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Ammonite findings from Byers Peninsula, Livingston Island, Antarctica

Conference Paper (PDF Available)  · December 2016with100 Reads

Conference: Conference: Geosciences, 2016
Docho Dochev at Sofia University "St. Kliment Ohridski"
  • 5.01
  • Sofia University "St. Kliment Ohridski"
Marin Ivanov Ivanov at Sofia University "St. Kliment Ohridski"
  • 19.33
  • Sofia University "St. Kliment Ohridski"
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БЪЛГАРСКО ГЕОЛОГИЧЕСКО ДРУЖЕСТВО, Национална конференция с международно участие „ГЕОНАУКИ 2016“
BULGARIAN GEOLOGICAL SOCIETY, National Conference with international participation “GEOSCIENCES 2016”
Ammonite findings from Byers Peninsula, Livingston Island, Antarctica
Амонитни находки от п-в Байърс, о-в Ливингстън, Антарктика
Docho Dochev1, Viara Idakieva1, Marin Ivanov1, Stefan Velev1, Kamen Bonev2
Дочо Дочев1, Вяра Идакиева1, Марин Иванов1, Стефан Велев1, Камен Бонев2
1 Sofia University “St. Kliment Ohridski”, Faculty of Geology and Geography, 15 Tzar Osvoboditel Blvd., 1504 Sofia;
E-mails: dochev@gea.uni-sofia.bg; idkieva@gea.uni-sofia.bg; mivanov@gea.uni-sofia.bg; velev@gea.uni-sofia.bg
2 Bulgarian Antarctic Institute, 15 Tzar Osvoboditel Blvd., 1504 Sofia; E-mail: bonev.kamen@gmail.com
Keywords: ammonites, Upper Tithonian–Berriasian, Devils Point Formation, President Beaches Formation,
Byers Peninsula, Antarctica.
Byers Peninsula is the largest ice-free area of Liv-
ingston Island, South Shetland Islands, Antarctica.
Exposed Upper Jurassic–Lower Cretaceous sedimen-
tary and volcanic rocks are included in Byers Group,
which is composed of formal lithostratigraphic units.
According to Crame et al. (1993) sedimentary and
volcanic successions are grouped into 4 formations
as follows: Anchorage Formation (Kimmeridgian–
Tithonian), Devils Point Formation (Berriassian),
President Beaches Formation (Berriasian) and Chester
Cone Formation (Valanginian). Afterward Hathaway
and Lomas (1998) revised the lithostratigraphical
scheme of Crame et at. (1993) and proposed some new
formal lithostratigraphic units: Anchorage Formation
(Kimmeridgian–Tithonian), President Beaches Forma-
tion and Start Hill Formation (Berriasian), Chester
Cone Formation (with Devils Point Member and Sealer
Hill Member) (?Upper Berriasian to Valanginian) and
Cerro Negro Formation (Aptian).
During the field season in 2016 we found a rel-
atively abundant ammonite fauna in the SW part of
Byers Peninsula at the vicinity of Devils Point and
President Beaches areas (Fig. 1). Ammonite specimens
from Devils Point area were collected from mid, dark-
grey mudstones intercalated between coarse-grained
sandstones beds. Mudstone-dominated sequences
and coarse-grained clastic rocks, cropping out in the
Devils Point area, are part of Devils Point Formation
(Berriasian) according to Crame et al. (1993). Later
Hathaway and Lomas (1998) include this sequence at
the base of Chester Cone Formation as Devils Point
Member (?Upper Berriasian).
More abundant ammonite fauna was obtained
from very coarse-grain, green sandstones in the
south western part of President Beaches area (Fig. 1).
Sedimentary rocks exposed in the most western part
of the Peninsula (including our locality) are composed
mainly of mudstones and small sandstone bodies,
which were combined in President Beaches Formation
(Berriasian). These formal units are the most fossil-
iferous part of Byers Group. The obtained ammonite
fauna have already been subject of investigation from
Chilean paleontologists and subsequently listed by
Smellie et al. (1980). Based mainly on ammonite taxa
(obtained from different localities at the Peninsula) the
age of Byers Group was determined as Kimmeridgian
to Valanginian.
In the locality in Devils Point area we recog-
nized Haplophylloceras strigile (Blanford, 1864) and
Protancyloceras sp. indet. The first one is known from
the Indo-Pacific and Antarctic Realms. It is character-
istic species for the Uppermost Tithonian and/or for
the base of the Berriasian (Thompson, 1979; Yin,
Enay, 2004). We consider that the ammonite findings
from Devils Point Fm indicate Latest Tithonian–Early
Berriasian age.
The following ammonite taxa were identified
in the locality of President Beaches area: Spiticeras
(Spiticeras) spitiensis (Blanford, 1864), S. biloba-
tum (Uhlig, 1903), ?Spiticeras tripartitum lovalde-
sensis Biro-Bagoczky, 1980 and Argentiniceras lon-
chochense (Steuer, 1897). Traditionally, the represent-
atives of genus Argentiniceras have been often report-
ed from the Lower Berriasian of Argentina and Chile,
as well from Alexander Island, Antarctica. Rare find-
ings are known from India and Yemen. Argentiniceras
noduliferum is used as an index-species of zone, which
quite recently had been positioned at the base of the
Berriasian of Argentina and Chile (Aguirre-Urreta et
al., 2007). Lately, the range of this zone was revised,
corresponding to S. occitanica Zone and partly to the
S. boissieri Zone from the Standard Mediterranean
112
Zonal scheme (Riccardi, 2015). Argentiniceras lon-
chochense is a characteristic element of the ammonite
association of the Argentiniceras noduliferum Zone.
Genus Spiticeras has a wide geographical distribution
and its range passes through the Jurassic/Cretaceous
boundary. However, its major abundance was reported
from Berriasian, including Antarctic area (Thompson,
1979). Spiticeras damesi was served as a zonal in-
dex for the Upper Berriasian of the Andean basins
and corresponds to S. boissieri Zone in the Tethyan
Mediterranean zonation (Aguirre-Urreta et al., 2007).
This species is considered by some authors to be a
synonym of Spiticeras tripartitum and it has the same
range. Based on newly collected ammonite fauna
we suggest Upper Berriasain age of this interval of
President Beaches Formation.
The biostratigraphic interpretation of the newly
collected fauna from the two localities allowed us
to establish Upper Tithonian–Lower Berriasian age
for Devils Point Fm and ?Upper Berriasian age for
President Beaches Fm. Thus, the specified age gave
us a reason to conclude that the Devils Point Fm has
position below the President Beach Fm in accordance
with the scheme of Crame et al. (1993).
References
Aguirre-Urreta, M. B., F. A. Mourgues, P. F. Rawson, L. G.
Bulot, E. Jaillard. 2007. The Lower Cretaceous Chañarcillo
and Neuquén Andean basins: ammonoid biostratigraphy
and correlations. – Geol. J., 42, 143–173.
Crame, J. A., D. Pirrie, J. S. Crampton, A. M. Duane. 1993.
Stratigraphy and regional significance of the Upper
Jurassic–Lower Cretaceous Byers Group, Livingston Is-
land, Antarctica. – J. Geol. Soc. London, 150, 1075–1087.
Hathaway, B., S. A. Lomas. 1998. The Upper Jurassic–
Lower Cretaceous Byers Group, South Shetland Islands,
Antarctica: revised stratigraphy and regional correlations.
Cretaceous Res., 19, 43–67.
Riccardi, A. 2015. Remarks on the Tithonian–Berriasian ammo-
nite biostratigraphy of west central Argentina. Volumina
Jurassica, 13, 2, 23–52.
Smellie, J. L., R. E. S. Davies, M. R. A. Thomson. 1980.
Geology of a Mesozoic intra-arc sequence of Byers
Peninsula, Livingston Island, South Shetland Islands. –
British Antarctic Survey Reports, 50, 55–76.
Thomson, M. R. A. 1979. Upper Jurassic and Lower Creta-
ceous Ammonite Faunas of the Ablation Point Area,
Alexander Island. Cambridge, British Antarctic Survey
Scientific Reports, 97, 37 p.
Yin, J., R. Enay. 2004. Tithonian ammonoid biostratigraphy in
eastern Himalayan Tibet. – Geobios, 37, 667–686.
Fig. 1. Locality map of the Antarctic Peninsula Region. A, locality map of the Antarctic Peninsula, Scotia Arc and southernmost South America;
B, locality map of South Shetland Islands and the position of Livingston Island; C, position of Byers Peninsula at the western extremity of
Livingston Island (after Crame et al., 1993)

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