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Benthic foraminifera, carbonate microfacies identification, and geochemical analysis of the Permian intervals of Pleshet-1 and David-1 boreholes from western Israel,-allowed a determination of their time frame and tectono-sedimentary relationships, further allowing insights about the nature and regional subsurface expression of the Permian. Carbonate horizons within the mixed lithology successions, yielded foraminifera suggesting the Middle/Late Permian transition. The carbonate microfacies and related stable isotopic profiles indicate a change from siliciclastic marginal marine conditions (Saad Fm.) to fully marine platform conditions (Arqov Fm.) in a gradual marine transgression onto a segmented peneplain, and producing sedimentary facies belts striking SW–NE. A comparison of this work with previous work in southern and eastern Israel suggests that the Permian formations in Israel formed NW to SE diachronistically, by marine transgression during the Middle and the Late Permian, with maximum flooding during the Changhsingian. It appears that although not precisely defined, the regional Middle/Late Permian transition happened during a major marine transgression, characterized by a negative to positive stable isotope shift, and by apparently gradual aridization of the hinterland. The regional onset of sedimentation occurred on a marginally superficially downfaulted northwestward peneplain, subdivided tentatively into four segments with shallow half-graben structures. The three eastern segments ceased their differential movements and maintained uniform northwestward subsidence during the late Wuchiapingian–Changhsingian. The most western fourth segment had differential fault activity through the Triassic and the Jurassic, and is proposed to be placed on a transition to a proximal tectonic necking zone. [ABSTRACT FROM AUTHOR]

Abstract One hundred and forty‐four published successions of shallow‐water carbonates, deposited between the Palaeocene and the Miocene, from the Levant to the Himalayas, have been re‐analysed using a standardised approach to investigate the distribution of carbonate facies and carbonate‐producing organisms. Large benthic foraminifera were found to be the volumetrically most important group of carbonate producers during the whole period, with a peak in abundance during the Eocene. Colonial corals are relatively abundant during the Palaeocene and Miocene, their abundance peaks during the Oligocene and has a minimum during the Eocene. Red calcareous algae have a similar pattern although their peak in abundance covers both the Oligocene and Miocene. Green calcareous algae decrease from the Palaeocene onward. Facies related to very shallow and/or restricted marine conditions peak during the Miocene and in particular during the Aquitanian. Both the pattern of large benthic foraminifera and of colonial corals seems to be related to temperature, with warm periods favouring the former group and cool periods the latter group. Red calcareous algae display a pattern similar to that of colonial corals suggesting that the periods favourable for one group are, on a large scale, also favourable for the other. The progressive decrease of green calcareous alga could be tentatively related to a preservation bias connected to the transition from Palaeogene assemblages that included presumably calcitic taxa of green algae to Neogene assemblages entirely constituted by aragonitic taxa with limited preservation potential. The Aquitanian peak in facies related to very shallow and/or restricted marine conditions is most likely connected to the progressive narrowing of the Tethys related to the collision between Arabia and Eurasia. These results denote an overall agreement between the abundance of the various types of shallow‐water carbonate facies and large‐scale environmental and geological processes, highlighting the potential for palaeoenvironmental reconstruction locked in the shallow‐water record.

The Eocene Large Benthic Foraminiferal limestones of the Tethyan margins are proven hydrocarbon reservoirs. This study examines the controls on porosity and permeability development of the producing Middle Eocene Pirkoh Member of the Eastern Tethys using well core data from Well Zx-01 from the Punjab Platform area, Central Indus Basin, Pakistan. The standard petrographic and core analysis techniques were adopted to determine these controls. Petrographic studies revealed three microfacies comprising bioclastic packstone to floatstone, bioclastic wackestone and mud-wackestone microfacies. The allochems belong to benthic foraminifera including Nummulites sp., Discocyclinids sp.., Coralline algae, Assilina sp., Lockhartia sp., Coralline algae and Gastropods along with the other bioclastic debris. These allochems were found embedded in the micritic matrix with extensive cementation of calcite. The diagenetic events included cementation, compaction, dolomitization, fracture filling and neomorphism. Based on microfacies, the environment of deposition is interpreted to be a high-energy zone of the middle ramp in shallow marine environment. Subsurface core indicates that the porosity of the reservoir is low to high ranging between 6 to 27.47% and permeability is found low to fair ranging between 0.03 to 7.73 mD, found closely related to microfacies and diagenetic modifications. This study is a first attempt to document the reservoir facies of the non-reefal carbonates of the Pirkoh limestone that would help to exploit the reservoir's potential of the carbonate platforms developed in similar settings worldwide. [ABSTRACT FROM AUTHOR]

The lithium (Li) isotopic composition of carbonates is considered to be a reliable archive of past seawater Li isotopic compositions, which are useful as a tracer of silicate weathering. However, δ7Li values have been shown to be dependent on either pH or DIC in two studies using similar species of large, benthic foraminifera from the genus Amphistegina. To resolve this issue, we conducted culture experiments on Amphistegina lessonii in decoupled pH–DIC conditions, under two different light treatments, and with normal or Li-enriched seawater. The δ7Li values and Li/Ca ratios in the foraminifera tests were analysed by ion microprobe and LA-ICP-MS, respectively. No links between either the pH or DIC and δ7Li or Li/Ca values were observed for any of the treatments, and growth rates also did not seem to influence the Li incorporation or isotopic fractionation, contrary to observations from inorganic carbonate-precipitation experiments. Overall, these findings appear to support the use of Li isotopes in large benthic foraminifera to reconstruct past seawater chemistry and to infer changes in chemical weathering during carbon-cycle perturbations. [ABSTRACT FROM AUTHOR]

Large benthic foraminifera are an integral component of shallow-water tropical habitats and like many marine calcifiers, are susceptible to ocean acidification (OA) and ocean warming (OW). In particular, the prolific Symbiodiniaceae-bearing and high-magnesium calcite Marginopora vertebralis has a low threshold compared to several diatom-bearing and low-magnesium calcite species. In this multi-year mesocosm experiment, we tested three RPC 8.5 climate change scenarios (i) present day, (ii) the year 2050, and (iii) 2100. To enable a realistic epiphytic association, these experiments were uniquely conducted using natural carbonate substrate, living calcifying alga, and seagrass. In contrast to previous studies, we detected no reduction in surface-area growth under future climate conditions compared with present day conditions. In terms of calcification, M. vertebralis' epiphytic association to primary producers (i.e., calcifying algae and seagrasses) potentially ameliorates the effects of OA by buffering against declines in boundary layer pH during periods of photosynthesis (i.e., CO2 removal). Importantly for population maintenance, we observed a strong reduction in asexual fecundity under the 2100 scenario. We propose the additional energy needed to maintain growth might be one reason for drastically reduced asexual reproduction. An alternative explanation could be that the 2 °C temperature increase interfered with the environmental synchronization that triggered asexual multiple fission. We conclude that the low levels of reproduction will reduce populations in a high CO2 environment and reduce a valuable source of CaCO3 sediment production. [ABSTRACT FROM AUTHOR]

Foraminifera are highly diverse and have a long evolutionary history. As key bioindicators, their phylogenetic schemes are of great importance for paleogeographic applications, but may be hard to recognize correctly. The phylogenetic relationships within the prominent genus Amphistegina are still uncertain. Molecular studies on Amphistegina have so far only focused on genetic diversity within single species and suggested a cryptic diversity that demands for further investigations. Besides molecular sequencing-based approaches, different mass spectrometry-based proteomics approaches are increasingly used to give insights into the relationship between samples and organisms, especially as these do not require reference databases. To better understand the relationship of amphisteginids and test different proteomics-based approaches we applied de novo peptide sequencing and similarity clustering to several populations of Amphistegina lobifera, A. lessonii and A. gibbosa. We also analyzed the dominant photosymbiont community to study their influence on holobiont proteomes. Our analyses indicate that especially de novo peptide sequencing allows to reconstruct the relationship among foraminiferal holobionts, although the detected separation of A. gibbosa from A. lessonii and A. lobifera may be partly influenced by their different photosymbiont types. The resulting dendrograms reflect the separation in two lineages previously suggested and provide a basis for future studies. [ABSTRACT FROM AUTHOR]

Symbiont-bearing perforated large benthic foraminifers are vital to the formation of coral reef islands in the Pacific Ocean and are affected by the deterioration of reefal water quality in urbanized atolls. Recently, road traffic was identified as a notable source of heavy-metal pollution in the densely populated area of Majuro atoll in the Marshall Islands. However, the effects of polycyclic aromatic hydrocarbons (PAHs) on LBFs have not been investigated so far. In the present study, pyrene, a PAH, was selected, and its effects on photosynthesis were examined by using Calcarina gaudichaudii. The organisms were exposed to 0.02, 2.0, and 200 µg L−1 of pyrene for 8 d. The effective and maximum quantum yields did not change (p > 0.05). Chlorophyll-a content too remained constant (p > 0.05). The results indicate that pyrene does not damage the photosystem II and symbiotic algal cell in C. gaudichaudii. Although a previous study reported that the cell density of a marine diatom decreased on exposure to 125 µg L−1 of pyrene, the Langmuir adsorption isotherm model confirmed that pyrene was sufficiently adsorbed on the dried shell of C. gaudichaudii. Through visual observation, sticky materials such as the extracellular organic matrix around C. gaudichaudii were identified under exposure to pyrene. This extracellular organic matrix likely acted as a protective layer against the toxic effects of pyrene with different defense mechanisms found in coral. We conclude that C. gaudichaudii can tolerate short-term exposure to pyrene. [ABSTRACT FROM AUTHOR]

One hundred and forty‐four published successions of shallow‐water carbonates, deposited between the Palaeocene and the Miocene, from the Levant to the Himalayas, have been re‐analysed using a standardised approach to investigate the distribution of carbonate facies and carbonate‐producing organisms. Large benthic foraminifera were found to be the volumetrically most important group of carbonate producers during the whole period, with a peak in abundance during the Eocene. Colonial corals are relatively abundant during the Palaeocene and Miocene, their abundance peaks during the Oligocene and has a minimum during the Eocene. Red calcareous algae have a similar pattern although their peak in abundance covers both the Oligocene and Miocene. Green calcareous algae decrease from the Palaeocene onward. Facies related to very shallow and/or restricted marine conditions peak during the Miocene and in particular during the Aquitanian. Both the pattern of large benthic foraminifera and of colonial corals seems to be related to temperature, with warm periods favouring the former group and cool periods the latter group. Red calcareous algae display a pattern similar to that of colonial corals suggesting that the periods favourable for one group are, on a large scale, also favourable for the other. The progressive decrease of green calcareous alga could be tentatively related to a preservation bias connected to the transition from Palaeogene assemblages that included presumably calcitic taxa of green algae to Neogene assemblages entirely constituted by aragonitic taxa with limited preservation potential. The Aquitanian peak in facies related to very shallow and/or restricted marine conditions is most likely connected to the progressive narrowing of the Tethys related to the collision between Arabia and Eurasia. These results denote an overall agreement between the abundance of the various types of shallow‐water carbonate facies and large‐scale environmental and geological processes, highlighting the potential for palaeoenvironmental reconstruction locked in the shallow‐water record. [ABSTRACT FROM AUTHOR]

Coral reefs are in global decline and anomalously hot temperatures shoulder the blame. Foraminferal bioindicators are important because they record historical reef stress over periods of centuries to millennia, as compared to the few decades offered by diver surveys. For a region lacking systematic long-term reef monitoring programs, the use of bioindicators in the Red Sea is compelling. Whereas foraminfera-based indices exist to reconstruct histories of nutrient stress on reefs, there is a paucity of equivalent bioindicators that respond to temperature. Capitalizing on a portfolio of surficial sediment samples collected along the eastern margin of the N. Red Sea and Gulf of Aqaba, this study shows that the relative abundance of Amphisteginidae foraminifera—specifically Amphistegina lobifera—closely track heat stress, as has recently been reported for this family in the S. Pacific. This result is consequential for at least three reasons. First, the Red Sea hosts some of the most northerly coral reefs on Earth. Establishment of a thermal bioindicator here confirms the strategy can be deployed on high latitudes reefs, which are disproportionally afflicted with heat extremes. Second, the considered reefs, and the foraminifera they host, are famed for their thermal resilience. Foraminiferal bioindicators have not previously been trialed on reefs that have adapted in this way. Finally, as a restricted offshoot of the Indian Ocean, the level of endemism in the Red Sea is especially high. The bioindicator that we propose is apparently not compromised by endemism. Our findings advocate for an expanded deployment of Amphistegina-based reef bioindicators. [ABSTRACT FROM AUTHOR]

We present an integrated, high-resolution, biostratigraphical, mineralogical, and geochemical characterization of the well-exposed Upper Paleocene - Lower Eocene stratigraphic succession of the Surghar Range (Baroch Nala section, NE Pakistan). The faunal assemblages from the Baroch Nala section, dominated by hyaline benthic foraminifera and green calcareous algae, along with the significant terrigenous fraction and the presence of terrestrially derived organic matter, testify to the deposition in a low-energy shallow-marine environment. Such environmental conditions, coupled with weak diagenetic effects, allow us to integrate a continuous record of carbon stable isotopes with a detailed account of the biotic response by carbonate-producing assemblages, paleoclimatic information based on clay-minerals, and information on volcanic activity based on mercury concentrations. The environmental evolution from the Late Paleocene up to the Paleocene Eocene Thermal Maximum (PETM) is clearly documented, including the weaker warm excursion that precedes the PETM (i.e. the Pre-Onset Excursion "POE"), and the evolution of large benthic foraminiferal assemblages. The overall record perfectly shows how the turnover in benthic carbonate producers started with the onset of the PETM and was completed by the time the excursion ended, highlighting how (geologically) brief environmental oscillations can have long lasting effects on the biosphere. • Paleocene-Eocene neritic carbonates record the PETM and POE events. • Hg-concentration, used as a proxy for volcanisms, are recorded along the section. • LBF assemblages show a major biotic turnover during the PETM. • Mineralogical composition indicates a hot and humid climate during PETM. • Similar patterns can be observed across the globe. [ABSTRACT FROM AUTHOR]

Reef-dwelling calcifiers face numerous environmental stresses associated with anthropogenic carbon dioxide emissions, including ocean acidification and warming. Photosymbiont-bearing calcifiers, such as large benthic foraminifera, are particularly sensitive to climate change. To gain insight into their responses to near-future conditions, Amphistegina lobifera from the Gulf of Aqaba were cultured under three pCO2 conditions (492, 963, 3182 ppm) crossed with two temperature conditions (28 °C, 31 °C) for two months. Differential protein abundances in host and photosymbionts were investigated alongside physiological responses and microenvironmental pH gradients assessed via proton microsensors. Over 1000 proteins were identified, of which > 15% varied significantly between treatments. Thermal stress predominantly reduced protein abundances, and holobiont growth. Elevated pCO2 caused only minor proteomic alterations and color changes. Notably, pH at the test surface decreased with increasing pCO2 under all light/dark and temperature combinations. However, the difference between [H+] at the test surface and [H+] in the seawater—a measure of the organism’s mitigation of the acidified conditions—increased with light and pCO2. Combined stressors resulted in reduced pore sizes and increased microenvironmental pH gradients, indicating acclimative mechanisms that support calcite test production and/or preservation under climate change. Substantial proteomic variations at moderate-pCO2 and 31 °C and putative decreases in test stability at high-pCO2 and 31 °C indicate cellular modifications and impacts on calcification, in contrast to the LBFs’ apparently stable overall physiological performance. Our experiment shows that the effects of climate change can be missed when stressors are assessed in isolation, and that physiological responses should be assessed across organismal levels to make more meaningful inferences about the fate of reef calcifiers.

The accelerated release of heavy metals into the coastal environments due to increasing anthropogenic activities poses a severe threat to local marine ecosystems and food chains. Although some heavy metals are essential nutrients for plants and animals, higher concentrations can be toxic and hazardous. To mitigate this threat, developing quantifiable proxies for monitoring heavy metal concentrations in near-shore marine environments is essential. Here, we describe culture experiments to quantify uptake of some heavy metals using live juvenile specimens of the large benthic foraminifera (LBF) Amphisorus hemprichii collected from the subtropical waters of Rottnest Island located ~20 km offshore Perth, South West Australia. The uptake of Mn, Ni, Cd, and Pb in the newly precipitated chambers of Amphisorus hemprichii in the laboratory was characterized using the micro-analytical technique, laser ablation inductively coupled plasma mass spectrometry. We found no significant increase in Mn, Ni, Cd, and Pb incorporation in the tests of Amphisorus hemprichii with increasing temperature and light intensities. Importantly, we found that changes in the concentrations of Mn, Ni, and Cd in the A. hemprichii tests are directly proportional to those in the culture solution over a wide range of concentrations. The calculated partition coefficients for Mn, Ni, and Cd from our culture experiments are 1.3±0.2, 0.3±0.04, 2.6±0.3, respectively. These multi-element calibration studies now enable A. hemprichii to be utilized as a naturally occurring bio-archive to quantitatively monitor the anthropogenic pollution of Mn, Ni, and Cd in coastal waters. [ABSTRACT FROM AUTHOR]

The aim of the work was to describe an assemblage of larger benthic foraminifers from quartz-glauconitic sandstones of the Bystrica Mb. of the Western Carpathian Magura Nappe. 21 samples of fine-grained conglomerates to fine-grained quartz-glauconitic sandstones were analysed from the Bystrica, Oravské Veselé and Lower Luhačovice Mbs. Tests of larger benthic foraminifers are mostly poorly preserved as a result of redeposition processes and weathering. The larger benthic foraminifer assemblages from the Orava region represent the early Eocene (Ilerdian to Cuisian), the middle Eocene (early to late Lutetian, SBZ 13 – 16) and in one case the middle Eocene (late Bartonian, SBZ 18). Age determination of the impoverished assemblage of larger benthic foraminifers from the Javorníky Mts. is early Eocene (late Ypresian – Cuisian) to middle Eocene (base of Lutetian).

Abstract Miscellaneidae is Paleogene larger index microfossils (middle Paleocene–early Eocene) that for determination of stratigraphic and palaeobiogeographic distributions are investigated in the Neo-Tethys Ocean. For biostratigraphic studies, depositional ages and systematic determinations of family Miscellaneidae, middle Paleocene–lower Eocene deposits in the Hormak section, in the north of Zahedan, are investigated. This stratigraphic section (470 meters) mainly consists of an alternation of marls, marly limestones, and limestones. Study of different miscellaneidae taxa led to identifications of Miscellanea miscella, Miscellanea juliettae, Miscellanites primitivus, and Miscellanites minutes that indicated standard biozone SBZ3–SBZ6 and therefore suggested late Paleocene–early Eocene age. Paleocene–Eocene boundary is identified with the appearance of Nummulitids and Alveolinids (SBZ5/6) in the western Neo-Tethys, whilst in the eastern Neo-Tethys these group of large benthic foraminiferas are absent. Some of Alveolina species accompanied by Glomalveolina, Miscellanea, and Ranikothalia species are seen which shows similarities between the Hormak section and other sections in the Indus basin and Tibet in the eastern Neo-Tethys. Based on biostratigraphic investigations, family Miscellaniedae, firstly appeared in SBZ1/2 in the western Neo–Tethys (Europe and Africa) whereas in the eastern Neo-Tethys (India, Tibet, and Pakistan) are not seen although the mentioned family in SBZ3/4 are recognized in the both western and eastern Neo-Tethys. In biozones SBZ5/6, SBZ7 and SBZ8, in the western Neo-Tethys family, Miscellaniedae disappeared whereas in the eastern Neo-Tethys are seen in the SBZ5/6 biozones. With respect to identified Miscellaniedae genus and species in the Hormak section and similarities with eastern Neo-Tethys, it seems that, with the omission of palaeoceanogrphic barrier in the Paleocene–Eocene boundary, the Miscellaniedae genus and species are migrated to the eastern Neo-Tethys. Keywords: Late Paleocene–early Eocene, Large Benthic Foraminifera, Sistan Suture Zone Introduction Large benthic foraminifera (LBF) are important fossils with large tests and complex internal structures. In biostratigraphic studies of Paleogene large benthic foraminiferas from Alveolina, Assilina (Hottinger 1960; Drobne 1977), and Nummulites (Schaub 1981) are used for introduction of 20 shallow benthic zones in the western Tethys (Serra-Kiel et al. 1998). Large benthic foraminiferas in the eastern and western Tethys similarly described but are different with regard to taxonomy (Hottinger 1971). The Paleocene of western Neo-Tethys are dominated with coralgal reefs (e.g. Accordi et al. 1998; Turnsek and Drobne 1998; Baceta et al. 2005; Scheibner et al. 2007) although in the eastern Neo-Tethys, the large benthic foraminiferas are dominated (Wan et al. 2002; Afzal et al. 2009, 2011; Zhang et al. 2013). Based on high biodiversity of Lockhartia in the Paleocene of Ronikot Formation in India, eastern Neo-Tethys ocean is named Ranikothalia Sea (Davies 1937) or Lockhartia Sea (Hottinger 1998) that occupied southern Turkey in the west to the Tibet and Pakistan in the east and Egypt in the south (Hottinger 2007, 2014). Another important aspect of large benthic foraminifera biodiversity is that the Lockhartia genus has a distinct chronostratigraphic position in the Paleocene resemble that Alveolina, Assilina, and Nummulites in the Eocene. For example, Lockhartia retiata Sander 1962 and Lockhartia praeheimi Smout 1954 are accepted as index fossils of the shallow benthic zone 3. The objectives of this study are the determination of stratigraphic importance and migration trend of Miscellaniedae family across the Tethys ocean in the late Paleocene–early Eocene time. Material & Method For LBFs biostratigraphic investigations of the Hormak section, in field studies, 100 rock specimens are collected and 350 thin sections are prepared from them for the study of different genus and species of Miscellaniedae family. The systematic determination of this group of large benthic foraminiferas is, in the level of genus and species, are done by using a binocular microscope and then based on identified LBFs, the age of the Hormak section is suggested. Discussion of Results & Conclusions In the eastern Neo-Tethys, SBZ3 and SBZ4 are identified with increasing generic diversity and reflect the time in which LBF have experienced the new morphology (Hottinger 2001; Scheibner and Speijer 2008). In India basin (eastern Neo-Tethys) the mentioned biozones are initiated with the appearance of new taxonomic trends such as Rothalids (Kathina and Lockhartia), Miliolids (Triloculina and Quinqueloculina) Pellatispirids (Miscellanea), Alveolinids (Glomalvelina), Coskinolinids (Coskinon), Spirocyclinids (Saudia), Dictyoconids (Fallotella, Dictyoconus), Nummulitids (Ranikothalia, Assilina, and Operculina) and Lepidorbitoids (Daviesina, Orbithosiphon, and Setia) (Afzal et al. 2009) that are correlatable with a faunistic scheme in the other part of the Tethys (Hottinger 1997, 1998; Jauhri 1998; Serra-Kiel et al. 1998; Jauhri and Agarwal 2001; Jauhri et al. 2006; Green et al. 2008; Scheibner and Speijer 2008, 2009; Zamagni et al. 2008; Mathur et al. 2009; Tewari et al. 2010). Studies of different genera of Miscellaneidae in the thin sections and isolated forms led to the identification of Miscellanea miscella, Miscellanea juliettae, Miscellanites primitivus, Miscellanits minutus that accompanied with other fossils are suggested the late Paleocene–early Eocene age. In the Hormak section, SBZ3 and SBZ4 biozones are identified with Kathina, Triloculina, Idalina, Quinqueloculina, Miscellanea, glomalveolina, Ranikothalia, and Discocyclina that in respect to abundance and diversity, correlatable with eastern Neo-Tethys foraminiferal assemblage (Afzal et al. 2009).

Abstract Concurrent anthropogenic global climate change and ocean acidification are expected to have a negative impact on calcifying marine organisms. While knowledge of biological responses of organisms to oceanic stress has emerged from single‐species experiments, these do not capture ecologically relevant scenarios where the potential for multi‐organism physiological interactions is assessed. Marine algae provide an interesting case study, as their photosynthetic activity elevates pH in the surrounding microenvironment, potentially buffering more acidic conditions for associated epiphytes. We present findings that indicate increased tolerance of an important epiphytic foraminifera, Marginopora vertebralis, to the effects of increased temperature (±3°C) and pCO2 (~1,000 µatm) when associated with its common algal host, Laurencia intricata. Specimens of M. vertebralis were incubated for 15 days in flow‐through aquaria simulating current and end‐of‐century temperature and pH conditions. Physiological measures of growth (change in wet weight), calcification (measured change in total alkalinity in closed bottles), photochemical efficiency (Fv/Fm), total chlorophyll, photosynthesis (oxygen flux), and respiration were determined. When incubated in isolation, M. vertebralis exhibited reduced growth in end‐of‐century projections of ocean acidification conditions, while calcification rates were lowest in the high‐temperature, low‐pH treatment. Interestingly, association with L. intricata ameliorated these stress effects with the growth and calcification rates of M. vertebralis being similar to those observed in ambient conditions. Total chlorophyll levels in M. vertebralis decreased when in association with L. intricata, while maximum photochemical efficiency increased in ambient conditions. Net production estimates remained similar between M. vertebralis in isolation and in association with L. intricata, although both production and respiration rates of M. vertebralis were significantly higher when associated with L. intricata. These results indicate that the association with L. intricata increases the resilience of M. vertebralis to climate change stress, providing one of the first examples of physiological buffering by a marine alga that can ameliorate the negative effects of changing ocean conditions.

Abstract Understanding the role of dispersal and adaptation in the evolutionary history of marine species is essential for predicting their response to changing conditions. We analyzed patterns of genetic differentiation in the key tropical calcifying species of large benthic foraminifera Amphistegina lobifera to reveal the evolutionary processes responsible for its biogeographic distribution. We collected specimens from 16 sites encompassing the entire range of the species and analyzed hypervariable fragments of the 18S SSU rDNA marker. We identified six hierarchically organized genotypes with mutually exclusive distribution organized along a longitudinal gradient. The distribution is consistent with diversification occurring in the Indo‐West Pacific (IWP) followed by dispersal toward the periphery. This pattern can be explained by: (a) high dispersal capacity of the species, (b) habitat heterogeneity driving more recent differentiation in the IWP, and (c) ecological‐scale processes such as niche incumbency reinforcing patterns of genotype mutual exclusion. The dispersal potential of this species drives the ongoing range expansion into the Mediterranean Sea, indicating that A. lobifera is able to expand its distribution by tracking increases in temperature. The genetic structure reveals recent diversification and high rate of extinction in the evolutionary history of the clade suggesting a high turnover rate of the diversity at the cryptic level. This diversification dynamic combined with high dispersal potential, allowed the species to maintain a widespread distribution over periods of geological and climatic upheaval. These characteristics are likely to allow the species to modify its geographic range in response to ongoing global warming without requiring genetic differentiation.

Global warming permits range expansions of tropical marine species into mid-latitude habitats, where they are, however, faced with cold winter temperatures. Therefore, tolerance to cold temperatures may be the key adaptation controlling zonal range expansion in tropical marine species. 2. Here we investigated the molecular and physiological response to cold and heat stress in a tropical symbiont-bearing foraminifera that has successfully invaded the Eastern Mediterranean. 3. Our physiological measurements indicate thermal tolerance of the diatom symbionts but a decrease in growth for the foraminifera host under both cold and warm stress. 4. The combined ('holobiont') transcriptome revealed an asymmetric response in short-term gene expression under cold versus warm stress. Cold stress induced major reorganization of metabolic processes, including regulation of genes involved in photosynthesis. Analyses limited to genes that are inferred to belong to the symbionts confirm that the observed pattern is due to changes in the regulation of photosynthesis-related genes and not due to changes in the abundance of the symbionts. 5. In contrast to cold stress, far fewer genes change expression under heat stress and those that do are primarily related to movement and cytoskeleton. This implies that under cold stress, cellular resources are allocated to the maintenance of photosynthesis, and the key to zonal range shifts of tropical species could be the cold tolerance of the symbiosis. [ABSTRACT FROM AUTHOR]

In tropical and sub‐tropical mixed siliciclastic–carbonate depositional systems, fluvial input and in situ neritic carbonate interact over space and time. Despite being the subject of many studies, controls on partitioning of mixed sediments remains controversial. Mixed sedimentary records, from Ashmore Trough shelf edge and slopes (southern Gulf of Papua), are coupled with global sea‐level curves and anchored to Marine Isotope Stage stratigraphy to constrain models of sediment accumulation at two different timescales for the past 130 kyr: (i) 100 kyr scale for last glacial cycle; and (ii) millennial scale for last deglaciation. During the last glacial cycle, carbonate production and accumulation were primarily controlled by sea‐level fluctuations. Export of neritic carbonate to the slopes was initiated during re‐flooding of previously exposed reefs and continued during Marine Isotope Stage 5e and 1 interglacial sea‐level highs. Siliciclastic fluxes to the slope were controlled by interplay of sea level, shelf physiography and oceanic currents. Heterogeneous accumulation of siliciclastic mud on the slope, took place during Marine Isotope Stage 5d to Marine Isotope Stage 3 sea‐level fall. Siliciclastics reached adjacent depocentres during Marine Isotope Stage 2. Coralgal reef and oolitic–skeletal sand resumed at the shelf edge during the subsequent stepwise sea‐level rise of the last deglaciation. Contemporaneous, abrupt siliciclastic input from increased precipitation and fluvial discharge illustrates that climate controlled deglacial sedimentation. Siliciclastic input persisted until ca 8.5 ka. Carbonate accumulation waned at the shelf edge after ca 14 ka, whereas it increased on the slopes since ca 11.5 ka, when previously exposed reef and bank tops were re‐flooded. When comparing the last sea‐level cycle sedimentation patterns of the southern Gulf of Papua with other coeval mixed systems, sea level and shelf physiography emerge as primary controls on deposition at the 100 kyr scale. At the millennial scale, siliciclastic input was also controlled by climate change during the unstable atmospheric and oceanic conditions of the last deglaciation. [ABSTRACT FROM AUTHOR]

Abstratct Miscellaneidae are Paleogene larger index microfossils (Middle Paleocene–Early Eocene) that are important for biozonation of shallow marine deposits. These large benthic foraminifera have distinct architecture and ornamentation schemes which differentiated them form Nummulitidae and Rotalidae families. Miscellaneidae have different taxa that essentially are usefulness for biostratigraphic and palaeobiogeographic investigations. For biostratigraphic studies, age and systematic determinations of miscellaneidae, Middle Paleocene–lower Eocene deposits of two outcrop sections are investigated in the Padagi village in the north of Zahedan. These stratigraphic sections mainly consist of alternation of marls, marly limestones and limestones with 237.5 m thickness for PE section and 222.5 m thickness for PEP section. Study of different Misellaneidae genera led to identifications of Miscellanea miscella, Miscellanea juliettae, Miscellanites primitives and Miscellanites minutus that shows standard biozone SBZ3–-SBZ6 and therefore suggested Late Paleocene–-Early Eocene age. Moreover, global distribution patterns of older species of Miscellaneidae represents that these species belong to the eastern Tethys basin. Keywords: Late Paaleocene–Early Eocene, Large Benthic Foraminifera, Sistan Suture Zone Introduction: Large benthic foraminifera (LBF) are important fossil and extant forms that in respect to systematic and biostratigraphy, extensively are studied and some biozonation schemes based on them are suggested. This group of foraminifera shows rapid diversification events and sudden extinctions in the geological history (Hallock 1985). Development and occurrence of them related to the warming period, relative dryness, sea level rising, development of tropical and sub-tropical habitats and decreasing of oceanic cycles in the global scale (Hallock and Glenn 1986). In the Early Cenozoic, Nummulitids (Nummulites, Assilina and Operculina), Orthophragminids (Discocyclina) and Alveolinids (Alveolina) are LBFs that distributed in the shallow water oligotrophic environments in the Tethys ocean and are one of the most important carbonate producers in the inner and middle ramp environments (Bouxton and Pedley 1989). Therefore in the eastern Tethys, LBFs such as Miscellanea and Ranikothalia are found in the Early Eocene of carbonate platforms, whilst Alveolina are less important and Nummulites is not found (Scheibner and Speijer 2008a). In addition, in the other part of Tethys ocean genera such as Miscellanea and Ranikothalia, after Paleocene–Eocene boundary accompanied with Nummulites and Alveolina assemblages are found. In Paleocene and Eocene of the Tethys basin LBF biozonation are represented by Sarra-Kiel et al. (1998) which based on these group of foraminifera Paleocene and Eocene series are divided into 20 shallow benthic zones (SBZ1–-SBZ20). The boundary between Paleocene and Eocene is considered between SBZ4–-SBZ5 (Scheibner and Speijer 2009). Miscellaneidae are an index microfossils that are very important group for zonation of Middle Paleocene and earliest Eocene shallow marine deposits. Miscellaneidae family have different genera and species that are used for biostratigraphic and paleobiogeographic studies. Material & Methods: For LBFs biostratigraphic investigations of Padagi section, 125 rock specimens are collected and 580 thin section are prepared. The systematic determination of foraminifera, in level of genus and species, are done by using of binocular microscope and then based on identified LBFs, the age of the succession is suggested. Discussion of Results & Conclusions: Studies of different genera of Miscellaneidae in the thin sections and isolated forms led to identification of Miscellanea miscella، Miscellanea juliettae،Miscellanites primitivusMiscellanits minutus that accompanied with other fossils are suggested the Late Paleocene–Early Eocene age. Miscellanea miscella in Salt Range, Egypt and Aquitaine (south western of France) appearance in the SBZ4 (Late Thanetian) and continued up to SBZ6. Zhang et al. (2013, 2018) has reported Miscellanea miscella from SBZ5/6 in the Tibet area (eastern Tethys). In Padagi section, this species is found accompanied with Ranikothalia nuttali, Assilina dandotica, Discocyclina sella and D. Ranikotensis, which shows SBZ4 and in thSBZ5/6 and suggested Late Paleocene–Early Eocene age. Existence of Miscellanea juliettae, Vania anatolica, Miscellanites primitivus and Glomalveolina primaeva in the lower part of the Padagi section shows SBZ3 biozone and Late Paleocene (Early Thanetian) age. This fossils assemblge belong to the SBZ3–SBZ6 standard biozones that with respect to Miscellanea miscella distribution pattern and accompanied with Miscellanites and Ranikothalia and absence of earliest Eocene benthic foraminiferas such as Nummulites, Alveolina and Ranikothalia in the Padagi section shows that the mentioned species belong to the eastern Tethys which has migrated to the younger time horizons to the western Tethys. In Iran, different species of Miscellanea and Miscellanites in the Taleh-Zang Formation, Zagros Mountain, Shiraz and Sistan basin (Rahaghi 1983) are reported. In the Tibet area differentiation and diversity of genera and species, primary dimorphism and adult size of shell of LBFs such as Keramosphaerinopsis haydeni (SBZ3), Daviesina langhami (SBZ4–5), Miscellanea miscella (SBZ5) refer to, probably, Paleocene LBFs more faster and quickly has evolved relative to the western part of the Tethys and shows that LBF turnover (LFT), in the eastern part has happened earlier in time (Zhang et al. 2013, 2018). With respect to the abundance and development of the Ranikothalids and Miscellanids and absence of Alveolinid genera and species in the SBZ5/6 biozones and similarities of foraminiferal assemblage indicated that the Padagi section and Late Paleocene–Early Eocene sediments are deposited in eastern part of the Tethys in the north of Zehedan. Abscene of Nummulites and Alveolina genera in Early Eocene time fascinate the survival of these genera in the eastern Tethys. In the other part of the Tethys, especially western Tethys, the Paleocene LBFs, totally replaced with Nummulites, Alveolina and Assilina genera (Orue-Etxebarria et al. 2001). With regards to affinity and similarity of LBF assemblages (widespread of Ranikothalia and Miscellanea and absence of Nummulites and Alveolina genera in the SBZ5 and SBZ6) of Sistan basin (Padagi section) with Indus basin (in Pakistan and India) concluded that, palaeobiogeographically, the mentioned basin are related to the eastern part of the Tethys.

Concurrent anthropogenic global climate change and ocean acidification are expected to have a negative impact on calcifying marine organisms. While knowledge of biological responses of organisms to oceanic stress has emerged from single‐species experiments, these do not capture ecologically relevant scenarios where the potential for multi‐organism physiological interactions is assessed. Marine algae provide an interesting case study, as their photosynthetic activity elevates pH in the surrounding microenvironment, potentially buffering more acidic conditions for associated epiphytes. We present findings that indicate increased tolerance of an important epiphytic foraminifera, Marginopora vertebralis, to the effects of increased temperature (±3°C) and pCO2 (~1,000 µatm) when associated with its common algal host, Laurencia intricata. Specimens of M. vertebralis were incubated for 15 days in flow‐through aquaria simulating current and end‐of‐century temperature and pH conditions. Physiological measures of growth (change in wet weight), calcification (measured change in total alkalinity in closed bottles), photochemical efficiency (Fv/Fm), total chlorophyll, photosynthesis (oxygen flux), and respiration were determined. When incubated in isolation, M. vertebralis exhibited reduced growth in end‐of‐century projections of ocean acidification conditions, while calcification rates were lowest in the high‐temperature, low‐pH treatment. Interestingly, association with L. intricata ameliorated these stress effects with the growth and calcification rates of M. vertebralis being similar to those observed in ambient conditions. Total chlorophyll levels in M. vertebralis decreased when in association with L. intricata, while maximum photochemical efficiency increased in ambient conditions. Net production estimates remained similar between M. vertebralis in isolation and in association with L. intricata, although both production and respiration rates of M. vertebralis were significantly higher when associated with L. intricata. These results indicate that the association with L. intricata increases the resilience of M. vertebralis to climate change stress, providing one of the first examples of physiological buffering by a marine alga that can ameliorate the negative effects of changing ocean conditions. [ABSTRACT FROM AUTHOR]

"Larger" foraminifera appear in different lineages through the evolutionary history of the group. Traditionally, the reason why benthic forams of calcareous wall--mainly milliolids and rotallids--reached centimetric dimensions was attributed to the endosymbiotic relationships with algae. The ecological requirements and morphological characteristics of tests are known from experimental studies in extant forms. These requirements and characteristics are fundamental to establish and maintain symbiosis with diverse chlorophytes, rhodophytes, diatoms, dinoflagellates and cyanobacteria groups. Such relationships are neither exclusive or a sine qua non condition for larger taxa. This work aims to explore the published literature regarding this topic in order to sort out how experimental and palaeontological evidences can be of use to infer symbiotic relationships on the fossil record. [ABSTRACT FROM AUTHOR]

Understanding the role of dispersal and adaptation in the evolutionary history of marine species is essential for predicting their response to changing conditions. We analyzed patterns of genetic differentiation in the key tropical calcifying species of large benthic foraminifera Amphistegina lobifera to reveal the evolutionary processes responsible for its biogeographic distribution. We collected specimens from 16 sites encompassing the entire range of the species and analyzed hypervariable fragments of the 18S SSU rDNA marker. We identified six hierarchically organized genotypes with mutually exclusive distribution organized along a longitudinal gradient. The distribution is consistent with diversification occurring in the Indo‐West Pacific (IWP) followed by dispersal toward the periphery. This pattern can be explained by: (a) high dispersal capacity of the species, (b) habitat heterogeneity driving more recent differentiation in the IWP, and (c) ecological‐scale processes such as niche incumbency reinforcing patterns of genotype mutual exclusion. The dispersal potential of this species drives the ongoing range expansion into the Mediterranean Sea, indicating that A. lobifera is able to expand its distribution by tracking increases in temperature. The genetic structure reveals recent diversification and high rate of extinction in the evolutionary history of the clade suggesting a high turnover rate of the diversity at the cryptic level. This diversification dynamic combined with high dispersal potential, allowed the species to maintain a widespread distribution over periods of geological and climatic upheaval. These characteristics are likely to allow the species to modify its geographic range in response to ongoing global warming without requiring genetic differentiation. [ABSTRACT FROM AUTHOR]

The development history of an oligo-mesophotic, early Miocene, isolated carbonate system (>160 m in thickness), forming the uppermost part of the Oligo-Miocene Yadana buildup (northern Andaman Sea), has been evidenced from the integration of sedimentological core studies from 4 wells (cumulated core length: 343 m), well correlations, seismic interpretation and analysis of the ecological requirements of the main skeletal components. Three types of carbonate factory operated on the top of the platform, depending on water-depth, turbidity and nutrient level: (1) a scleractinian factory developing under mesophotic conditions during periods of high particulate organic matter supplies, (2) an echinodermal factory occupying dysphotic to aphotic area of the platform coevally with the scleractinian factory, (3) a large benthic foraminiferal-coralline algal factories prevailing under oligo-mesophotic and oligo-mesotrophic conditions. The limited lateral changes in facies between wells, together with the seismic expression of the Yadana buildup, suggest deposition on a flat-topped shelf. Carbonate production and accumulation on the Yadana platform was mainly controlled by light penetration, nutrient content and hydrodynamic conditions. Scleractinian-rich facies resulted from transport of coral pieces derived from mesophotic environments (mounds?) and deposited in deeper, low light , mud-rich environments in which lived abundant communities of suspension feeders such as ophiuroids. Changes in monsoonal intensity, terrestrial runoff from the Irrawaddy River, upwelling currents and internal waves activity during the early Miocene are likely responsible for significant variations in water turbidity and nutrient concentration in the Andaman Sea, thus promoting the development of an oligo-mesophotic, incipiently drowned platform. • An oligo-mesophotic isolated carbonate platform developed during the early Miocene. • Coral-rich deposits are related to mesophotic carbonate production. • Cycles of particulate organic matter influx are recorded in carbonate sedimentation. • Internal waves, upwellings and terrigenous supplies controlled carbonate production. [ABSTRACT FROM AUTHOR]

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During the Eocene, shallow-water carbonate systems were significantly impacted by climate fluctuations and hyperthermal events. Following the peak temperatures of the Early Eocene Climatic Optimum (EECO), a general cooling trend began, with short-lived (⁓200 kyr) warming events occurring alongside it. In the early Bartonian (around 40.1 Ma), a warming event known as the Middle Eocene Climatic Optimum (MECO) occurred, lasting approximately 500,000 years. In this scenario, the types and calcification rates of marine organisms such as corals and larger benthic foraminifera (LBF) were influenced by global CO 2 and oceanographic changes, which had a major effect on photic carbonate factories. To better understand the effects of these factors on carbonate factories, a detailed study of shallow-water facies types, distributions, and evolution was conducted. The Middle Eocene Monte Saraceno sequence, located on the eastern margin of the Apulia Carbonate Platform (Gargano Promontory, southern Italy), was selected as a case study to investigate the relationships between carbonate factory types and climatic changes around the MECO event. This study identified two distinct intervals with different modes of carbonate production, separated by a sharp boundary. The lower interval consists of clinostratified, thick beds of rudstone to floatstone, mostly made up of various large Nummulites tests, indicating an early Bartonian age (Shallow Benthic Zone 17). Instead, the upper interval consists of coral floatstone to rudstone with a packstone matrix, rich in branching corals in association with gastropods, bivalves, and rare small larger benthic foraminifera. The appearance of Heterostegina sp. and Glomalveolina ungaroi in this interval indicates a late Bartonian age (Shallow Benthic Zone 18). By integrating biostratigraphic and stable-isotope data, the lower interval, with abundant Nummulites , was linked to the MECO event, during which higher sea-surface temperatures seem to enhance larger benthic foraminifera proliferation, as already occurred in the Early Eocene. However, in the late Bartonian, the sharp transition to a coral-dominated carbonate factory, with rare larger benthic foraminifera showing smaller sizes, could be attributed to a drop in temperature that created the conditions more favourable to corals. Overall, this study provides compelling evidence of how environmental changes can affect marine carbonate production, also highlighting the importance of investigating these relationships, to better understand climate change in the past, present and near future. • Eocene shallow-water carbonate systems were influenced by hyperthermal events. • Environmental changes can significantly impact marine carbonate production. • Larger benthic foraminifera flourished during the Middle Eocene Climatic Optimum. • The coral-dominated carbonate factory shift was attributed to a drop in temperature. [ABSTRACT FROM AUTHOR]

Because reef-dwelling large benthic foraminifera (LBF) tests, which is composed of high-magnesium calcite, are the common components of modern reef sediments, and ancient reef carbonate rocks, they can provide a continuous record of the paleoenvironment of reef sediments. Evaluation of the responses of the minor element concentrations (Mg, Sr, Na, P, and S) of individual tests to ambient temperature and LBF growth modes was conducted with two cultured species, Calcarina gaudichaudii and Amphisorus kudakajimensis. The elements were assessed as tracers of temperature, salinity, nutrient concentration, and calcification rate. The Mg content of C. gaudichaudii and the Sr content of both species were controlled by temperature. It can be confirmed that the Mg of individual tests of C. gaudichaudii is a useful paleothermometer. There was a large biological modulation of Na, P, and S incorporation. In situ XANES analysis revealed that both inorganic and organic species contributed to the P and S content of LBF tests. We observed five sulfur components with variable oxidation states.

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Adaptation, acclimatization and symbiont diversity are known to regulate thermal tolerance in corals, but the role of these mechanisms remains poorly constrained in other photosymbioses, such as large benthic foraminifera (LBFs), which are known to bleach at temperatures that are likely to be exceeded in the near future. LBFs inhabit a broad range of shallow-water settings. Within species, differences in thermal tolerance have been found among populations from different habitats, but it is not clear whether such differences occur among LBFs inhabiting similar habitats, but differing in other aspects, such as symbiont type. To this end, we compared responses to thermal stress in specimens from a population of Amphistegina lessonii, an abundant Indo-Pacific species, to specimens of Amphistegina gibbosa, its Atlantic counterpart, from a similar environment but two different water depths (5 and 18 m). Test groups of each species were exposed in a common experiment to three thermal stress scenarios over a four-week period. Growth, respiration, mortality and motility were measured to characterize the holobiont response. Coloration, photosynthesis and chlorophyll a content were measured to determine the response of the endosymbiotic diatoms. The photosymbionts were characterized by genetic fingerprinting. Our results show that, although groups of A. gibbosa were collected from different habitats, their responses were similar, indicating only marginally higher tolerance to thermal peaks in specimens from the shallower site. In contrast, species-specific differences were stronger, with A. lessonii showing higher tolerance to episodic stress and less pronounced impacts of chronic stress on motility, growth and photosymbiont performance. These interspecies variations are consistent with the presence of different and more diverse symbiont assemblages in A. lessonii compared with A. gibbosa. This study demonstrates the importance of considering symbiont diversity in the assessment of intra- and interspecific variations in stress responses in LBFs. [ABSTRACT FROM AUTHOR]

Sediment transport is a key driver of reef zonation and biodiversity, where an understanding of sediment dynamics gives insights into past reef processes and allows the prediction of geomorphic responses to changing environmental conditions. However, modal conditions within the back-reef seldom promote sediment transport, hence direct observation is inherently difficult. Large benthic foraminifera (LBF) have previously been employed as ‘tracers’ to infer sediment transport pathways on coral reefs, as their habitat is largely restricted to the algal flat and post-mortem, their calcium carbonate test is susceptible to sediment transport forces into the back-reef. Foraminiferal test abundance and post-depositional test alteration have been used as proxies for sediment transport, although the resolution of these measures becomes limited by low test abundance and the lack of variation within test alteration. Here we propose the novel use of elemental ratios as a proxy for sediment transport. Two species, Baculogypsina sphaerulata and Calcarina capricornia , were analysed using a taphonomic index within One Tree and Lady Musgrave reefs, Great Barrier Reef (Australia). Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine Mg/Ca and Sr/Ca and these ratios were compared with taphonomic data. Decreases in test Mg/Ca accompany increases in Sr/Ca in specimens from algal-flat to lagoonal samples in both species, mirroring trends indicated by taphonomic values, therefore indicating a relationship with test alteration. To delineate mechanisms driving changes in elemental ratios, back-scattered electron (BSE) images, elemental mapping and in situ quantitative spot analyses by electron microprobe microanalysis (EPMA) using wavelength dispersive X-ray spectrometers (WDS) were performed on un-altered algal flat and heavily abraded tests for both species. EPMA analyses reveal heterogeneity in Mg/Ca between spines and the test wall, implying the loss of appendages results in a decrease in Mg/Ca. BSE imaging and WDS elemental mapping provided evidence for cementation, facilitated by microbial-boring as the primary cause of increasing Sr/Ca. These novel proxies hold advantages over taphonomic measures and further provide a rapid method to infer sediment transport pathways within back-reef environments. [ABSTRACT FROM AUTHOR]

Fellowes, T.E.; Gacutan, J.; Harris, D.L.; Vila-Concejo, A.; Webster, J.M., and Byrne, M., 2017. Patterns of sediment transport using foraminifera tracers across sand aprons on the Great Barrier Reef. Sediment dynamics exert large control over coral reef geomorphological evolution and are vital to understanding past and present geomorphic responses. Large benthic foraminifera (LBF) live in the algal reef flats, and their tests (shells) are transported post-mortem by waves and currents onto back-reef environments, including sand aprons. This study investigated the patterns of transport linking surficial and downcore sediments in samples from three sand aprons with different wave exposures at One Tree Reef on the southern Great Barrier Reef (Australia). Six LBF genera represented up to 32% of the sediments analysed. Lagoonward transport increased LBF test abrasion and sediment bulk density. Sediment grain size and LBF abundance in sediments also decreased with lagoonward transport. Sediment transport patterns indicated by LBF species used as tracer were consistent with the prominent E-SE wave environment. A novel taphofacies approach was used to describe stratigraphic layers in downcore sediments based on LBF test abrasion and abundance. Varied sediment deposition rates did not affect the LBF test abrasion signature downcore. It appears that Baculogypsina sphaerulata has been the dominant species for at least 3 ka. Tests that were deposited slowly exhibited less or the same levels of abrasion than those that were rapidly deposited. It appears that test abrasion is primarily determined by the distance travelled rather than the influence of increased age or chemical dissolution. [ABSTRACT FROM AUTHOR]

Different Miocene shallow-water carbonate successions have been examined to test the potential of phosphorus sequential extraction (SEDEX) in studying palaeo-nutrient levels, and to investigate nutrient influence on carbonate-factories during this epoch. The coralline-algal-dominated sequence of the Pietra da Cantoni Group (NW Italy) and the bryozoan-dominated sequence of the Sommières Basin (S France), have been targeted for this study. Actually, albeit they both developed during the Burdigalian, in the very same latitudinal zone, they present remarkably different carbonate factories. Palaeontological analyses have investigated the distribution of the major groups of carbonate-producing organisms throughout the successions. These results have been compared with those of geochemical analyses on phosphorus and organic matter abundance, testifying a clear relationship between the skeletal assemblage and the availability of nutrients. As expected on the basis of modern oceanography and benthic ecology, bioavailable phosphorus concentration was higher in the bryozoan-dominated basin than in the coralline-algal-dominated basin. This result strongly supports SEDEX sequential extraction as a viable instrument to investigate the nutrient supply in the geological record. This also proves that the early-Miocene Mediterranean carbonate-factories were deeply controlled by nutrient influence, with patterns similar to those observed in present-day oceans. Moderate nutrient-concentrations resulted in coralline-algal dominance, while high nutrient-concentrations produced carbonate factories dominated by heterotrophs suspension-feeders like bryozoans. The euphotic-zone producers, which dominate in classical tropical associations, were probably restricted to areas with low nutrient-concentrations. [ABSTRACT FROM AUTHOR]

Large benthic foraminifera (LBF) are prolific producers of calcium carbonate sediments in shallow, tropical environments that are being influenced by ocean acidification (OA). Two LBF species, Amphistegina gibbosa (Order Rotaliida) with low-Mg calcite tests and Archaias angulatus (Order Miliolida) with high-Mg calcite tests, were studied to assess the effects of pH 7.6 on oxygen and carbon isotopic fractionation between test calcite and ambient seawater. The δ18O and δ13C values of terminal chambers and of whole adult tests of both species after 6 weeks were not significantly different between pH treatments of 8.0 and 7.6. However, tests of juveniles produced during the 6-week treatments showed significant differences between δ18O and δ13C values from control (pH 8.0) when compared with the treatment (pH 7.6) for both species. Although each individual's growth was photographed and measured, difficulty in distinguishing and manually extracting newly precipitated calcite from adult specimens likely confounded any differences in isotopic signals. However, juvenile specimens that resulted from asexual reproduction that occurred during the experiments did not contain old carbonate that could confound the new isotopic signals. These data reveal a potential bias in the design of OA experiments if only adults are used to investigate changes in test chemistries. Furthermore, the results reaffirm that different calcification mechanisms in these two foraminiferal orders control the fractionation of stable isotopes in the tests and will reflect decreasing pH in seawater somewhat differently. [ABSTRACT FROM AUTHOR]

Large benthic foraminifera (LBFs) are a vital component of coral reef carbonate production, often overlooked due to their small size. These super-abundant calcifiers are crucial to reef calcification by generation of lagoon and beach sands. Reef-scale carbonate production by LBFs is not well understood, and seasonal fluctuations in this important process are largely unquantified. The biomass of five LBF species in their algal flat habitat was quantified in the austral winter (July 2013), spring (October 2013), and summer (February 2014) at One Tree Reef. WorldView-2 satellite images were used to characterize and create LBF habitat maps based on ground-referenced photographs of algal cover. Habitat maps and LBF biomass measurements were combined to estimate carbonate storage across the entire reef flat. Total carbonate storage of LBFs on the reef flat ranged from 270 tonnes (winter) to 380 tonnes (summer). Satellite images indicate that the habitat area used by LBFs ranged from 0.6 (winter) to 0.71 km (spring) of a total possible area of 0.96 km. LBF biomass was highest in the winter when algal habitat area was lowest, but total carbonate storage was the highest in the summer, when algal habitat area was intermediate. Our data suggest that biomass measurements alone do not capture total abundance of LBF populations (carbonate storage), as the area of available habitat is variable. These results suggest LBF carbonate production studies that measure biomass in discrete locations and single time points fail to capture accurate reef-scale production by not incorporating estimates of the associated algal habitat. Reef-scale measurements in this study can be incorporated into carbonate production models to determine the role of LBFs in sedimentary landforms (lagoons, beaches, etc.). Based on previous models of entire reef metabolism, our estimates indicate that LBFs contribute approximately 3.9-5.4% of reef carbonate budgets, a previously underappreciated carbon sink. [ABSTRACT FROM AUTHOR]

Larger benthic foraminifera (LBF) are important and prolific carbonate producers both in modern and ancient shallow tropical seas. During the Paleogene the genus Nummulites was particularly abundant with a global distribution, leading it to be frequently used in biostratigraphy. However, their evolution is poorly understood as classification is Europe-centered and mostly based on external characters and equatorial thin sections. New occurrences from regions outside the northern Tethys which poorly fit in thus reference frame, show that a more rigid framework for the classification of Nummulites is needed. Here we apply micro computed-tomographical scanning, a tool that recently has become available, to visualise 3D chamber shape of Nummulites djokdjokartae and compare these to traditional morphometrical characters. We find that despite the regular shape in equatorial and axial thin section the irregular 3D chamber shape is not predicted by these sections. We argue that 3D reconstructions of Nummulites tests will be a great aid in improving our understanding of lineages within the genus Nummulites, and to elucidate its evolutionary and biogeographical history.

The Late Eocene-Oligocene-Early Miocene sequences of the Kurdistan foreland basin, considered as an important shallow, thick oil and gas reservoir in Kurdistan region/N-Iraq. Several diverse larger foraminifera ( Alveolina, Orbitolites, Assilina, Archaias, Austrotrillina, Miogypsinoide, Nummulites, Operculina, Borelies, and Lepdicyclina) with important stratigraphic, paleo-ecological, and palaeo-biogeographical implications are described with respect to its position in the Neo-Tethys basin. The biozonation, using large benthonic foraminifera, leads to the reconstruction of the chronostratigraphic framework. For that purpose, more than 367 samples from six wells and twelve outcrops, from different tectonic domains, within Zagros fold-thrust belt were analyzed. Almost four sequence boundaries (SB) segmented the depositional sequences into three third-order sequences. The lower most sequence boundary was estimated to be of Bartonian age (37 Ma) that represents by more than 5-m conglomerates between the molasses facies of the Gercus and carbonates of the Pila Spi Formations. The second sequence boundary, known as Zagros Major Hiatus, was estimated to be of the age 34 Ma and was placed at the top of karstfied carbonates of the Pila Spi Formation (Pribonian), directly below the Fatha Formation (Burdigalian-Langhian) almost manifesting the boundary between Tectonomegasequence AP10 and AP11. The third one is almost between the Rupelian and the Chattian (28 Ma) within Kirkuk Group. The last recorded one of Aquitanian age (21 Ma) was placed between the Kirkuk Group and Jeribe or Euphrates Formations. The three third-order depositional sequences were recognized from deepening and shallowing trends in the depositional facies, stacking patterns, and sequence boundary features. The first third-order represents the Late Eocene sequence (Pila Spi-shelf facies latterly change to Avanah-Jaddala Formations-depocenter facies), the second one represents the Rupelian-Chattian-Early Aquitanian third order in which each of the lower cycle of the Kirkuk Group (Rupelian) and the upper sequence of the Kirkuk Group (Chattian-Early Aquitanian) represents a fourth-order sequence. The last third order manifests by the Late Aquitanian-Early Burdigalian sequence of the Euphrates shelf facies that is changed laterally to Serikagni depocenter facies and mostly change upwards to Jeribe Formation. The lateral and vertical facial changes point to the increasing of the sequence thicknesses from the high folded thrust zone towards the low folded thrust zone and across the transversal Khanqain fault. The carbonate depositional ramp mostly segmented into isolated highs (occasionally separated from the palaeo-shorelines), that are either due to the influence of the thrust propagation deformational front or reactivation of the deep cited faults. [ABSTRACT FROM AUTHOR]