Planktonic Foraminifers Research Articles

Influences of Atlantic Ocean thermohaline circulation and Antarctic ice-sheet expansion on Pliocene deep Pacific carbonate chemistry

Quantifying changes in seawater carbonate chemistry is crucial to deciphering of patterns and drivers of the oceanic carbon cycle and climate change. Here, we present a new deep-water carbonate ion saturation state (Δ[CO32−]) record for the Pliocene western tropical Pacific, reconstructed from the size-normalized weight of the planktonic foraminifer Trilobatus sacculifer of IODP Site U1490. A steep decline in deep-water Δ[CO32−] occurred at ∼4.6 Ma synchronous to the enhanced production of North Atlantic Deep Water (NADW) related to the closure of the Panamanian Gateway. Subsequently, at the onset of the Northern Hemisphere glaciation at ∼2.7 Ma the weakening of NADW formation resulted in a deep-water Δ[CO32−] peak. The changes in NADW production rate likely controlled a seesaw-like fluctuation in deep-water Δ[CO32−] between the Pacific and Atlantic oceans. During the late Pliocene (∼3.8–2.8 Ma), Antarctic ice-sheet/sea-ice expansions sequestered CO2 in the deep Pacific through ventilation of the deep watermass, leading to a long-term decrease in deep Pacific Δ[CO32−]. We infer that fluctuating NADW production rates at ∼4.6 Ma and ∼2.7 Ma influenced inter-basinal fractionation of deep-ocean carbon between the Atlantic and Pacific, and that deep Pacific carbon storage linked to expansions of Antarctic ice sheet/sea ice contributed to the lowering of atmospheric pCO2 and global cooling during the late Pliocene.

Maastrichtian extinctions of planktonic foraminifera in Central and Eastern Poland

Three main steps in the extinction of planktonic foraminifers can be distinguished in the axial zone of the Danish-Polish Trough during the latest Maastrichtian of the Central Poland (Foraminiferal Transitional Province): 1. The extinction in the late Belemnitella junior Zone of all species of Globotruncana . 2. The extinction in the late Hoploscaphites constrictus crassus Zone of all species of Rugoglobigerina which is shortly followed by 3; 3. The extinction of the last planktonic species of the genera Heterohelix , Globigerinelloides and Guembelitria. The late Maastrichtian worldwide regression, which coincided with tectonic activity in the Danish-Polish Trough and the cooling of the climate following the regression were most probably responsible for the extinctions of planktonic foraminifers in the area studied during latest Maastrichtian.

Maastricthtian ammonite and inoceramid ranges from Bay of Biscay Cretaceous-Tertiary boundary sections

New collecting of ammonites and inoceramid bivalves from Cretaceous-Tertiary boundary sections exposed al Sopelana and Zumaya, Spain, and Hendaye and Bidart (Biarritz), France, has led to better understanding of molluscan biostratigraphy in each of these coastal exposures. Ali of these sections can be lithologically correlated. At all of the sections, ammonites have now been found within the last meter of the Cretaceous. Also, in all of the sections, inoceramid bivalves disappear near the base A . mayaronensis planktonic foram zone, the only exception being the small, enigmatic bivalve genus Tenuipteria , which ranges up to the Cretaceous-Tertiary boundary.

Upper Miocene deposits at the southern margin of the Guadalquivir Foreland Basin (central Betic Cordillera, S. Spain). Implications for the closure timing of the Atlantic-Mediterranean connections

Mixed siliciclastic-carbonate deposits accumulated in several satellite sub-basins at the southern margin of the Guadalquivir Basin, the foreland basin of the Betic Cordillera (S. Spain). The prevailing coarse-grained sediments and deposition in shallow-water settings make it difficult to establish the precise age of the complete successions. For this reason, in previous studies, these deposits were attributed to the late Tortonian, although a Messinian age was not totally ruled out. The age of the upper Miocene deposits in the central part of the Guadalquivir Basin is here re-evaluated based on the analysis of several sections distributed in different areas: Antequera, Iznájar-Cuevas de San Marcos, Teba, and Bobadilla Estación. According to planktonic foraminifer and nannoplankton assemblages, the marine sedimentary infill of this sector of the southern margin of the Guadalquivir Basin is late Tortonian-early Messinian (late Miocene) in age. The occurrence of marine deposits characterized by the dominance of Globorotalia miotumida group, dextrally-coiled G. scitula, and the presence of G. margaritae, Globigerina multiloba, Discoaster quinqueramus, Amaurolithus primus, A. amplificus, and Reticulofenestra rotaria at the northern end of the Guadalhorce Corridor, the last active gateway in the Betic Cordillera connecting the Atlantic and the Mediterranean, indicates that it remained open until the early Messinian.

Calcification of planktonic foraminifer Neogloboquadrina pachyderma (sinistral) controlled by seawater temperature rather than ocean acidification in the Antarctic Zone of modern Sothern Ocean

Calcification of planktonic foraminifer Neogloboquadrina pachyderma (sinistral) controlled by seawater temperature rather than ocean acidification in the Antarctic Zone of modern Sothern Ocean

Developmental plasticity in deep time: a window to population ecological inference

AbstractDevelopmental plasticity, where traits change state in response to environmental cues, is well studied in modern populations. It is also suspected to play a role in macroevolutionary dynamics, but due to a lack of long-term records, the frequency of plasticity-led evolution in deep time remains unknown. Populations are dynamic entities, yet their representation in the fossil record is a static snapshot of often isolated individuals. Here, we apply for the first time contemporary integral projection models (IPMs) to fossil data to link individual development with expected population variation. IPMs describe the effects of individual growth in discrete steps on long-term population dynamics. We parameterize the models using modern and fossil data of the planktonic foraminiferTrilobatus sacculifer. Foraminifera grow by adding chambers in discrete stages and die at reproduction, making them excellent case studies for IPMs. Our results predict that somatic growth rates have almost twice as much influence on population dynamics than survival and more than eight times more influence than reproduction, suggesting that selection would primarily target somatic growth as the major determinant of fitness. As numerous paleobiological systems record growth rate increments in single genetic individuals and imaging technologies are increasingly available, our results open up the possibility of evidence-based inference of developmental plasticity spanning macroevolutionary dynamics. Given the centrality of ecology in paleobiological thinking, our model is one approach to help bridge eco-evolutionary scales while directing attention toward the most relevant life-history traits to measure.

K-Pg boundary transition and attendant degeneration of clay lattices in late Maastrichtian-early Danian shelf facies of the Langpar formation, Meghalaya, India

Environmental effects of the Deccan volcanism and potential causes for the Cretaceous-Palaeogene (K-Pg) boundary mass extinction have not been resolved completely. Earlier studies on shallow-marine facies of the Um-Sohryngkew River (USR) K-Pg boundary section revealed notable cell parametric variations and changes in the inter-atomic distances in illite and kaolinite lattices associated with the yellowish brown clayey (JP-12) and shaly marlite (JP-14) layers of the CF3 and P0 biozones which correspond to negative Ce anomalies and sudden break in the planktonic foraminifers abundance, respectively. Similar studies are lacking on a contiguous, well-preserved shelf-facies of the Mahadeo-Cherrapunji road (MCR) section. In this contribution we address environmental shift across K-Pg boundary using clay minerals. Obtained results are compared to the clay attributes of the USR succession. X-ray diffraction patterns revealed Illite > Illite/Smectite > kaolinite > Chlorite > Montmorilloite assemblages throughout the MCR succession. This in combination and widespread variation in the clay mineral assemblages suggest highly variable source terrains and lack of sediment mixing during transport. Illite/Smectite mixed-layer clays occur with both kaolinite and chlorite, reveal a seasonal weather (warm-wet, warm-dry) variation in the source area. A major deviation in the cell parameters, and inter-atomic distances, and distortion in the physil lattices associated with the gray calcareous shale layer that lie between biozones CF1-P0 of both the USR and MCR sections is attributed to K-Pg boundary transition events including frequent local sea-level changes, Abor volcanic extrusions, Indian and Eurasian plates collision, and green-house effects of the Deccan volcanism.

Planktonic Foraminiferal Biostratigraphy of Shiranish Formation in Sara Anticline in Dokan Area, Northeastern Iraq

Planktonic Foraminiferal Biostratigraphy of Shiranish Formation in Sara Anticline in Dokan Area, Northeastern Iraq

Planktonic foraminifera and stable isotopes of the upper Cenomanian–middle Turonian in central Tunisia: Implications for bioevents synchronicity and paleoenvironmental turnover

The upper Cenomanian–middle Turonian planktonic foraminifers and stable isotopes analyses of the Oued Ettalla section (central Tunisia) were incorporated to establish the temporal framework and unveil the paleoenvironmental signal of the Oceanic Anoxic Event 2 (OAE2). Some bioevents were reported at a lower stratigraphic level compared to their worldwide records; such as the synchronous extinction of Rotalipora cushmani and Globigerinelloides bentonensis at the onset of the δ13C peak A, besides the Heterohelix shift between δ13C peaks A and B. Thus, an intensified surface-water eutrophism complemented by a local acceleration in the thermal stratification collapse of the upper water column had occurred by the OAE2 onset. The results assign the pre-OAE2 interval to stable, reasonably ventilated meso-oligotrophic surface-water conditions. The paleoenvironment had shifted toward stressed, highly eutrophic, less stratified circumstances by the OAE2 onset, as evidenced by eliminating the taxa that occupied deep and intermediate habitats. The planktonic foraminifers alongside oxygen isotopes data denote an extreme warm condition during the OAE2 with a brief cooling episode, slightly after the δ13C peak A, equivalent to the so-called Plenus Cold Event. The presence of whiteinellids and prevalence of dwarfism excluded each other among the planktonic foraminifers assemblage within the OAE2 interval, indicating minor shifts in the eutrophication. The environmental wakeup from the OAE2 was stepwise and initiated well within the topmost part of the Whiteinella archaeocretacea Zone, as reflected from the permanent existence of the whiteinellids and the associated reoccurrence of the keeled taxa.

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The Aaliji Formation in wells (BH.52, BH.90, BH.138, and BH.188) in Bai Hassan Oil Field in Low Folded Zone northern Iraq has been studied to recognize the palaeoenvironment and sequence stratigraphic development. The formation is bounded unconformably with the underlain Shiranish Formation and the overlain Jaddala Formation. The microfacies analysis and the nature of accumulation of both planktonic and benthonic foraminifera indicate the two microfacies associations; where the first one represents deep shelf environment, which is responsible for the deposition of the Planktonic Foraminiferal Lime Wackestone Microfacies and Planktonic Foraminiferal Lime Packstone Microfacies, while the second association represents the deep-sea environment that is responsible for deposition of Lime Mudstone Microfacies. The sequence boundaries were marked on SB1 surface on the bottom and the top of the succession while SB2 surface is placed at the top of the sequence (1) as shallowing-upward beneath deepening upward units. Sequence (1) placed on SB1 surface that separates the Cretaceous from the Palaeogene successions where it formed outer shelf to upper-middle bathyal, and comprised the Planktonic Foraminiferal Lime Wackestone Microfacies as a Transgression System Tract TST deepening-upward ended with Maximum Flooding Surface MFS represented by Mudstone microfacies in BH.188 Well. It is followed by the Planktonic Foraminiferal Lime Packstone Microfacies that represent the Highstand System Tract HST as a shallowing-upward ended by SB2. Sequence (2) begins with a new Transgression System Tract TST that formed the outer shelf and bounded with Maximum Flooding Surface MFS. The Highstand System Tract HST that shallowing-upward which ended by SB1 between the Aaliji and Jaddala Formations.

Globorotalia truncatulinoides in the Mediterranean Basin during the Middle–Late Holocene: Bio-Chronological and Oceanographic Indicator

The planktonic foraminiferal species Globorotalia truncatulinoides is widely used as a biostratigraphic proxy for the Quaternary in the Mediterranean region. High-resolution quantitative studies performed on sediment cores collected in the central and western Mediterranean Sea evidence a significant abundance of G. truncatulinoides during the Middle Holocene. The robust chronological frame allows us to date this bio-event to 4.8–4.4 ka Before Present (BP), very close to the base of the Meghalayan stage (4.2 ka BP). As a consequence, we propose that G. truncatulinoides can be considered a potential marker for the Middle–Late Holocene chronological subdivision. G. truncatulinoides is a deep-dwelling planktonic foraminifer and their distributional pattern in the central and western Mediterranean Sea provides a tool to monitor the onset of the regional deep vertical mixing of the water column. During the Holocene, the significant increase in the abundance of this species is in phase with the end of African Humid Period, which marks the transition from a more humid climate to the present-day semi-arid climate.

Trophic niche separation of two non-spinose planktonic foraminifers Neogloboquadrina dutertrei and Pulleniatina obliquiloculata

Based on laboratory observations, planktonic foraminifers are omnivorous, feeding zooplankton and phytoplankton. Spinose species tend toward greater dependence on zooplankton prey than on phytoplankton prey, while non-spinose species are more adapted to herbivorous diets. However, the trophic activity of planktonic foraminifers in the natural environment and their trophic positions in the marine food web have not yet been fully understood. The trophic position (TP) of two non-spinose species, Neogloboquadrina dutertrei and Pulleniatina obliquiloculata, was determined by differences in the nitrogen isotopic composition between two amino acids (glutamic acid and phenylalanine). Results show that TP values of N. dutertrei were ~ 2.4, indicating dependence on omnivorous (mixed herbivorous and carnivorous) diets, while those of P. obliquiloculata were ~ 2.1, indicating dependence on herbivorous diets. Together with previous laboratory observations, these TP values suggest that N. dutertrei is a detritivore or scavenger, while P. obliquiloculata is generally a herbivore. This trophic niche separation likely allows these two planktonic foraminiferal species to live within a similar depth zone in the open water column and provides a clue for understanding causes of spatial and temporal changes in their relative abundances in living and sediment assemblages.

Organic petrography and depositional environments of the upper Eocene Kopili Shale, Bengal Basin, Bangladesh

Mudrock samples of the upper Eocene Kopili Shale, taken from the outcrops in the northeastern Sylhet Trough areas, and drilled cores from the Indian Platform in the northwestern Bangladesh, were investigated in order to present an overview of the depositional environment. Several techniques such as organic petrography, thin section petrography, X-Ray fluorescence (XRF) elemental analysis, X-Ray diffraction (XRD) mineralogical analysis, and lithologic observations were combined to draw the best possible conclusions.Organic petrographic analysis shows higher proportion of vitrinite along with liptinitic materials in the northeastern samples, suggesting deposition in an upper deltaic environment, whereas the northwestern samples show abundance of inertinite, indicating deposition in a lower deltaic environment. Thin section petrographic analyses, which reveal planktonic foraminifers, bioturbated fabrics, pyrite framboids, sand lenses and flame structures; and XRD and XRF analyses reveal abundance of quartz and illite in Kopili Shale, all of which suggest deposition in shallow marine reducing environments.The fauna in the Kopili Shale can be correlated to upper Eocene faunas of the Tethys Sea around the Indian subcontinent. Organic petrographic analysis suggest provenance from a low-relief crystalline Indian craton located adjacent to the west, rather than the Himalayan or Indo-Burman ranges to the north and east of the Bengal basin. Taken together, the present results suggest that the Kopili Shale of the Bengal basin is a silty mudrock, which was deposited during rapid marine transgression and regression, in a deltaic near-shore setting.

Calcium Carbonate Dissolution Triggered by High Productivity During the Last Glacial–Interglacial Interval in the Deep Western South Atlantic

Studies reconstructing surface paleoproductivity and benthic environmental conditions allow us to measure the effectiveness of the biological pump, an important mechanism in the global climate system. In order to assess surface productivity changes and their effect on the seafloor, we studied the sediment core SAT-048A, spanning 43–5 ka, recovered from the continental slope (1,542 m water depth) of the southernmost Brazilian continental margin, deep western South Atlantic. We assessed the sea surface productivity, the organic matter flux to the seafloor, and calcite dissolution effects, based on micropaleontological (benthic and planktonic foraminifers, ostracods), geochemical (benthic δ13C isotopes), and sedimentological data (carbonate and bulk sand content). Superimposed on the induced changes related to the last glacial–interglacial transition, the reconstruction indicates a significant and positive correlation between the paleoproductivity proxies and the summer insolation. From the reconstructed data, it was possible to identify high (low) surface productivity, high (low) organic matter flux to the seafloor, and high (low) dissolution rates of planktonic Foraminifera tests during the glacial (postglacial). Furthermore, within the glacial, enhanced productivity was associated with higher insolation values, explained by increased northeasterly summer winds that promoted meandering and upwelling of the nutrient-rich South Atlantic Central Water. Statistical analyses support the idea that productivity is the main cause for seafloor calcium carbonate dissolution, as opposed to changes in the Atlantic Meridional Overturning Circulation (at least for the 25–4 ka period). Further efforts must be invested in the comprehension and quantification of the total organic matter and biogenic carbonate burial during time intervals with an enhanced biological pump, aiming to better understand their individual roles.

Paleozoic-Mesozoic turnover of marine biological pump and Mesozoic plankton revolution

<p indent="0mm">The evolution of deep-time marine biological pumps (BPs) is critical to our understanding of the processes and mechanisms of the present-day carbon cycle. The Late Paleozoic-Early Mesozoic was a key period for the formation of modern marine biological pumps. Two types of Phanerozoic biological pump have been recognized: Paleozoic (Paleozoic-Middle Triassic) and Modern (Late Triassic-Modern). The Paleozoic-type pump comprises benthic algae and acritarch, whereas the Modern-type pump consists mainly of pelagic plankton. Geological records show that the Permian-Triassic extinction event destroyed the Paleozoic BP. Then, a special BP composed of cyanobacteria and other autotrophic bacteria, briefly appeared during the Permian-Triassic extinction interval. The Modern-type BP consists primarily of pelagic nannoplankton that originated in the Late Triassic. Fossil records suggest that the origin and rapid radiation of nannoplankton (coccoliths and dinoflagellates) during the Late Triassic to Early Jurassic promoted the establishment of modern plankton ecosystem. The rise of pelagic plankton such as dinoflagellates, coccolithophores, and planktonic foraminifers in the Mesozoic is summed up as the Mesozoic plankton revolution. The Mesozoic plankton revolution changed the patterns of marine material cycling and energy flow. The proliferation of nannoplankton accelerated the transfer of material and energy from primary producers to larger consumers and higher trophic levels, increasing the resources available to mesotrophic levels of marine ecosystems. The increased availability of energy resulted in rapid changes in composition, spatial structure, and food chain structures of marine fauna. The resulting “biological arms race” is summarized as the Mesozoic marine animal revolution. The Mesozoic plankton revolution was also the key driver of the Mid-Mesozoic revolution in terms of the regulation of ocean chemistry. Before the Early Jurassic, fluctuations in sea level, ocean area, continental weathering rates, and oceanic calcium ion concentrations produced large perturbations in carbonate deposition and the oceanic carbon cycle, which were only weakly buffered by the ocean. After the Early Jurassic, seawater chemistry changed—With the decrease and stabilization of carbonate saturation due to the transfer of biogenic carbonate from the shallow to the deep marine deposits—Mainly as a result of the rise of nannoplankton and tectonic movement. Changes in seawater chemistry are also reflected in the increased oxygen concentration therein. The oxygen concentration was higher on the Jurassic shelf, likely due to pelagic planktonic algal blooms. The occurrence of phytoplankton increased the efficiency of pelagic biological and carbonate pumps, and the accumulation and dissolution of deep-sea carbonates began to emerge as an important link in the carbon cycle; this improved the buffering capacity of ocean against environmental disturbances. It also provided a stable environment for the creation of modern marine ecosystem, and several oceanic anoxic events that occurred in the Mesozoic did not directly lead to mass extinctions of marine animals, causing only small fluctuations in the diversity of some taxa. Therefore, the Mesozoic plankton revolution is a critical link between the animal and chemical revolutions, and these three processes make up the Mesozoic marine revolution. The origin and evolution of key marine producers and their controlling factors are important topics that need to be studied. However, there are few high-precision studies on the evolution of primary producers and biological pumps during the Late Paleozoic-Early Mesozoic. In addition, the timeline and mechanisms driving the origin of pelagic phytoplankton are key questions that need to be addressed. To solve these problems, the evolution of photosynthetic pigment lineages and the paleogeographic distribution of algae, along with the changes in the size of plankton during the early Mesozoic, require further research attention.

Why is intercontinental correlation within the Lower Cambrian so difficult?

Correlation of Lower Cambrian rocks is hampered because there are no widespread and rapidly evolving organisms such as the later agnostids, graptolites, conodonts, ammonites, or planktonic foramini fers, that might provide the basis for a consistent intercontinental biostratigraphy. Four problems illustrate the issue: 1) the age of the oldest trilobites of China; 2) acritarch correlations between Siberia and Baltica; 3) conflicts between archaeocyath and trilobite correlations; and 4) the location of the Lower Cambrian/Middle Cambrian boundary. There is no basis for an internationally useful set of Lower Cambrian stages at this time.

Radiolaria and planktonic foraminifera from Sarama composite section of the Kannaviou Formation (Campanian, Upper Cretaceous, Cyprus)

Radiolarians and planktonic foraminifers were studied from a series of continuous outcrops of the Upper Cretaceous (upper Campanian) Kannaviou Formation near Sarama Village (southwestern Cyprus). The composite study section has a narrow stratigraphic interval that covers the upper Campanian, with a total thickness of more than 70 m. The Amphipyndax tylotus (radiolarian) Zone is found within the study section. According to foraminiferal data the studied interval corresponds to the middle-upper Campanian age (from Contusotruncana plummerae Zone to the lower part of Gansserina gansseri Zone).

PROBLEMS IN USING ICHNOFACIES FOR DEPOSITIONAL ENVIRONMENT INTERPRETATION CASE STUDY: THE CISAAR FORMATION, SUNGAI CISAAR, SUMEDANG DISTRICT, WEST JAVA, INDONESIA

Although numerous researchers have used trace fossils method to determine depositional environment, this method is still considered less robust. This is due to the finding of several similar trace fossils in two or more diverse environments, leading to irrelevancy in environmental interpretation. Therefore, we conducted this study in order to verify how powerful the trace fossil analysis is, by applying this method to interpret the depositional environment of the Cisaar Formation in the Cihanyir Tonggoh area, Sumedang Regency, West Java. We combined trace fossil study with foraminiferal assemblage analysis and vertical succession of related sedimentary units. For this study, 19 rock samples that have been collected from outcrop along 16 m traverse and 14 m measured stratigraphic sections were examined.The result of the study shows that shallow marine trace fossils which were developed at the edge of the shelf, were transported into the basin by gravitational mass flow and re-deposited as deep marine turbidites. Trace fossils were generally found in sandstones, while planktonic foraminifers were found in claystones-sandstones interbeds. This study concludes that to avoid inconsistency in the interpretation of the depositional environment, performing trace fossils method must be integrated with other methods, e.g. analysis of lithofacies and biofacies.

Planktonic Foraminiferal Biostratigraphy of the Upper Cretaceous of the Central European Basin

Planktonic foraminifera are one of the most stratigraphically important groups of organisms for the Cretaceous system. However, standard foraminiferal zonations based mostly on species from the Tethyan bioprovince are hardly applicable in temperate regions where warm-water taxa are scarce or lacking. We propose a foraminiferal zonation based on foraminiferal events recognized in the northern Foraminiferal Transitional Bioprovince, which likely has a high correlation potential at least at a regional scale. Fifteen planktonic foraminiferal zones are distinguished from the upper Albian up to the uppermost Maastrichtian strata in extra-Carpathian Poland and western Ukraine. From the bottom to the top, Thalmanninella appenninica, Th. globotruncanoides, Th. reicheli, Rotalipora cushmani, Whiteinella archaeocretacea, Helvetoglobotruncana helvetica, Marginotruncana coronata, M. sinuosa, Pseudotextularia nuttalli, Globotruncana linneiana, G. arca, Contusotruncana plummerae, Rugoglobigerina pennyi, Globotruncanella petaloidea and Guembelitria cretacea. These zones are calibrated by macrofaunal zonations.

Characterization of calcite spines of planktonic foraminifers (Globigerinidae)

Spines projecting from a trochospiral test of a spinose planktonic foraminifer are a single-crystal-like calcite that has a nanogranular texture containing microstrain and an organic envelope.