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Recent New Zealand deep-water benthic foraminifera, taxonomy, ecologic distribution, biogeography, and use in paleoenvironmental assessment

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Abstract

Taxonomy A total of 563 species is listed from deep water (>50 m) from the New Zealand Exclusive Economic Zone (EEZ). The 347 most common or distinctive species are fully illustrated and their diagnostic features outlined. Two new species are described: Ammoscalaria georgescotti n. sp. and Spiroplectammina carteri n. sp. When used in combination with our twin publication on New Zealand’s shallow-water benthic foraminifera (Hayward et al. 1999), these two bulletins provide descriptive data and illustrations of the 504 most common and distinctive benthic foraminifera living in New Zealand marine and brackish environments. Ecologic distribution of deep-water foraminifera We use census counts (59,000 specimens) of 424 species in 264 samples to map the distribution of deep-sea (50-5000 m depth) benthic foraminifera around New Zealand. Using Q mode cluster analysis (chord similarity coefficient) of the full census data we identify 7 high-level ecologic associations (A-G), 6 of which can be further subdivided into 32 subassociations. The deepest association (A), dominated by Nuttallides umbonifera and Globocassidulina subglobosa occurs at mid-lower abyssal depths (>3500 m) east of New Zealand. The next deepest, C (Epistominella exigua - Alabaminella weddellensis), is widespread at lower bathyal – abyssal depths (>1200 m) off both sides of central and northern New Zealand, but does not extend into the subantarctic zone. Three bathyal associations are recognised, with D and E occurring right around New Zealand and B restricted to the subantarctic. Association D (Cassidulina carinata – A. weddellensis) is usually in deeper, less current-swept waters than E (Globocassidulina canalisuturata – Bolivina robusta). Association B (Trifarina angulosa – Ehrenbergina glabra) also occurs in deeper parts of the bathyal zone (900-2000 m) along the strong current-swept, south-eastern margin of the Campbell and Bounty Plateaux, beneath the Subantarctic Front. Associations F (Cassidulina carinata – Trifarina angulosa) and G (Cassidulina carinata – Bulimina marginata f. marginata) mostly occur at mid shelf-upper bathyal depths (50-600 m) around southern and northern New Zealand respectively, with the dividing line approximating the position of the Subtropical Front. Q mode cluster analysis (Jaccard coefficient) of presence/absence data of the 424 species in the 264 samples allows the recognition of nine high-level associations (a-i), four of which are further subdivided into 13 subassociations. The distribution of these associations is similar, but not identical, to that based on the quantitative data, indicating that total species composition is just as important as the relative abundance of dominant species in defining these regions. R-mode cluster analysis (Pearson product-moment correlation coefficient) of full census data for the 56 most common species allows the recognition of eight groups, whose distribution is most strongly linked to bathymetry and secondly to geography. Two abyssal-lower bathyal associations (dominated by Globocassidulina subglobosa and Trifarina angulosa) are most abundant off southern New Zealand; one from lower bathyal-abyssal depths (Epistominella exigua) occurs dominantly east of northern and central New Zealand; an outer shelf to mid bathyal association (Cassidulina carinata) is more common to the east and south than the west; and another from mid-lower bathyal depths (Uvigerina peregrina) dominantly occurs off the west coast of New Zealand. The remaining three are common all around New Zealand. Canonical correspondence analysis was used to relate sample associations to a set of environmental "drivers" using the full census data. Bathyal and abyssal associations appear to be more strongly influenced by depth-related variables (e.g., bottom temperature, salinity, oxygen, carbon flux) and shallower associations by latitude-related differences in surface-water characteristics (e.g., temperature, surface phosphate, chlorophyll-a). Environmental variables that influence faunal patterns at abyssal and lower bathyal depths (Assocs. A-C) appear to be, in decreasing order: bottom current strength (mud percentage proxy), carbonate corrosiveness (fragmentation index and planktic % proxies), quality, quantity and seasonality of organic carbon flux to the sea floor (surface phosphate, sea surface temperature, spring and summer chlorophyll-a proxies), and possibly properties of bottom water masses (salinity proxy). Faunal patterns within bathyal associations (D, E) are most strongly influenced by organic carbon flux (surface phosphate proxy), bottom oxygen concentrations (bottom water measurements) and bottom current strength (mud percentage proxy). Latitude-related variables driving mid shelf-upper bathyal faunal patterns (Assocs. F, G) include water temperature and primary productivity in the overlying waters (chlorophyll-a and organic carbon flux proxies). Species diversity Based on calculations for individual samples, the species diversity (α, H) of New Zealand benthic foraminiferal faunas overall and at all depths down to mid abyssal (<3000 m) decreases from lower to higher latitudes. At lower abyssal depths (>3000 m) faunas from all regions have a similar range of species diversity. There are no consistent diversity or evenness trends related to depth. Faunal evenness (E) decreases from north to south around New Zealand with more dominance of opportunistic species in the south where nutrients and food supply are more seasonally pulsed. Based on SHE analysis for biofacies identification (SHEBI), 16 communities were identified in the deep sea around New Zealand. The communities exhibit a north to south latitudinal trend with lnS, H and lnE decreasing to the south. In the north and in the south the communities show an increase in lnS and H with depth. There is no trend with depth in the east and west areas. The community structure in each community was compared using the log series as a null model. Each area exhibits a unique pattern of community structure. In the north-east, 4 communities are recognised and only one at mid-bathyal depths does not resemble a log series. In the west, 3 communities are identified and only the outer shelf does not resemble a log series. The east is very different, where 4 out of 5 communities do not resemble a log series with only the community at abyssal depths doing so. In the south, all 4 of the recognised communities resemble a log series. All abyssal communities resemble a log series and 5 of 6 communities deeper than 1300 m resemble a log series. The log series is characterised by a constant H and is interpreted as representing community stability. Frequency of species occurrence We found that the pattern of species occurrence in deep water and throughout New Zealand localities approximates a typical log series plot. As a consequence the vast majority of species occur rarely (37% of species occur in <2% of localities) and only a small number occur widely (4% occur in >50% of localities). Buliminid and rotaliid species and those that dominantly live in shallow water have the highest frequency of occurrence and carterinid, astrorhizid, lituolid, trochamminid and robertinid species the lowest occurrence frequency. Species duration We used the recorded regional stratigraphic ranges of 642 modern New Zealand species (both deep, shallow and brackish) to investigate species duration patterns. The percentage of extant species in each of the following orders having a New Zealand fossil record are: Carterinida 0%, Trochamminida 0%, Lituolida 5%, Astrorhizida 10%, Robertinida 20%, Spirillinida 22%, Textulariida 30%, Miliolida 36%, Lagenida 45%, Rotaliida 53%, and Buliminida 59%. Foraminifera that live dominantly in normal marine salinity, shallow (< 100 m) and deep (> 100 m) water have a similar proportion of species recorded fossil from New Zealand (38-42%), with a much lower proportion from brackish environments (11%), reflecting the poor fossil record from brackish settings. Of the 249 extant species with recorded fossil ranges in New Zealand: 3% first appeared in the Cretaceous, 1% in Paleocene, 10% in Eocene, 16% in Oligocene, 47% in Miocene, 14% in Pliocene and 9% in Pleistocene. These species have a mean partial species duration of 20 million years, comparable with a mean of 21 myrs for benthic foraminifera from the Atlantic margin of north America. There is no major difference in the timings of first appearances nor mean partial species durations between deep- and shallow-water-dwelling species. Eighty-one percent of commonly occurring species (in >25% of localities) have a fossil record (mean species duration 21 myrs) compared with 14% of rarely occurring species (mean species duration 24 myrs). Sixty percent of endemic species (mean species duration 13 myrs) have a New Zealand fossil record compared with 43% of cosmopolitan species (mean species duration in NZ of 24 myrs) – the reverse of North American Atlantic coast data. This indicates that endemic species have been more common in New Zealand waters than in the North Atlantic, possibly a reflection of New Zealand’s isolation. Biogeography Sixty-four percent of the 642 extant New Zealand benthic foraminiferal species (both deep, shallow and brackish) have a cosmopolitan distribution, compared with 9% (52 spp) endemic to New Zealand and a further 8% to each of the South-west Pacific (including Australia), West Pacific and Pacific regions. A slightly greater proportion of deep-water (>100 m) species (69%) have a cosmopolitan distribution than do shallower-water (<100 m) species (55%), with brackish species (92%) having the highest proportion. Just 3% of deep-water species (Sigmoilopsis finlayi, Siphonaperta crassa, Spiroloculina novozelandica, Ruakituria pseudorobusta, Jullienella zealandica) are endemic to New Zealand, but 16% of shallow-water species are. Our analyses of species presence/absence data suggest that the benthic foraminiferal biogeography around New Zealand differs at different depths and in different water masses. Five provinces can be recognised in our shallowest faunas (inner-mid shelf) and these correspond well with those identified from molluscs. At mid-outer shelf and upper bathyal depths, only 2 provinces can be identified. With increasing depth, greater subdivision is again possible, with 3 provinces recognisable at mid-lower bathyal depths and 4 at abyssal depths. Twenty-four percent (mostly common species) of all 424 species in our quantitative deep-water data set occur in all four regions - north, west, east and south of New Zealand - 17% are restricted to the north, 16% to the east, 8% to the south and just 4% to the west. The main faunal differences between regions are in the numerous rarely occurring species. Paleoenvironmental assessment There are many environmental drivers of the modern ecologic distribution of foraminifera and these vary from place to place. In this and previous shallow-water studies of modern foraminifera we have been able to correlate the strength of some of these environmental variables with the relative abundance of various taxa or associations. These correlations can be used to provide estimates of the paleoenvironments in which fossil foraminiferal faunas accumulated that are of value to geological, paleoclimatic and paleoceanographic studies. This uniformitarian approach is most applicable to Quaternary and Neogene faunas but far less reliable further back in time in the Paleogene and Cretaceous. Planktic foraminiferal percentages and the relative abundance of different planktic species (census counts) can be used to estimate oceanicity, paleo-sea surface temperature and to give an indication of water depth. The composition of benthic foraminiferal faunas by order may provide a general indication of the past environment, but the relative abundance of benthic genera or species and the recognition of faunal associations allow more detailed environmental assessments. In the deep sea these are predominantly of water depth, seasonal or sustained carbon flux, strong bottom currents, bottom oxygen concentrations or exposure to carbonate corrosive bottom waters. In shallow or brackish environments these are predominantly water depth, tidal elevation, salinity, water temperature and exposure to water turbulence. Although depth is not a driver of foraminiferal distribution, a number of environmental variables show general trends with respect to depth, which allow depth estimates to be extracted from faunal composition data. Charts and tables summarising the depth distribution around New Zealand of a number of genera and species are provided to assist in paleodepth assessments. At bathyal depths we have identified c.60 benthic genera and species that appear to have distinct upper depth limits to their distribution and these provide an additional method to help refine paleodepth estimates of Neogene deep-sea faunas. A method for rapid paleoenvironmental assessments of fossil New Zealand Neogene faunas is outlined, based on a quick estimate of planktic foraminiferal percentage, benthic foraminiferal composition and identification of dominant benthic taxa.
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... Examination of the few samples with well-preserved macro-fossils provided complementary information to that derived from foraminifera. All biostratigraphic ages are reported in terms of the New Zealand Geological Timescale (Cooper 2004;Raine et al. 2015), and paleoenvironmental interpretations are based on Hayward (1986), Hayward et al. (1999Hayward et al. ( , 2010Hayward et al. ( , 2012, Morkhoven et al. (1986), and Hayton et al. (1995). ...
... Hayward et al. (2012) report few records of Stilostomella above 900 m, deep middle bathyal water depths. The P83197 planktic abundance of 40% indicates outer neritic water conditions (Hayward et al. 2010). In sample P83338 (Pleistocene), the majority of the benthic foraminiferal assemblage (Reussella, Bolivinella, Elphidium, Heronallenia, Ehrenbergina, and Karreria) likely represent middle shelf depths (50-100 m), although there is some evidence for bathyal paleodepths of 200 m or deeper indicated by Pullenia and Stilostomella (Hayward 1986;Hayward et al. 2012). ...
... The presence of Buliminella browni and Nuttallides truempyi in sample P83331 (early Eocene), indicate upper bathyal water depths or deeper (Hayward 1986). Benthic foraminifera in sample P83325 (middle Eocene) include Vulvulina bortonica, Stilostomella, Pleurostomella and Karreriella spp., which are species typical of deep middle bathyal water depths 800-1000 m (Hayward 1986;Hayward et al. 2010Hayward et al. , 2012. Similar water depths are indicated for samples P83257 (Vulvulina pennatula, Pleurostomella brevis, and Gyroidinoides neosoldanii) and P83253 (Vulvulina pennatula, Pleurostomella alternans, and Stilostomella sp.). ...
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... Species identification and palaeoenvironmental interpretation were based on classic and modern literature both for benthic foraminifers (i.a. Sen Gupta et al., 2009a;Hayward et al., 2010;Debenay, 2012;Milker and Schmiedl, 2012;Aiello et al., 2018) and, with special regard to the Mediterranean area, for ostracods (i.a. Bonaduce et al., 1976;Breman, 1976;Aiello and Barra, 2010;Aiello et al., 2018). ...
... 2i-l. An infralittoral (Sgarrella and Moncharmont Zei, 1993), circalittoral and bathyal (Hayward et al., 2010) species, frequently assigned to the genus Cibicidella. The phylogenetic analyses of Schweizer et al. (2011) suggest that it should be attributed to Cibicidoides. ...
... 3-4; Ophthalmidium pusillum (Earland) - (Corliss, 1979), p. 5, pl. 1, figs. 7-8; Spirosigmoilina pusilla (Earland) - (Hayward et al., 2010), p. 157, pl. 9, figs. 19-20. ...
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The Late Quaternary benthic foraminiferal and ostracod assemblages from two continuous cores drilled in the Port of Salerno were studied to define their relationship with geochemical characteristics of the sediments and with the palaeoenvironmental evolution. The succession, ranging from Late Pleistocene to the 20th century, recorded the transition from a marine coastal environment under natural conditions to a depositional context affected by anthropogenic influence. In the lower part of the sequence, ecological and sedimentary changes were linked to sea-level changes due to Late Quaternary climatic phases, as well as to volcanic events such as the Campanian Ignimbrite eruption, represented by levels with high metal (Fe, Mn, Pb, Zn) concentrations, possibly leading to low pH phases. Later human activities, such as the construction of harbour facilities in the 18th century and the industrial development in the 19th century, influenced environmental variations, as shown in the upper part of the succession. High levels of heavy metal concentrations (Co, Cu, Fe, Pb, V) recorded in layers deposited in the 1800s suggest the presence of a pollution event which could be linked to manufacturing activities and might have occurred during the first part of the 19th century. Calcareous meiofaunal assemblages showed high diversity values, probably due to the occurrence of ”rare short lived” species in an unstable environment. Assemblages were dominated by the foraminiferal species Ammonia aberdoveyensis and Haynesina depressula, and by the ostracods Pontocythere turbida and Semicytherura sulcata, which are considered as possibly stress-tolerant species.
... Pouderoux et al. (2012aPouderoux et al. ( , 2014 undertook quantitative census counts of foraminiferal samples (> 125 μm) from several of the studied cores. Identified specimens were assigned to one of four associations based on the species' known living depths off New Zealand today (Hayward et al., 2010;Culver et al., 2012) and used to infer the mostly upper bathyal source areas of the turbidity currents (Pouderoux et al., 2012a). ...
... Several regression functions relating planktic percentage to water depth have been produced but none are suitable for use in this study because they are based on samples with test sizes > 125 μm and a maximum depth estimate of~1500 m (van der Zwaan et al., 1990;van Hinsbergen et al., 2005). Higher planktic percentages are sometimes obtained from samples with tests > 63 μm but the one available regression based on this size has a maximum water depth estimate of~1700 m and included stress-marker benthic species (Hayward et al., 2010). van Hinsbergen et al. (2005) make a strong case that stress-marker benthic species should be excluded from these regression calculations because they are not directly dependent on the long-term flux of organic carbon to the sea floor, which forms the basis for the depth relation of the planktic % regression. ...
... To interpret our test-size distribution data from the core samples we required similar data from a set of 10 modern seafloor samples (Table 2, Fig. 1) from a similar range of middle bathyal-upper abyssal depths (600-3000 m) also from off the east coast of New Zealand. These have previously been faunally documented as part of New Zealand-wide studies of the ecological distribution of deep-sea benthic foraminifera in the region (Hayward et al., 2010(Hayward et al., , 2013. Their planktic foraminiferal fragmentation index scores (Frag Index) had previously been determined using the method of Le and Shackleton (1992). ...
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... For assemblage analysis, sediments were sieved to >150 µm and split to fractions containing 300-600 foraminifera specimens for identification. Planktonic and benthic foraminiferal assemblages were identified to provide information on biostratigraphy, paleoceanography (Crundwell et al. 2008;Crundwell and Woodhouse 2022, Submitted), oceanicity (greater planktonic % corresponds to greater oceanicity; Hayward 1999;Hayward et al. 2001), and paleo-water depth (key benthic species; Crundwell et al. 1994;Hayward et al. 2010Hayward et al. , 2019 (Table S4). For stable δ 18 O and δ 13 C isotope analysis, where present, well-preserved planktonic (Neogloboquadrina incompta) and benthic foraminifera (Uvigerina peregrina) were picked from the >212 µm fraction and analysed using the Isoprime Dual-Inlet Isotope Ratio Mass Spectrometer at the University of Leeds, UK (Table S4). ...
... Increasing abundances of warm-water taxa at depths of <10 mbsf are consistent with regional deglaciation (Figure 2(A)). This is further supported by the presence of shallow water benthic foraminifera (shelfal to mid-bathyal, 0-1000 m; Hayward et al. 2010Hayward et al. , 2019 at Site U1520 (3520 mbsf) providing evidence for the allochthonous nature and downslope transport of the sediment at Site U1520. These data support the above suggestion that some radiocarbon dates provide upper depositional ages (Figure 7). Figure 4). ...
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... A total of 26 sites were sampled in triplicate (i.e., independent box corer deployments) along four ocean basins: Amazon, Par a-Maranhão, Barreirinhas, and Cear a. Ocean depth ranged from 525 to 2618 m, thus including mid bathyal (<1000 m), lower bathyal (1000-2000 m), and upper abyssal (2000-3000 m) depth zones (Table 1). Terminology for depth zones used in this study follows that in Hayward et al. (2010). ...
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... Since the intrusion of the 615 Kuroshio Branch Current and South China Sea Current feed the Taiwan Current that flows across 616 the Taiwan Strait (Fig.1b), the high %P values may be caused by the lateral advection of planktic 617 foraminifera produced further south where the water column is deeper and then deposited on the 618 shallow shelf typically characterized by low abundance of planktic foraminifera (Fig. 2b). In fact, 619 laterally transported planktic foraminifera by East Auckland Current has also been invoked to 620 explain high %P values in the shelf sediments off New Zealand Northland (Hayward et al., 2010). 621 2). ...
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The calcite tests of foraminifera are an important biogenic component of marine sediments. The abundance of foraminiferal tests in marine sediments broadly varies with bathymetry, thus has been used to reconstruct paleobathymetry. It is also promising as a tracer for downslope transport triggered by earthquakes and typhoons, especially if the displaced material from shallow locality contrasts strongly with the background autochthonous sediments in terms of foraminiferal abundance, such as the ratio of benthic and planktic foraminifera termed %P. However, its applicability in sediments off Taiwan has not been assessed. Taiwan is located in the path of typhoons and at tectonic plate margins, where typhoons and earthquakes may trigger submarine geohazards. This, combined with the fact that its seafloor spans a large bathymetric range, render this region an ideal natural laboratory to evaluate the applicability of %P as a proxy for tracing submarine geohazards and bathymetry. Here we report foraminiferal abundance, %P, grain size and elemental data from 148 surface sediment samples off 6 sectors off Taiwan, namely Southern Okinawa Trough, Hoping-Nanao-Hateruma Basins, Taitung-Hualien, Hengchun Ridge, Gaoping, and Changyun Sand Ridge. Of all the hydrographic and sedimentological parameters assessed, seafloor bathymetry is the major driver of foraminiferal abundance and %P in these regions. Notably, several data points deviate from the regional %P-water depth relationship. Based on sedimentological parameters and previous studies, we posit that these outliers may have to do with local sedimentation setting. These processes include earthquake-induced sediment transport via submarine canyon in the Southern Okinawa Trough, typhoon-triggered sediment flushing in Gaoping Canyon, cross-shelf and northward advection of planktic foraminifera on the Gaoping shelf, and carbonate dissolution in deep Hateruma Basin. Off Taiwan, the %P value in sediments increases exponentially with bathymetry (R2 = 0.72), and agrees well with the global calibration obtained by combining 827 data from several regions of the global ocean. The regional %P-water depth relationship may be useful for reconstructing paleobathymetry here, albeit with an uncertainty of ~400 m that increases with bathymetry especially >2000 m. Our results also highlight the potential of the %P index as a tracer for downslope transport and lateral advection in the water column. The downcore application of %P therefore has the potential to reconstruct past geohazard events while also identify autochthonous sediment sequences that are suitable for paleoceanographic reconstruction.
... Fourteen slides that were produced and examined during drilling of the well, but not used for the original report, were added into this present revision and faunal counts were made from them. A further 47 slides were briefly examined for the presence of key planktic species (Hayward 1986;Morkhoven et al. 1986;Hornibrook et al. 1989;Scott et al. 1990;Crundwell et al. 1994;Morgans et al. 1995;Cooper 2004;Hayward et al. 2010;Crundwell 2014), and some of these also had faunal counts made. ...
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This paper presents a reappraisal of datasets from Titihaoa-1, an offshore petroleum exploration drillhole that intersects a ∼2740 m-thick Holocene to early-middle Miocene sedimentary succession in the Titihaoa Sub-basin, part of the Hikurangi accretionary wedge. The well provides an important datapoint in the offshore southern Hikurangi subduction margin. We present new and revised foraminiferal biostratigraphic and paleoenvironmental interpretations that help to constrain age, depositional paleo-water depths, sedimentation rates, and oceanicity. Analysis of open-hole wireline and image-log datasets, combined with analogues from nearby outcrops, provide an improved understanding of the sedimentary architecture, depositional systems, and present-day in-situ stress at the drillhole site. The succession within Titihaoa-1 comprises a shallowing-upward succession of thin-bedded lower- to middle-bathyal turbidites, overlain by mudstone-dominated lithofacies deposited in the middle- to upper-bathyal and mid-shelf environments. The geological history and stratigraphic trends within the Titihaoa Sub-basin are analogous to other Neogene accretionary wedge basins within the Hikurangi Margin.
... The incoming of Nuttallides carinotrumpyi and the genera Karreriella and Vulvulina in the early EECO (late Waipawan and early Mangaorapan) indicate a deeper bathyal setting. The presence of Tritaxilina zealandica, from mid EECO to earliest post-EECO (middle Mangaorapan-early Heretaungan), suggests that this is the deepest interval in the section, probably lower bathyal (Hayward, 1986;Hayward et al., 2010). Foraminiferal assemblages higher in the post-EECO Heretaungan indicate shallowing with the disappearance of Karreriella and T. zealandica, although middle bathyal indicators persist into the Bortonian. ...
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The distribution of living (Rose Bengal-stained), dead and fossil benthic foraminifera was investigated in six short cores (multicores, 30–32 cm total length) recovered from the central Red Sea. The ecological preferences as well as the relationship between the live and dead/fossil assemblages (preserved down-core) were examined. The sites, located along a W-E profile and between the depth of 366 and 1782 m, extend from the center of the oxygen minimum zone (OMZ, ~200–650 m), through its margin at ~600 m, and down to the well-aerated deep-water environment. Live (Rose-Bengal stained) and coexisting dead foraminifera were studied in the upper 5 cm of each of the sites, and the fossil record was studied down to ~32 cm. Q-mode Principal Component Analysis was used and four distinct foraminiferal fossil assemblages were determined. These assemblages follow different water mass properties. In the center of the OMZ, where the organic carbon content is highest and the oxygen concentration is lowest (≤0.5 ml O2/1), the Bolivina persiensis-Bulimina marginata-Discorbinella rhodiensis assemblage dominates. The slightly more aerated and lower organic-carbon-content seafloor, at the margin of the OMZ, is characterized by the Neouvigerina porrecta-Gyroidinoides cf. G. soldanii assemblage. The transitional environment, between 900–1200 m, with its well-aerated and oligotrophic seafloor, is dominated by the Neouvigerina ampullacea-Cibicides mabahethi assemblage. The deeper water (>1500 m), characterized by the most oxygenated and oligotrophic seafloor conditions, is associated with the Astrononion sp. A-Hanzawaia sp. A assemblage. Throughout the Red Sea extremely high values of temperature and salinity are constant below ~200 m depth, but the flux of organic matter to the sea floor varies considerably with bathymetry and appears to be the main controlling factor governing the distribution pattern of the benthic foraminifera. Comparison between live and the dead/fossil assemblages reveals a large difference between the two. Processes that may control this difference include species-specific high turnover rates, and preferential predation and loss of fragile taxa (either by chemical or microbial processes). Significant variations in the degree of loss of the organic-cemented agglutinants were observed down core. This group is preserved down to 5–10 cm at the shallow OMZ sites and down to greater depths at well-aerated and oligotrophic sites. The lower rate of disintegration of these forms, in the deeper locations of the Red Sea, may be related to low microbial activity. This results in the preservation of increasing numbers of organic-cemented shells down-core.
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This manual is a concise, illustrated practical guide to the foraminiferal basis for the correlation and classification of New Zealand marine strata. The first part consists of seventeen short introductory chapters on the collection, preparation, curation and illustration of fossil foraminifera as well as containing sections on biology, nomenclature, classification, publishing journals, biostratigraphic practice and stages. A chapter on time scales and overseas correlations deals briefly with radiometric dating methods and the application of magnetic polarity stratigraphy to geochronology. A chapter on depth paleoecology deals with well known examples of Cretaceous and Cenozoic biofacies. The second part deals with the key fusulinid foraminifera of the Permian and key species of the Triassic and the New Zealand Cretaceous and Cenozoic stages. The history, definition, key foraminifera, stratotypes and distribution of the Cenozoic stages are dealt with in most detail. Over 500 species of benthic and planktonic foraminifera are illustrated and their updated time ranges are given. -from Authors
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Several very large, taxonomically standardized data sets have been compiled and utilized to investigate biogeographic and evolutionary patterns of continental margin benthic foraminifera. Mean partial species durations for 87 frequently occurring and 180 rarely occurring species on the Atlantic continental margin of North America are the same, namely 21 m.y. The global fossil record of these species indicates no center or centers of origin and indicates very rapid dispersal. The Miocene had the greatest number of first occurrences with 46%, followed by the Pleistocene, Pliocene and Oligocene with approximately 13% each. The remaining 14% first occur in the Eocene, Paleocene, and Cretaceous. Species with a wide geographic distribution often exhibit longer species durations than those with narrow geographic ranges. The vast majority of endemic species (150 of 175) occur rarely and have no fossil record. 1989 The Paleontological Society.