the local gyre circulation in the Bay of
Maputo, where sediments from the Limpopo River are entrained in the SE to NE current with an
accumulation of ultra-dense zircon and garnet in sample GeoB20610 and an increasing amount of
hornblende in samples 20609 and 20607. In this trajectory, sediments poor in heavy minerals reach
the area marked by samples 20615 and 20616 where a SE contribution from the offshore deflation
of coastal dunes adds abundant quartz and zircon. The central area of the gyre system is a relatively
high productivity zone with very abundant biogenic fractions and very poor heavy minerals
content (dilution effect). Furthermore, a strong link to the Limpopo River is demonstrated by the
presence of amphibole and epidote derived from the continental block of the old cratons, and
pyroxene, with a marker-mineral, the green-pink hypersthene derived from the erosion of the
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 25
Bushveld Complex and carried by the Olifants a tributary of the Limpopo River to the marine
environment.
The adopted “area method” could affect the described percentages of heavy minerals and a
“point counting” method is advisable for a quantitative analysis to be conducted onshore
(Galehouse, 1971). In this light, epidote could be overestimated because in marine samples it is
usually smaller than amphiboles and pyroxenes. Corrosion features are very common on
pyroxenes and less common on amphiboles and epidotes, so we have to take into account a possible
surficial weathering effect on the observed suites of heavy minerals. This is possible after weighing
the HM fraction in the laboratory for provenance studies of Milano-Bicocca, Italy after onshore
heavy mineral gravimetric separations.
The relative abundance of different heavy minerals in a quantitative study is possible,
comparing our newly collected data set with the modern dataset on land (as published in previous
studies) and future analyses on additional samples collected in the Limpopo catchment during
previous MARUM expeditions.
4.5 Microfossils
(P. Frenzel, E. Bergh, L. Gander, K. Strachan)
The sampling and preliminary analysis of microfossils sampled during R/V METEOR Cruise
M123 had two main objectives; 1) the documentation of recent fauna, focusing primarily on
Foraminifera and Ostracoda, thus developing taxonomic reference material and
ecological/distribution data as a base for later analysis of fossil material from marine sediment
cores, and 2) preliminary descriptions of associations from extracted cores, providing an overview
on the general distribution patterns (abundances, P/B ratio), maximum ages of cores relying on
biostratigraphical analysis and first insights into depositional environments by palaeoecological
interpretation. Macrofossil extracted from sediment cores during the documentation by other
working groups were identified and an interpretation given.
4.5.1 Methods
All core and surface samples were wet sieved using seawater through a 63 µm and 1000 µm sieve,
separating the bigger components from the smaller components. Sieved surface samples were
examined under a binocular microscope for both living ostracods and foraminifera. Living
ostracods were collected and stored separately in ethanol, while living foraminiferal specimens
were dried. A short documentation and description of each sample was compiled before adding
Rose Bengal to each surface sample to stain the soft parts of any living foraminifera. Following
this step samples were dried in an oven at 60°C.
4.5.2 Description of Surface Samples
The following descriptions are based on the visual inspection of the surface sediments in each of
the box cores and multi-cores, and on qualitative microscopical observations of sieved sediment
samples (>63 µm). See Figure 3.1 for positions of sampling stations. A remarkable observation
was the generally abundant presence of glauconite in foraminifera tests from the upper slope.
GeoB20602-1:
Habitat: green mud, no anoxic layer visible, faecal pellets and some black concretion of mm-scale,
rare glauconite
26 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Fauna: some tubes of crayfish, shell detritus and
Scaphopoda, rich foraminifera fauna (Ammonia,
Elphidium, Amphicoryna, Cassidulina, Miliolids,
Lagena, rare planktonic foraminifera), rich
ostracod fauna (two alive), fragments of
Mollusca, Bryozoa and Echinodermata
Interpretation: well preserved recent inner shelf
soft bottom association on older (Pleistocene?)
sediments
Fig. 4.17 Sieved surface sample in BC GeoB20602-1 (>63 µm)
GeoB20603-1:
Habitat: carbonate sand, surface well-oxygenated, coarse sand with larger shell fragments, 90 %
biogenic fragments, 10 % moderately rounded
quartz
Fauna: fragments of Mollusca, Bryozoa and
Echinodermata, well preserved foraminifera
(miliolids, Elphidium, Lenticulina, Lobatula, rare
Ammonia, Amphicoryna and planktonic
foraminifers), only a few living animals
(Amphipoda and fixosessile foraminifera)
Interpretation: sorted shell accumulation, mostly
allochthonous, turbulent water
Fig. 4.18 Sieved surface sample in BC GeoB20603-1 (>63 µm)
GeoB20604-1 (off Mzimvubu River):
1mm
1mm
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 27
Habitat: green to brown mud, oxygenated, little
agglutinated tubes at the surface, faecal pellets,
rich in organic detritus.
Fauna: diverse benthic and planktonic
foraminiferal species (large agglutinated forms:
Reophax, Rhabdammina (mm-scale), mioliolids,
lagenids), rare Ostracoda, mostly dead, only a
few living individuals, Crustacea and worms,
juvenile shells, many Radiolaria.
Interpretation: autochthonous bathyal association
from a submarine canyon, bottom current
indicated by filter feeders.
Fig. 4.19 A) Sieved surface sample in BC
GeoB20604-1 (>63 µm); B) Large elongated
agglutinated foraminifers Rhabdammina(?)
GeoB20605-1 (off Tugela River):
Habitat: brown sand, well sorted, very coarse,
well oxygenated, subangular to angular quartz,
feldspar, rock fragments and blackish concretions
Fauna: low proportion of biogenic material, low
diverse fauna, reworked biogenic material, some
well-rounded, no planktonic foraminifera, some
benthic foraminiferal species (Ammonia,
miliolids, polymorphinids), juvenile shells and
corals, fragments of Mollusca, Bryozoa,
Echinodermata and Balanidae, no Ostracoda,
some Scaphopoda, some snails, one living
ophiuroid
Interpretation: well sorted littoral sand
Fig. 4.20
Sieved surface sample in BC
GeoB20605-1 (>63 µm)
GeoB20607-1 (Limpopo fan):
Habitat: foraminiferal ooze, sand with low proportion of detritus, clay intraclasts, angular quartz,
small blackish concretions, glauconite
0.5mm
1mm
A
B
1mm
1mm
28 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Fauna: microfossils and macrofossils (solitary corals, Echinodermata, Balanidae, benthic and
planktic Gastropoda, bivalves, Bryozoa), mollusk fragments, planktic foraminifers dominant
(globigerinids + Globorotalia, Orbulina),
lagenids (Laevidentalina, Amphicorina etc.),
agglutinated forms, Quinqueloculina,
Cibicidoides, Bolivina, Pyrgo, few ostracods
Interpretation: bathyal globigerinid ooze, slope
association
Fig. 4.21
Sieved surface sample in MC
GeoB20607-1 (>63 µm)
GeoB20608-2 (Limpopo fan):
Habitat: muddy sand, small proportion of organic detritus, at the surface agglutinated tubes, sand
with small blackish concretions, with some foraminiferal grains of glauconite, small subangular
quartz
Fauna: rich fauna of planktonic foraminiferal species (globigerinids, Globorotalia, Orbulina),
some taxa of benthic foraminifers (Cibicidoides, lagenids (Laevidentalina, Lenticulina,
Saracenaria, Nodosaria), Pyrgo, Spiroloculina, many sponge spicules, ostracods are very rare
(only one living ostracod) Interpretation: bathyal globigerinid ooze, slope
association
Fig. 4.22 Sieved (>63 µm) surface sample of MC
GeoB20608-2
GeoB20609-1 (Limpopo fan):
Habitat: sand with low proportion of detritus, small blackish concretions, angular quartz,
glauconite
Fauna: fragments of bivalves, Echinodermata,
Bryozoa, planktic Gastropods, planktonic
foraminifera dominant (globigerinids +
Globorotalia, Orbulina), Cibicidoides, lagenids,
otoliths, Spiroloculina, some agglutinated
foraminifera, Scaphopoda, some sponge spicules,
and rare ostracods
Interpretation: bathyal globigerinid ooze, slope
association
1mm
1mm
1mm
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 29
Fig. 4.23 Sieved (>63 µm) surface sample of MC GeoB20609-1
GeoB20610-1 (Limpopo fan):
Habitat: greenish brown, sandy mud, fine-grained and well sorted, oxygenated surface (up to 1cm),
sand with high proportion of detritus, much more detritus than biogenic minerals, small blackish
concretions and many faecal pellets, subangular to angular grains of quartz and feldspar, rock
fragments and mica, rare glauconite
Fauna: mud with bivalves, Crustacea, snails, worms and echinoids, polychaets, juveniles and
fragments of bivalves, Echinodermata, Bryozoa, rare planktonic foraminiferal species
(globigerinids, Globorotalias, Orbulina), benthic
foraminifera (Ammonia, Quinqueloculina,
elphidiids, lagenids (rare), bolivinids), small
ostracods (4 living)
Interpretation: sublittoral habitat with high
terrigenic input
Fig. 4.24 Sieved (>63 µm) surface sample in the BC GeoB20610-1
1mm
30 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
GeoB20611-1 (Limpopo fan):
Habitat: brownish green, sandy mud, fine-grained and very well sorted, oxygenated surface, high
proportion of detritus, much more detritus than biogenic material, small blackish concretions and
many faecal pellets, angular grains of quartz, feldspar and rock fragments, greenish grains are
dominant, glauconite
Fauna: fragments of bivalves, Echinodermata,
Bryozoa, planktonic foraminifera (globigerinids,
Globorotalia, Orbulina), Cibicidoides, lagenids,
bolivinids, Ammonia (rare), Lenticulina,
Spiroloculina, Quinqueloculina, Dorothia, many
ostracods (7 living)
Interpretation: sublittoral soft bottom association
Fig. 4.25 Sieved (>63 µm) surface sample in the BC
GeoB20611-1
GeoB206012-1 (Limpopo fan):
Habitat: brown sand, well-sorted, coarse-grained, well oxygenated, subangular to angular grains,
quartz, feldspar, rock fragments, and blackish concretions
Fauna: low proportion of biogenic material, low diversity fauna, fragments of bivalves,
Echinodermata, Bryozoa, some agglutinated tubes, some Scaphopoda, some snails, some
reworked biogenic material, no planktonic foraminiferal species, no ostracods, rare benthic
foraminifera (lagenids, Quinqueloculina, Ammonia)
Interpretation: shallow sublittoral interstitial association
GeoB206013-1 (Limpopo fan):
Habitat: sand with low proportion of detritus, quartz, feldspar or rock fragment very rare, angular
grains, small blackish concretions, much glauconite, some faecal pellets
Fauna: fragments of bivalves, Echinodermata, Bryozoa, foraminiferal ooze with dominant planktic
foraminifers (globigerinids + Globorotalia, Orbulina), Cibicidoides, and rare lagenids,
Quinqueloculina, Textularia, Bulimina, Uvigerina, some ostracods, Scaphopoda, rare Polychaeta
and some sponge spicules, worm tubes
Interpretation: bathyal globigerinid ooze
GeoB206015-1 (Limpopo fan):
Habitat: brown mud, low proportion of detritus, only few very small quartz grains (angular), high
proportion of organic material, colony of tube dwellers
Fauna: many fragments and suspended organic material, fragments of bivalves, Echinodermata,
Bryozoa, Pteropoda -fragments, benthic Gastropoda, Cibicidoides, globigerinids + Globorotalia,
Orbulina, Quinqueloculina, lagenids, Amphipoda, Scaphopoda, some Ostracoda
Interpretation: deep sublittoral soft bottom association
1mm
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 31
Fig. 4.26 Sieved (>63 µm) surface
sample of BC GeoB206015-1
Fig. 4.27 Large, agglutinated foraminifera from BC GeoB206015-1, the test of Ammodiscus (lower left) has a
diameter of about 1.5 mm
GeoB 206019-1 (off Tugela River):
Habitat: brown mud, very high proportion of detritus, well sorted, fine-grained, angular to
subangular quartz and feldspar, lots of mica (greenish), pyrite, rock fragments, small blackish
concretions, many faecal pellets and biogenic material
Fauna: some fragments of bivalves, Echinodermata, Bryozoa, snails (some living), Scaphopoda
and Bivalvia (some living), rare benthic foraminifera (miliolids, Ammonia, lagenids, Elphidium),
rare planktonic foraminifera (globigerinids, Orbulina), very rare Ostracoda, some body parts of
Crustacea
Interpretation: sublittoral oxygen poor soft bottom assemblage, shell dissolution
1mm
32 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
GeoB 20622-1 (off Tugela River)
Habitat: shell detritus with very low proportion
of detritus
Fauna: mostly fragments of bivalves,
Echinodermata, Bryozoa, rare benthic
foraminifera, rare planktonic foraminifera
(globigerinids), rare Ostracoda
Interpretation: biogenic intertidal or shallow
sublittoral sand (old?)
Fig. 4.28 Sieved (>63 µm) surface sample of BC GeoB206022-1
GeoB 20624-2 (off Mzimvubu River):
Habitat: brown mud, low proportion of detritus, small quartz and feldspar grains (angular), fine-
grained, many faecal pellets and high proportion of organic material
Fauna: rare fragments of bivalves, many
agglutinated benthic foraminifera
(Rhabdammina abyssorum, Bathysiphon,
Cyclammina), rare benthic foraminifera
(Pyrgo), an abundance of planktonic
foraminifera (globigerinids, keeled and
unkeeled Globorotalias, Orbulina), rare
Pteropoda
Interpretation: bathyal foraminiferal mud
Fig. 4.29 Sieved (>63 µm) surface sample of BC GeoB206024-2
4.5.3 Microfauna From Surface Samples
As expected, the abundance of ostracods was lower than that of foraminiferal assemblages
(Fig. 4.30, Tab. 4.2). Ostracods are about ten times less abundant than foraminiferal assemblages
and are predominantly missing from high-energy deposits. They show their maximum abundance
on the shelf not on the slope as that of foraminifera. In general, the number of both groups is
sufficient for quantitative analysis in most samples relying on a few grams of sediment. Living
benthic foraminifera were found in almost all samples but in very low proportions only. However,
with the exception of two samples containing high proportions of living individuals. The one
sample was predominantly mud with calcareous shells bearing dissolution marks and the other
was well-sorted sand. Both indicate dissolution and the transport of empty tests explaining the
high proportions of living individuals.
Plotting P/B ratios along the water depth gradient indicates a clear correlation and a value of
about 50 % for the shelf break as known from literature. Two samples from the slope of the
Limpopo area, however, show markedly increased values (Fig. 4.31). Those typical high P/B ratios
lie in the centre of the investigated area off the Limpopo mouth. Because benthic foraminiferal
numbers are low in this part, increased P/B ratios indicate a higher absolute number of planktonic
1mm
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 33
foraminiferal assemblages. Higher sedimentation rates of pelagic forms may be explained by
inflow and sedimentation within a gyre slowing down in this area.
Fig. 4.30 Total abundances (living + dead) of benthic Foraminifera and Ostracoda in surface samples
Table 4.2 Abundance data and water depth for surface samples. The estimated water depth is calculated relying
on P/B ratios (excluding sample GeoB20624-2).
Sample
Sediment
water dept
h [m]
estimated water depth [m]
Ostracoda [valves/ml]
planktic Foraminifera [tests/ml]
benthic Foraminifera [tests/ml]
living benthic Foraminifera [%]
P/B ratio [%]
reworked microfossils [specimens/ml]
GeoB20602-1
sandy mud
117
102
415
2258
3732
3.7
37.7
1336
GeoB20603-1
shell detritus
75
35
1
12
81
0.0
12.5
159
GeoB20604-1
mud
668
386
16
228
102
4.2
69.0
0
GeoB20605-1
coarse sand
69
65
1
8
20
31.3
27.3
41
GeoB20607-1
globigerina ooze
485
375
180
20160
9360
0.0
68.3
0
GeoB20608-2
muddy fine sand
286
813
386
30879
4825
0.0
86.5
0
GeoB20609-1
muddy sand
461
287
1
7141
4375
1.5
62.0
64
GeoB20610-1
fine sandy mud
59
119
317
2016
2851
2.0
41.4
0
GeoB20611-1
fine sandy mud
120
127
138
4055
5391
6.0
42.9
0
GeoB20612-1
coarse sand
88
38
9
17
96
11.3
14.7
101
GeoB20613-1
globigerina ooze
424
1001
922
92621
8755
0.0
91.4
0
GeoB20615-1
organic mud
200
213
1152
8832
7219
3.2
55.0
77
GeoB20619-1
organic mud, angular
quartz, rock fragments
32 37 5 20 128 60.0 13.8 3
GeoB20622-1
shell detritus
84
108
6
49
76
3.4
39.2
191
GeoB20624-2
mud
2641
1162
461
14861
806
0.0
94.9
0
34 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Fig. 4.31 Plankton/Benthos (P/B) ratio of the studied surface samples plotted on water depth
4.5.4 Core GeoB20601-4 From the Western Continental Margin
Facies: Deep marine, olive-gray mud. Non-biogenic grains include glauconite and small angular
quartz.
Fauna: Ostracoda (few), Radiolaria (rare), echinoid spines (common), sponge spicules (common),
abundant foraminifera (>95% in all sand fraction samples) planktonic foraminifera more
abundant than benthic foraminifera. Planktonic foraminifera include Globorotalia inflata
(abundant), Globigerina bulloides (common), Orbulina universa (common), Globorotalia
truncatulinoides (common), Globigerinella siphonifera (few), Globorotalia hirsuta (few),
Globorotalia menardii (few), Globorotalia scitula, (occur in some samples), Globigerinoides
ruber white (few in most samples), Globigerinoides ruber pink (rare), Globigerinoides sacculifer
(rare), Neogloboquadrina pachyderma (occur in most samples), Neogloboquadrina incompta
(occur in some samples), Neogloboquadrina dutertrei (occur in most samples), Orbulina bilobata
(few).
Benthic foraminifera include Ammonia beccarii (rare), Amphicoryna scalaris (rare), Brizalina
spp. (common), Bulimina spp. (common), Cassidulina laevigata (common), Cibicidoides spp.
(common), Dentalina spp. (few), Eggerella bradyi (rare), Ehrenbergina spp. (rare), Elphidium
advenum (rare), Epistominella exigua (common), Favulina hexagona (few in some samples),
Fissurina spp. (rare), Fursenkoina bradyi (few), Globobulimina spp. (common), Gyroidina sp.
(few), Karreriella bradyi (rare), Lagena spp. (few in most samples), Lenticulina spp. (rare),
Lobatula lobatula (rare), Martinottiella communis (rare), Melonis barleeanum (few), Miliolids
(frequent occurrence), Nodogenerina sp. (rare), Nodosaria spp. (few), Nonionella sp. (few),
Oridorsalis umbonatus (few), Plectofrondicularia sp. (few), Pullenia bulloides (few), Pyrgo spp.
(few), Sigmoilina sp. (few), Siphotextularia sp. (rare), Trifarina sp. (rare), Uvigerina spp.
(abundant).
Remarks: Many benthic foraminifera indicate a deep marine environment. The abundance of
planktonic over benthic foraminifera indicates a depositional environment on the continental slope.
The presence of Ammonia beccarii, Elphidium advenum and Lobatula lobatula among deep-water
taxa in the uppermost portion of the core suggests transport from the shelf.
The presence of Globorotalia truncatulinoides throughout the core gives the age as Pleistocene.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 35
4.5.5 Cores from the Eastern Continental Margin
Core samples from the eastern continental margin usually have a similar planktonic foraminiferal
faunal composition. Abundances of species between cores may vary. Below is a summary of
planktonic foraminiferal species and general abundances.
Globigerina bulloides Only in some cores – low abundance
Globigerinella siphonifera Occurrence in most cores generally low abundance
Globigerinoides conglobatus Common, but generally in low abundances
Globigerinoides ruber Common (pink forms only in a few cores in very low
abundances)
Globigerinoides sacculifer Common, but generally in very low abundances
Globigerinoides trilobus Occurrence in most cores in low abundances
Globorotalia inflata Occurrence in most cores generally low abundance
Globorotalia menardii Common
Globorotalia truncatulinoides Common, but generally in low abundances
Globoturborotalida rubescens pink Only in a few cores – low abundance
Neogloboquadrina dutertrei Occurrence in most cores generally low abundance
Neogloboquadrina pachyderma Only in some cores – low abundance
Neogloboquadrina incompta Few
Orbulina bilobata Few
Orbulina universa Common
Pulleniatina obliquiloculata Occurrence in most cores generally low abundance
Sphaeroidinella dehiscens Only in a few cores – low abundance
The occurrence and abundance of the warmer water species Globorotalia menardii are generally
higher in the eastern margin cores as compared to samples from GeoB20601-4 from the western
margin; while the dominant planktonic in the core from the western margin Globorotalia inflata
deceases along the eastern margin. The occurrence and abundance of other warmer water species
Globigerinoides ruber and Gs. sacculifer also increase, although marginally in samples from the
eastern margin.
Benthic foraminifera in cores from the eastern margin also reflect warmer water conditions with
larger forms present such as Amphistegina lesonii, Heterostegina depressa and Operculina
complanata (Tab. 4.3), and the
increase in occurrence and
abundance of miliolids (Fig. 4.32).
Fig. 4.32
High abundance of Spiroloculina
communis in core GeoB20615-2
36 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Table 4.3 Benthic foraminifer taxa in gravity cores. Each gravity core is indicated by its number, e.g. GeoB20607-
2 is given as 07-2.
07-2
08-1
09-2
10-2
13-2
15-2
16-1
17-1
20-4
21-1
23-1
24-1
Agglutinids
x
x
x
x
x
x
x
x
x
x
x
Ammonia becarii
x
x
x
x
x
x
x
x
x
x
Amphicoryna spp.
x
x
x
x
x
x
x
x
x
Amphistegina lesonii
x
x
Anomalinoides
sp.
x
x
x
x
Bolivina sp.
x
x
Brizalina spp.
x
x
x
x
x
x
x
x
x
Bulimina
spp.
x
x
x
x
x
x
x
x
Cancris spp.
x
x
x
x
x
x
Cassidulina laevigata
x
x
x
Chilostomella oolina
x
x
x
x
Cibicidoides spp.
x
x
x
x
x
x
x
x
x
x
Elphidium spp.
x
x
x
Fissurina
sp.
x
x
x
x
Frondicularia sp.
x
Globobulimina sp.
x
x
x
x
x
x
x
x
Globocassidulina subglobosa
x
x
x
x
x
x
Heterostegina depressa
x
Hyalinea balthica
x
x
x
Lagena
sp.
x
x
x
Lenticulina spp.
x
x
x
x
x
x
x
x
x
Lobatula lobatula
x
x
x
x
x
x
Melonis spp.
x
x
x
x
x
Nodosaria spp.
x
x
x
x
x
x
x
Nonion boueanus
x
x
Nonionella sp.
x
Operculina complanata
x
x
Oridorsalis umbonatus
x
x
x
x
Pigmaeaseiston sp.
x
x
Planularia sp.
x
Pseudorotalia schroeteriana
x
Pullenia bulloides
x
x
x
x
x
Pyrgo sp.
x
x
x
x
x
x
x
x
x
x
x
Sigmopyrgo vespertilio
x
x
Spiroloculina spp.
x
x
x
x
x
x
x
Quinqueloculina sp.
x
x
x
x
x
x
x
x
x
x
Saracenaria italic
x
x
Siphonina tubulosa
x
x
Uvigerina (hispid)
x
x
x
x
x
x
x
x
Uvigerina spp. (ribbed)
x
x
x
x
x
x
x
x
x
Vaginulopsis sp.
x
x
All core catcher samples and additional down core samples, in average ten samples per core, were
analysed stratigraphically based on occurrences of planktonic and benthic foraminiferal index
species (Tab. 4.4).
Selected samples from cores in the Limpopo fan were analysed for foraminiferal abundances.
Qualitative faunal changes within the cores were documented and interpreted preliminary
(Fig. 4.33).
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 37
Table 4.4 Biostratigraphically constrained maximum ages of sediment cores
GeoB20601-4
max. Plio-Pleistocene
GeoB20607-2
max. Pleistocene
GeoB20608-1
max. Plio-Pleistocene
GeoB20609-2
max. Pleistocene
GeoB20610-2
Holocene
GeoB20613-2
max. Pleistocene
GeoB20615-2
max. Plio-Pleistocene
GeoB20616-1
max. Pleistocene
GeoB20617-1
>MIS38(?)
GeoB20620-4
max. Pleistocene
GeoB20622-2
max. Pleistocene
GeoB20624-1
max. Pleistocene
GeoB20628-1
Upper Cretaceous
GeoB20629-1
Holocene
Fig. 4.33 Sediment cores from the Limpopo fan with biostratigraphical information, P/B ratios and preliminary
palaeoecological interpretation
38 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
4.5.6 Macrofossils for Dating
During description and sampling of the cores, macrofossils were taken for later 14C-dating. Such
macrofossils were identified and classified according to their mode of life (Tab. 4.5).
Table 4.5 Macrofossils from sediment cores isolated for 14C dating
core
depth
[cm]
Taxon
Preservation
Remarks
GeoB20607-2
184
Gastropoda
well preserved fragment
No
GeoB20607-2
190
Cavolinia tridentata
complete, broken
planktic gastropod
GeoB20607-2
190
Xenophora sp.
complete, broken
large epibenthic gastropod
GeoB20607-2 417
fragments of benthic and
planktic gastropods + bivalves
shell accumulation allochthonous?
GeoB20607-2
473
Dentalium
sp.
Complete
shallow endobenthic scaphopod
GeoB20607-2
482
Limopsis aurita
one complete valve
epibenthic bivalve
GeoB20607-2
520
?Tellina sp.
double valved (autochthonous!)
endobenthic bivalve
GeoB20607-2
541
?Ctena sp.
one complete valve
shallow(?) endobenthic bivalve
GeoB20607-2
606
Bryozoa
Fragment
allochthonous?
GeoB20607-2
682
Cavolinia ?tridentata
Complete
planktic gastropod
GeoB20607-2 742
Cuvierina sp., ?Turritella sp.,
Nuculana sp.
all complete, but in shell layer
planktic and benthic gastropod
+ shallow endobenthic bivalve
GeoB20607-2
745
?Turritella
sp.
Damaged
Gastropod
GeoB20608-1
37
Cavolinia tridentata
Complete
planktic gastropod
GeoB20608-1
41
serpulid(?) tube
well preserved fragment
epibenthic, fixosessile
GeoB20608-1
91
Terebra sp.
Complete
epibenthic? Gastropod
GeoB20608-1
163
Marginella sp.
Complete
Gastropod
GeoB20608-1
CC
Conus sp.
almost complete
epibenthic gastropod
GeoB20609-1 MUC
agglutinated tube (Polychaeta
or Crustacea)
Fragment endobenthic filter feeder
GeoB20609-2
31.5
Cavolinia tridentata
Complete
planktic gastropod
GeoB20609-2
90
Cavolinia tridentata
complete, broken
planktic gastropod
GeoB20609-2
299
Nuculana sp.
double valved (autochthonous!)
shallow endobenthic bivalve
GeoB20609-2
316
?Tellina sp.
one damaged valve
endobenthic bivalve
GeoB20609-2
398
?Tellina sp.
one fragmented valve
endobenthic bivalve
GeoB20609-2 400 Muricidae
complete, damaged, with
balanids
epibenthic? Gastropod
GeoB20609-2
413
Cavolinia tridentata
Complete
planktic gastropod
GeoB20609-2
367-
467
Cuvierina sp. Complete planktic gastropod
GeoB20609-3
604
?Turritella
sp.
slightly damaged
Gastropod
GeoB20610-2 15
Cerastoderma sp. + gastropod
fragment
one large fragment each shallow endobenthic bivalve
GeoB20610-2
52
Cerastoderma sp.
one complete valve
shallow endobenthic bivalve
GeoB20610-2
69
Macoma sp.
one complete valve
shallow endobenthic bivalve
GeoB20610-2
71
Macoma sp.
one complete valve
shallow endobenthic bivalve
GeoB20610-2
86
Macoma sp.
double valved (autochthonous!)
shallow endobenthic bivalve
GeoB20610-2
95
Limopsis aurita
one complete valve
epibenthic bivalve
GeoB20610-2
127
?Muricopsis
sp.
Complete
Gastropod
GeoB20610-2
271
Pisanianura ?grimaldii
Complete
Gastropod
GeoB20610-2
292
Terebra sp.
one slightly damaged shell
epibenthic? Gastropod
GeoB20613-2
215.5
Scleractinia
fragmented (complete?)
solitary coral
GeoB20613-2
241
?Nasopharus sp.
one valve, fragmented
deep endobenthic bivalve
GeoB20615-2
277
Cerithium
sp.
Complete
epibenthic gastropod
GeoB20615-2
355
Wood
Fragment
terrestrial
GeoB20616-1
632
Limopsis aurita
double valved (autochthonous!)
epibenthic bivalve
GeoB20616-1
634
?Turritella sp.
slightly damaged
gastropod
GeoB20616-1
664
Scleractinia
Complete
solitary coral
GeoB20617-1
195
?Xenophora sp.
crushed fragment
epibenthic gastropod
GeoB20621-1
695
?Tellina sp. + attached balanids
complete valve
endobenthic bivalve
GeoB20628-1
54
Turritella
sp.
slightly damaged
gastropod
GeoB20628-1
187.5
Mactra
sp.
complete valve
infaunal bivalve
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 39
4.6 Plankton Sampling
(Siccha, M., Strachan, K, Hoffmann, D., Kossack, M.)
4.6.1 Sampling and Sample Preparation
The purpose of plankton sampling was the collection of planktic foraminifera for molecular
genetic studies and habitat characterization. Sampling was conducted with a Multi Plankton
Sampler (MPS) [HydroBios, Kiel, Germany]. The used device has a 50 × 50 cm opening and five
net bags with 100 µm mesh diameter. A water sampler with 5 niskin bottles (1.8 L volume) and a
CTD M90 [Sea and Sun Technology, Trappenkamp, Germany] were mounted on the body of the
MPS.
A total of 6 stations were sampled with 19 individual MPS casts. Three standard sampling depth
schemes with fixed sampling interval boundaries were used at each station; a deep cast with a
maximum depth of 700 m (700–500–300–200–100–0 m sampling interval boundaries), a shallow
cast with a maximum depth of 100 m (100–80–60–40–20–0 m sampling interval boundaries), and
a filter cast with a maximum depth of 500 m (500–300–150–80–40–0 m sampling interval
boundaries). Exceptions to this pattern were stations GeoB20626, where the filter cast sampling
scheme was used twice in succession. Closing depths for all strict vertical net hauls were based on
depth calculated from pressure readings of the pressure sensor on the net body. Slacking and
hoisting was done at 0.5 m/s rope speed. The water sampler was used to obtain water samples for
δ13C and δ18O analysis. The attached CTD recorded temperature, salinity, oxygen, chlorophyll a
and pH in one decibar intervals for the MPS deployments. The net bags of the MPS were washed
with sea water and inspected for damage after each net haul; the net cups were rinsed and cleaned
with filtered sea between deployments and in an ultrasonic bath between stations.
The samples obtained from the first (deep) and second (shallow) MPS cast were mostly
conserved as plankton concentrates, a few samples were picked that is the planktic foraminifera
extracted under stereo-microscopes and transferred onto micropaleontological sample slides.
Plankton concentrates and sample slides were deep frozen at .80°C. The samples of the third (filter)
MPS cast at each station were dedicated to the genetic analysis via Next-Generation-Sequencing
(NGS). The obtained plankton concentrates from this net haul were filtered over 8-12 µm pore
size cellulose filters in a vacuum filtration system. Samples were wet-sieved over 1000 µm sieves
to remove the larger zooplankton organisms before filtration. The canisters and filter caskets were
carefully cleaned between filtration of different samples to avoid contamination. The obtained
filters were deep frozen and stored at -80°C. All frozen samples, slides, plankton concentrates and
filters will be shipped with dry ice to the University of Bremen at the end of cruise M126. Water
for isotope analysis was obtained from the deep and shallow casts in 2 ml (δ18O) and 15 ml (δ13C)
vials. Water samples for δ13C analysis were poisoned with 45 µl saturated Mercury chloride
solution.
The sampling conditions for the MPS were difficult due to the strong current of up to 6 knots
at several sites within the Agulhas. The angle of the ship’s rope to the MPS in the water reached
values of 45° resulting in a quasi semi-horizontal tow. The attached water sampler suffered from
mechanical malfunction at the beginning of the cruise so that water could not be sampled during
all casts. The CTD suffered from problems with its power supply, so that casts could only be
recorded at three of the six sites of deployment.
40 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
4.6.2 Plankton Sampling Preliminary Results
Without the detailed counting results, preliminary results are limited. Since we want to conserve
all samples for an eventual genetic analysis, we aimed at freezing the samples as soon as possible.
So only a few samples were visually inspected and the planktic foraminifera extracted. The
foraminifera assemblage was very diverse as was expected for this region. Among the identified
species were: Hastigerina pelagica, Globigerinella siphonifera, Sphaeroidinella dehiscens,
Trilobatus sacculifer, Globigerinoides ruber, Globigerinoides conglobatus, Globoturborotalita
rubescens, Turborotalita humilis, Neogloboquadrina dutertrei, Globorotalia truncatulinoides,
Globorotalia menardii and Globorotalia scitula.
The available co-registered CTD data show that we sampled three different water masses: the
mixed surface layer, the Subtropical Mode Water (STMW) and the upper part of the Antarctic
Intermediate Water (AAIW) (Fig. 4.34). Maximal chlorophyll concentrations of up to 2 µg/L were
found in a thin a deep chlorophyll maximum below the pycnocline at depths between 60 and
115 m.
Fig. 4.34
TS-diagram of waters sampled with the MPS. (all
available CTD data merged)
Table 4.6 Multi Plankton Sampler sampling stations during cruise M123
Station
GeoB206# Date Latitude Longitude Plankton
samples CTD Water
samples
01-1 5.2.2016 31° 59,78’ S 15° 58,18’ E 5 - -
01-2 5.2.2016 31° 59,78’ S 15° 58,18’ E 5 - -
01-3 5.2.2016 31° 59,78’ S 15° 58,18’ E 2 - -
06-1 11.2.2016 27° 54,71’ S 32° 58,20’ E 5 X 10
06-2 11.2.2016 27° 54,86’ S 32° 58,04’ E 5 X 10
06-3 11.2.2016 27° 54,89’ S 32° 58,02’ E 5 X -
18-1 17.2.2016 29° 02,07’ S 32° 26,74’ E 5 - -
18-2 17.2.2016 29° 03,37’ S 32° 26,03’ E 5 X 10
18-3 17.2.2016 29° 03,83’ S 32° 25,75’ E 5 X 6
20-1 18.2.2016 31° 10,36’ S 32° 08,88’ E 5 X 10
20-2 18.2.2016 31° 10,36’ S 32° 08,88’ E 5 X 10
20-3 18.2.2016 31° 10,36’ S 32° 08,88’ E 5 X -
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 41
Table 4.6 Multi Plankton Sampler sampling stations during cruise M123 (continuation)
Station
GeoB206# Date Latitude Longitude Plankton
samples CTD Water
samples
26-1 22.2.2016 33° 06,48’ S 28° 21,60’ E 5 - 8
26-2 22.2.2016 33° 08,36’ S 28° 18,87’ E 5 - 10
26-3 22.2.2016 33° 08,78’ S 28° 18,12’ E 5 - -
26-4 22.2.2016 33° 10,06’ S 28° 16,63’ E 5 - -
27-1 23.2.2016 34° 26,44’ S 26° 14,98’ E 5 - -
27-2 23.2.2016 34° 28,17’ S 26° 12,19’ E 5 - 10
27-3 23.2.2016 34° 28,66’ S 26° 11,31’ E 4 - 4
4.7 Sampling of Surface Water Suspended Material
(E. Schefuß)
To analyse the distributions of algal lipids and their isotopic signatures, surface water suspended
particulate organic matter was sampled using the vessel's rotary pump. The water was filtered
through pre-combusted glass fibre filters (GF/F, Whatman). After sampling, the filters were
wrapped in pre-combusted aluminium foil and dried at 40°C for several days. To determine the
isotopic fractionation between the surface water and lipids, two 2-ml water samples were taken at
each sampling transect, one at the beginning and one at the end. The water samples were not
poisoned. The water bottles were thoroughly closed with lids and stored at room temperature. The
water samples are numbered according to the filter samples, #-I for the sample taken at the start of
a sample transect and #-II for the sample taken at its end.
Table 4.7 List of suspended particulate organic matter samples. Sea-surface temperature (SST) and salinity
(SSS) are derived from the ship’s thermosalinograph.
No.
Date
Time
Latitude
Longitude
SST
SSS
Volume
(UTC)
deg
min
deg
min
°C
Psu
Liters
1
Start
04.02.16
12:25
27
15.637
S
14
49.327
E
16.440
34.92
69
Stop
12:58
21.085
50.665
16.670
34.92
2
Start
04.02.16
17:13
28
1.178
S
15
0.615
E
20.760
34.82
169
Stop
17:58
7.738
2.229
20.890
34.84
3
Start
05.02.16
6:52
30
13.215
S
15
33.853
E
20.080
34.85
134
Stop
8:25
29.322
37.959
20.490
34.98
4
Start
05.02.16
13:52
31
23.708
S
15
51.908
E
20.800
35.17
152
Stop
15:22
38.780
55.796
19.570
35.15
5
Start
06.02.16
10:42
33
29.583
S
17
10.966
E
21.040
35.28
288
Stop
12:48
45.730
25.668
18.910
35.13
6
Start
06.02.16
17:16
34
17.917
S
17
55.701
E
21.970
35.33
256
Stop
18:42
26.841
18
7.353
22.300
35.32
7
Start
07.02.16
8:31
35
14.689
S
20
14.587
E
22.890
35.43
438
Stop
10:27
12.525
38.351
22.040
35.29
8
Start
07.02.16
17:38
35
5.813
S
22
7.760
E
19.300
34.86
120
Stop
18:12
4.960
14.660
19.030
34.86
9
Start
08.02.16
7:30
34
28.180
S
24
44.807
E
18.790
35.15
130
Stop
9:13
23.478
16.912
18.780
35.06
10
Start
08.02.16
17:12
33
57.482
S
26
34.079
E
19.960
35.25
168
Stop
10:00
54.579
42.581
21.380
35.30
42 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Table 4.7.1 List of suspended particulate organic matter samples. Sea-surface temperature (SST) and salinity
(SSS) are derived from the ship’s thermosalinograph. (continuation)
No.
Date
Time
Latitude
Longitude
SST
SSS
Volume
(UTC)
deg
min
deg
min
°C
Psu
Liters
11
Start
09.02.16
7:32
32
50.922
S
28
20.201
E
24.940
35.24
367
Stop
9:35
42.983
39.139
25.650
35.25
12
Start
09.02.16
16:48
31
52.638
S
29
31.244
E
26.510
35.33
285
Stop
17:27
46.877
34.327
26.240
35.32
13
Start
10.02.16
12:28
29
54.923
S
31
25.411
E
27.700
35.28
441
Stop
13:44
41.177
32.948
27.170
35.27
14
Start
10.02.16
16:58
29
13.887
S
31
42.518
E
25.460
35.23
220
Stop
17:44
12.942
42.506
25.430
35.22
15
Start
11.02.16
9:59
27
54.166
S
33
0.530
E
27.340
35.27
726
Stop
12:56
35.006
26.552
28.080
35.29
16
Start
11.02.16
16:25
27
3.849
S
33
50.143
E
27.800
35.22
518
Stop
17:38
26
52.802
58.476
27.810
35.26
17
Start
12.02.16
11:28
25
28.814
S
35
15.065
E
27.270
35.28
466
Stop
12:37
27.875
20.291
27.420
35.38
18
Start
13.02.16
9:21
25
36.184
S
33
51.699
E
27.730
35.34
584
Stop
11:10
25.514
48.740
27.410
35.34
19
Start
14.02.16
12:12
25
10.997
S
34
9.475
E
27.440
35.31
553
Stop
13:59
12.873
33
47.500
27.650
35.36
20
Start
15.02.16
12:52
25
35.411
S
33
20.114
E
27.530
35.26
542
Stop
14:33
26.512
30.216
27.880
35.38
21
Start
16.02.16
10:52
26
6.724
S
33
40.752
E
27.290
35.32
488
Stop
12:18
21.672
35.306
27.000
35.36
22
Start
17.02.16
11:08
29
29.385
S
31
44.867
E
22.990
35.26
278
Stop
12:17
24.601
40.772
23.260
35.21
23
Start
17.02.16
14:48
29
13.628
S
31
34.102
E
24.700
35.24
92
Stop
15:48
10.861
39.642
24.690
35.25
24
Start
18.02.16
9:31
31
10.713
S
32
8.010
E
26.470
35.15
704
Stop
11:23
10.360
8.907
26.480
35.16
25
Start
19.02.16
12:20
30
2.846
S
31
15.614
E
24.050
35.20
293
Stop
13:27
14.529
3.678
24.720
35.20
26
Start
20.02.16
11:10
31
44.382
S
29
41.110
E
24.940
35.23
472
Stop
12:40
39.355
48.169
24.140
35.21
27
Start
21.02.16
13:58
31
52.034
S
29
52.263
E
24.980
35.26
298
Stop
15:03
52.032
52.263
25.050
35.26
28
Start
22.02.16
13:48
32
53.981
S
28
14.719
E
24.280
35.22
333
Stop
15:00
33
4.880
20.584
25.580
35.22
29
Start
23.02.16
9:20
34
22.919
S
25
25.253
E
20.970
35.18
171
Stop
10:04
21.196
15.178
21.120
35.20
30
Start
24.02.16
10:21
34
33.996
S
21
5.482
E
21.730
35.09
217
Stop
11:15
39.885
20
58.078
21.550
35.08
(Base on the continuously sampling, these samples got neither a station number nor a GeoB number)
4.8 Water Sampling
(M. Humphries, K. Strachan)
Surface water samples for radium isotope analysis (226Ra and 228Ra) were collected at 15 sites
along the South African coast (Tab. 4.8). Sampling focused specifically on the western and
southern margins of the country in order to compliment data already obtained from the east coast.
Samples were recovered using the vessel’s seawater line and therefore did not require any station
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 43
time. At each sampling station, 210 L of seawater was collected and then pumped through an
acrylic MnO2 fibre at a flow rate of <1 L min-1. Fibre samples were then bagged and stored for
analysis.
Table 4.8 Radium isotope water sampling locations
Sample ID
Date of collection
Time filtering
stopped
Latitude
Longitude
Remark
M123-1
05/02/2016
15:20
30o 11.9 S
15o 33.5 E
West coast
M123-2
05/02/2016
21:32
31o 20.14 S
15o 50.98 E
West coast
M123-3
06/02/2016
09:20
32o 06.70 S
15o 52.10 E
West coast
M123-4
06/02/2016
14:10
33o 08.25 S
16o 51.58 E
West coast, Saldanha Bay
M123-5
06/02/2016
22:10
34o 06.99 S
17o 45.08 E
West coast, Cape Town
M123-6
13/02/2016
13:30
24o 54.30 S
34o 48.38 E
Maputo Bay
M123-7
14/02/2016
07:00
25o 11.405 S
33o 45.27 E
Maputo Bay
M123-8
15/02/2016
14:15
25o 33.85 S
33o 03.998 E
Maputo Bay
M123-9
22/02/2016
19:46
32o 49.53 S
28o 10.11 E
South coast, EL
M123-10
23/02/2016
18:35
34o 18.797 S
25o 01.157 E
South coast, St Francis Bay
M123-11
24/02/2016
06:25
34o 12.886 S
23o 52.578 E
South coast, Plettenberg Bay
M123-12
24/02/2016
10:31
34o 28.871 S
21o 40.722 E
South coast, Still Bay
M123-13
25/02/2016
16:00
34o 05.700 S
22o 36.008 E
South coast, Wilderness
M123-14
26/02/2016
14:10
35o 05.454 S
19o 58.791 E
South coast, Cape Agulhas
M123-15
26/02/2016
21:02
34o 46.681 S
19o 02.699 E
South coast, Danger Point
(Base on the continuously sampling, these samples got neither a station number nor a GeoB number)
5 Ship’s Meteorological Station
(C. Rohleder, M. Stelzner)
On the 3th of February about nine o’clock local time R/V METEOR left the harbor of Walvis
Bay/Namibia to this expedition. At this time a trough extended over the coast of southwestern
Africa from the tropical low-pressure area to south. Between low pressure on the African
continent and the slowly reinforcing and shifting southeast anticyclone above the South
Atlantic it came on the first night of the journey to strong southerly winds to
6 Beaufort. The significant wave height increased until the morning of the second day to 3,5 m. On
Friday, the 5th of February, RV Meteor reached the first working station of this trip. At low
pressure influence the weather conditions were ideal with
southern wind at Beaufort 4 and a significant wave height of 1.5 to 2 m.
For the onward journey to the Cape of Good Hope a cyclone from the west was forecasted, its
front finally reached the Cape in the night to Sunday. In the evening of 6th of February RV Meteor
passed the Table Mountain and the Cape of Good Hope in good weather conditions. The
storm reached the ship not until the following night. At the same time drew a cyclone drew east of
Mozambique to the south. Overall, cool and unstable air flowed in the sailing area, which
accompanied the weather until the second week of the expedition. Passing Cape Agulhas,
RV Meteor left the Atlantic Ocean and arrived at the Indian Ocean. Some rain showers, significant
wave heights from 2 to 3 m and wind speeds in the range of 5–6 Beaufort dominated the next few
days of the transit to the first working area.
Around the 9th of February R/V METEOR arrived in the area of the Agulhas Current. This
ocean current along the east coast of Africa is transporting huge amounts of warm water to the
44 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
south. This caused air temperatures above the 25°C mark for the followed days of this leg. R/V
METEOR arrived at the first working area on the mouth of the river Limpopo in Mozambique on
12th of February. When the station work began, there were weak winds from south, caused by low
pressure opposites. Similar weather conditions prevailed also for the rest of the days until the
end of the research on the coast of Mozambique.
On Tuesday, the 16th of February, R/V METEOR left the first working area. A trough of low
pressure along the southwest African coast caused weak wind from variable directions on the sail
to south. Meantime the working area 2 came under the influence of a wedge of a high, which
moved from west over the coast of South Africa. This wedge shifted slowly to south. At the same
time a new area of low pressure formed over the south of South Africa. Thereby the air pressure
differences were increased. The wind freshened appreciably. The morning of the 18th of February
was marked by sometimes heavy rain. The amount of precipitation during this rain period was
circa 110 liters/square meter. The station work was nevertheless continued. In the
afternoon calmed down the weather.
At 18th of February, it was decided, to repeat a working station about 100 nm to northeast.
Therefore, the ship sailed that afternoon in this direction. On this path R/V METEOR crossed a
thunderstorm area, which, starting from the said low pressure area, spread out of the coastal area.
In the early evening lightning was observed, short time later the ship was in a strong, widely
extended thunderstorm cell, which further moved in the late night to the
southeast. Strong gusts (highest wind speed 16.7 m/s) and waves prevented the sail of the ship.
The working station was reached on the next morning and could be finished with a clear
sky and best working conditions after deduction of thunderstorm cell.
On the way back to the primary route, the weather was sunny with northeasterly winds about 4
Beaufort and a swell about 1.5 to 2 m. The low on the South African coast strengthened during the
day on its southern side, moved slowly southeastward and caused rain showers and thunderstorms
again. During the first use of the vibrocorer in the evening of the 19th of February lightning could
be observed in the coastal areas. Unfortunately, technical problems delayed the recovery of the
device and a thunderstorm reached the R/V METEOR before the work was completed. With wind
about 7 Beaufort, increased waves and moderate rain showers, the problem had to be
solved despite strong lightning activity, which ultimately succeeded.
In the further course of the sail a new wedge of a high moved slowly from west into the working
area. Later this wedge became a high pressure center in the east of the working area. On 20th of
February there was a significant wave high around 4 m, the wind blew with 8 Beaufort and there
have been occasional rain showers. On Sunday, 21th of February, the weather conditions calmed
noticeably. An eastward shifting polar low pressure zone with several low pressure centers south of
the Cape of Good Hope influenced the last working area only on Tuesday, the 23th of February
with increasing swell around 3m. On Thursday, 25th of February the last station could be finished
in good weather conditions.
In the morning of 26th of February R/V METEOR passed the Cape of Good Hope again. A trail
of a cyclone which was passing the southern point of Africa on Friday, caused wind with 7–
8 Beaufort and a significant wave high around 3m again.
In the morning of the 27th of February R/V METEOR arrived at Cape Town.
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 45
6 Station List M123
(M. Zabel, A. Hahn)
Table 6.1 Station list M123
Station Nr GeoB Gear* Date Time Lat
(S) Long
( E) Water Depth
(m) Recovery
(cm)
M123_160-1 20601-1 MPS-700 05.02.16 22:45:00 31°59.780' 15°58.180' 874
M123_160-2 20601-2 MPS-100 05.02.16 22:45:00 31°59.783' 15°58.184' 874
M123_160-3 20601-3 MPS-500 05.02.16 22:45:00 31°59.783' 15°58.184' 874
M123_160-4 20601-4 GC-12 05.02.16 22:45:00 31°59.783' 15°58.184' 874 868
M123_161-1 20602-1 BC 08.02.16 16:45:00 34° 2.241' 26°20.301' 117
M123_162-1 20603-1 BC 09.02.16 06:45:00 32°51.971' 28°15.987' 75
M123_163-1 20604-1 BC 09.02.16 19:13:00 31°42.310' 29°38.040' 668
M123_164-1 20605-1 BC 10.02.16 19:46:00 29°11.506' 31°41.452' 69
M123_165-1 20606-1 MPS-700 11.02.16 08:00:00 27°54.863' 32°58.039' 1227
M123_165-2 20606-2 MPS-100 11.02.16 08:00:00 27°54.863' 32°58.039' 1227
M123_165-3 20606-3 MPS-500 11.02.16 08:00:00 27°54.863' 32°58.039' 1227
M123_166-1 20607-1 MC 12.02.16 02:00:00 25°49.262' 34°46.153' 485
M123_166-2 20607-2 GC-12 12.02.16 02:00:00 25°49.262' 34°46.153' 485 870
M123_167-1 20608-1 GC-12 12.02.16 06:00:00 25°36.711' 34°43.320' 286 273**
M123_167-2 20608-2 MC 12.02.16 06:00:00 25°36.711' 34°43.320' 286
M123_168-1 20609-1 MC 12.02.16 14:31:00 25°31.658' 35° 3.590' 461
M123_168-2 20609-2 GC-12 12.02.16 14:33:00 25°31.658' 35° 3.590' 461 831
M123_169-1 20610-1 BC 14.02.16 08:00:00 25° 2.696' 34°43.543' 59
M123_169-2 20610-2 GC-6 14.02.16 08:00:00 25° 2.696' 34°43.543' 59 321
M123_170-1 20611-1 BC 14.02.16 08:33:00 25° 8.352' 34°40.300' 120
M123_170-2 20611-2 GC-6 14.02.16 08:33:00 25° 8.352' 34°40.300' 120 empty
M123_171-1 20612-1 BC 14.02.16 17:30:00 25°14.233' 33°45.880' 88
M123_172-1 20613-1 BC 14.02.16 18:00:00 25°45.451' 33°54.289' 424
M123_172-2 20613-2 GC-6 14.02.16 18:00:00 25°45.451' 33°54.289' 424 463
M123_173-1 20614-1 BC 15.02.16 09:10:00 25°32.489' 33°10.135' 51
M123_174-1 20615-1 BC 15.02.16 11:04:00 25°33.073' 33°12.181' 200
M123_174-2 20615-2 GC-6 15.02.16 11:04:00 25°33.073' 33°12.181' 200 532
M123_175-1 20616-1 GC-12 15.02.16 13:00:00 25°35.395' 33°20.084' 460 957
M123_176-1 20617-1 GC-12 16.02.16 08:00:00 25°36.442' 33°51.795' 430 862
M123_177-1 20618-1 MPS-700 17.02.16 04:30:00 29°03.330' 32°26.070' 1290
M123_177-2 20618-2 MPS-100 17.02.16 04:30:00 29°03.330' 32°26.070' 1272
M123_177-3 20618-3 MPS-500 17.02.16 04:30:00 29°03.330' 32°26.070' 1290
M123_178-1 20619-1 BC 17.02.16 18:30:00 29°15.965' 31°33.525' 32
M123_178-2 20619-2 GC-6 17.02.16 18:30:00 29°15.965' 31°33.525' 32 600
M123_178-3 20619-3 GC-12 17.02.16 18:30:00 29°15.965' 31°33.525' 32 826
M123_179-1 20620-1 MPS-700 18.02.16 08:30:00 31°10.459' 32°08.637' 3059
M123_179-2 20620-2 MPS-100 18.02.16 08:30:00 31°10.459' 32°08.637' 3059
M123_179-3 20620-3 MPS-500 18.02.16 10:30:00 31°10.459' 32°08.637' 3059
M123_179-4 20620-4 GC-12 18.02.16 12:30:00 31°10.459' 32°08.637' 3059 387**
M123_179-5 20620-5 BC 18.02.16 13:30:00 31°10.459' 32°08.637' 3059
46 METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016
Table 6.1 Station list M123 (continuation)
Station Nr GeoB Gear* Date Time Lat
(S) Long
( E) Water Depth
(m) Recovery
(cm)
M123_180-1 20621-1 GC-12 19.02.16 07:24:00 29°15.981' 31°33.490' 34 717
M123_181-1 20622-1 BC 19.02.16 18:40:00 30°45.301' 30°35.520' 85
M123_181-2 20622-2 VC 19.02.16 18:40:00 30°45.301' 30°35.520' 85 399
M123_182-1 20623-1 GC-6 21.02.16 10:45:00 31°42.294' 29°38.034' 671 316
M123_183-1 20624-1 GC-6 21.02.16 13:32:00 31°52.034' 29°52.273' 2644 600
M123_183-2 20624-2 BC 21.02.16 14:32:00 31°52.034' 29°52.273' 2643
M123_184-1 20625-1 BC 22.02.16 12:10:00 32°49.530' 28°20.110' 37
M123_185-1 20626-1 MPS-700 24.02.16 16:00:00 33°06.480' 28°21.060' 1259
M123_185-2 20626-2 MPS-100 24.02.16 16:00:00 33°06.480' 28°21.060' 1259
M123_185-3 20626-3 MPS-500 24.02.16 16:00:00 33°06.480' 28°21.060' 1259
M123_185-4 20626-4 MPS-500 24.02.16 16:00:00 33°06.480' 28°21.060' 1259
M123_186-1 20627-1 MPS-700 24.02.16 05:32:00 34°29.690' 26°11.310' 1267
M123_186-2 20627-2 MPS-100 24.02.16 05:32:00 34°29.690' 26°11.310' 1267
M123_186-3 20627-3 MPS-500 24.02.16 05:32:00 34°29.690' 26°11.310' 1267
M123_187-1 20628-1 VC 24.02.16 10:30:00 34°33.880' 21°05.670' 71 436
M123_188-1 20629-1 VC 25.02.16 06:43:00 34°05.605' 22°35.993' 50 499
* gear types: BC box corer, GC gravity corer, MC multicorer, MPS multi plankton sampler, VC vibrocorer
** bent core barrel (“banana”)
7 Data and Sample Storage and Availability
All metadata were delivered to the PANGAEA World Data Center MARE and to the BSH (CSR)
immediately after the cruise. The ship station list is published together with the SCR on the
homepage of the control station METEOR. Geological cores are stored in the MARUM core
repository. These and the other geological samples have obtained GeoB ID numbers in addition to
the PANGAEA event labels. All analytical data, which will be gained from cruise samples will
also be delivered to the PANGAEA WDC MARE.
Type Database Available Free Access Contact
hydrography March 2016 March 2016
raw data / CTD PANGAEA March 2016 March 2016 lgerullis@marum.de
analytical data PANGAEA As soon as they
were gained July 2018 mzabel@marum.de
Cores / Samples May 2016 June 2019 mzabel@marum.de
8 Acknowledgements
The overall successful course of this expedition needs to be attributed to the friendly cooperation
and very efficient technical assistance of Captain Michael Schneider, his officers and crew. No
matter in which area, we always were attentively cared for. It was always obvious that all people
on board worked on a common task. For this we would like to thank everybody involved, last but
not least also the Leitstelle METEOR Hamburg. We would like to cordially thank Götz Ruhland
METEOR-Berichte, Cruise M123, Walvis Bay Cape Town, 03.02. – 27.02.2016 47
(MARUM/Bremen University), Klaus Bohn (LPL Projects + Logistics GmbH) and their teams for
professional support of expedition logistics.
The expedition was funded by the Federal Ministry of Education and Research (BMBF;
03F0731A) and strongly supported by MARUM.
9 References
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composition of surficial sediments of the continental margin of the Republics of South Africa,
Transkei and Ciskei. 1 pp.
Boyce, R.E., 1968. Electrical resistivity of modern marine sediments from the Bering Sea. J.
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Cawthra, H.C., 2014. The marine geology of Mossel Bay. Ph.D. Thesis, University of Cape Town,
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Garzanti, E., Vermeesch, P., Padoan, M., Resentini, A., Vezzoli, G., Andò, S., 2014. Provenance
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