RECENT PUBLICATIONS ON FORAMINIFERA 2012 (1)
MESSINIAN PALEOENVIRONMENTAL EVOLUTION BASED ON BENTHIC FORAMINIFERA
Benthic foraminiferal assemblages of a drill core from the lower Guadalquivir Basin (SW Spain) have been analyzed in order to reconstruct the paleoenvironmental evolution in the vicinity of the Betic seaways during the Messinian. Changes in the abundance of certain marker species, planktonic/benthic ratio (P/B ratio), paleodepth estimated with a transfer function, content of sand grains and presence of glauconitic layers indicate a complete transgressive–regressive sea-level cycle from the bottom to the top of the section. An abrupt sea-level rise, from inner-middle shelf to middle slope, is recorded at the lowermost part of the core (latest Tortonian–earliest Messinian), followed by a relatively rapid shallowing from middle slope to outer shelf. Magnetobiostratigraphic data show that this sea-level fall postdates the onset of the Messinian salinity crisis (MSC) in the Mediterranean. Finally, the early Pliocene deposits are interpreted as inner-middle shelf. Changes in the benthic foraminiferal assemblages are mainly controlled by the trophic conditions, specifically by the quantity and quality of the organic matter reaching the sea floor. The upper slope and part of the outer shelf assemblages are highly diverse and dominated by shallow infaunal species, indicating a generally mesotrophic environment with moderate oxygenation. These environments have likely been affected by repeated upwelling events, documented by increased abundance of Uvigerina peregrina s.l., an opportunistic species thriving in environments with enhanced labile organic matter supply. The assemblages of the transitional interval between upper slope to outer shelf, and of the outer shelf are generally characterized by a relatively low diversity and epifaunal-shallow infaunal taxa, indicating oligotrophic and well-oxygenated conditions. The inner-middle shelf assemblages are characterized by very low diversity and dominance of intermediate to deep infaunal taxa, suggesting an eutrophic environment with low oxygen content. These assemblages are dominated by Nonion fabum and Bulimina elongata, two taxa that are able to feed from continental low-quality organic matter,most likely derived from river run-off. (ABSTRACT)
Pérez-Asensio, J.N., Aguirre, J., Schmiedl, G., Civis, J., 2012. Messinian paleoenvironmental evolution in the lower Guadalquivir Basin (SW Spain) based on benthic foraminifera. Palaeogeography, Palaeoclimatology, Palaeoecology 326-328, 135-151.
THE MEANING OF BIRTH AND DEATH - CASE STUDY WITH PLANKTIC FORAMINIFERA
Birth–death models are central to much macroevolutionary theory. The fundamental parameters of these models concern durations. Different species concepts realize different species durations because they represent different ideas of what birth (speciation) and death (extinction) mean. Here, we use Cenozoic macroperforate planktonic foraminifera as a case study to ask: what are the dynamical consequences of changing the definition of birth and death? We show strong evidence for biotic constraints on diversification using evolutionary species, but less with morphospecies. Discussing reasons for this discrepancy, we emphasize that clarity of species concept leads to clarity of meaning when interpreting macroevolutionary birth–death models. (ABSTRACT)
Ezard, T.H.G., Pearson, P.N., Aze, T., Purvis, A., 2012. The meaning of birth and death (in macroevolutionary birth–death models. biology letters 8 (1), 139--142.
GLOBAL DECLINE IN OCEAN VENTILATION AND PRODUCTIVITY DRUING THE PETM
The prominent global warming event at the Paleocene-Eocene boundary (55 Ma), referred to as the Paleocene-Eocene Thermal Maximum (PETM), was characterized by rapid temperature increase and changes in the global carbon cycle in <10,000 yr, and a major extinction of benthic foraminifera. We explore potential causes of this extinction in response to environmental changes linked to a massive carbon injection by comparing sedimentary records with results from a comprehensive climate–carbon cycle model, and infer that an increase in oceanic vertical temperature gradients and stratification led to decreased productivity and oxygen depletion in the deep sea. ...... The extinction of deep-sea benthic foraminifera at the PETM thus was probably caused by multiple environmental changes, including decreased carbonate saturation and ocean acidification, lowered oxygen levels, and a globally reduced food supply, all related to a massive carbon injection. (ABSTRACT)
Winguth, A.M.E., Thomas, E., Winguth, C., 2012. Global decline in ocean ventilation, oxygenation, and productivity during the Paleocene-Eocene Thermal Maximum: Implications for the benthic extinction. Geology, doi: 10.1130/G32529.1
INTRASPECIFIC VARIATION IN TRIASSIC OPHTHALMIDIIDS FROM TIMOR
Four ophthalmidiid species are described as free specimens extracted from mudstones and wackestones of Triassic age: Atsabella bandeiraensis nov. gen. nov. sp., Karaburunia atsabensis nov. sp., Ophthalmidium sp. cf. O. primitivum Ho and Spirophthalmidium grunaui nov. sp. Analysis of morphological variation found in large suites of specimens suggests that, as in modern miliolids, apertural characteristics, chamber shape and adult test size are features that vary within narrow limits and may be used to define species. ...... In Timor Leste, A. bandeiraensis, K. atsabensis and S. grunaui have been found with conodonts indicative of the Carnian, but the full local stratigraphic range of these species is uncertain. K. atsabensis occurs at another locality with conodonts suggestive of the Middle Triassic or less likely Carnian. Ophthalmidium sp. cf. O. primitivum has been found at one locality associated with A. bandeiraensis and K. atsabensis in a stratigraphic succession that suggests a correlation to the Carnian or Norian. The ophthalmidiids are found commonly associated with organic-cemented agglutinated and hyaline foraminifera and at some localities common to abundant ostracods and mollusc debris. They were most common in organic-rich carbonate mud of shallow-marine environments. (ABSTRACT)
Haig, D.W., McCartain, E., 2012. Intraspecific variation in Triassic Ophthalmidiid Foraminifera from Timor. Revue de Micropaléontologie, doi:10.1016/j.revmic.2011.12.001
INFLUENCE OF TEST SIZE, WATER DEPTH AND ECOLOGY ON Mg/Ca, Sr/Ca, δ18O and δ13C
Mg/Ca palaeothermometry in foraminiferal calcite is a widely applied tool in palaeoceanography. However, our understanding of the effects of planktic foraminiferal ecology and early diagenesis on test calcite Mg/Ca is limited. Here we report results of a study designed to shed new light on ecological, size-related and very early (water column) diagenetic controls on Mg/Ca in planktic foraminiferal calcite. We analysed Mg/Ca and stable isotopes of nine modern planktic foraminiferal species across fourteen mostly 50 μm-window sieve fractions in a core-top sample from the North Atlantic Ocean. We also analysed Mg/Ca in four of these nine species from plankton-tow samples collected from 0 to 2500 m water depth in the North Atlantic Ocean and Arabian Sea.
Highlights ► Overall pattern of a decrease in Mg/Ca with increasing test size. ► Environmental rather than calcification rate control main factor for Mg/Ca signal. ► Mg/Ca should be carried out on test size fractions optimised for each species. ► No influence of dissolution on Mg/Ca during settling through the water column. (ABSTRACT)
Friedrich, O., Schiebel, R., Wilson, P.A., Weldeab, S., Beer, S.J., Cooper, M.J., Fiebig, J., 2012. Influence of test size, water depth, and ecology on Mg/Ca, Sr/Ca, δ18O and δ13C in nine modern species of planktic foraminifers. Earth and Planetary Science Letters 319–320, 133--145.
THE LATE BADENIAN TRANSGRESSION IN WESTERN UKRAINE
Qualitative and quantitative characteristics of the palynological content of the Upper Badenian strata at Kudryntsi (western Ukraine) indicate that this succession was deposited in variable environments. The basal siliciclastic series shows a very low content of palynological organic matter and palynofacies, which indicate a restricted environment and/or unfavourable conditions for the palynomorph preservation. The presence of dinoflagellate cysts (and composition of their assemblages) in the upper part of organodetrital limestones and the overlying rhodoid limestones indicates a typical shelf environment. Taxonomically variable dinoflagellate cyst assemblages from particular samples reflect gradual environmental changes – from environments of slightly increased salinity of seawater (strata overlying the siliciclastic series) to open marine, more remote environments during deposition of the upper part of the section examined. The gradual deepening of the sea and decrease of salinity is supported also by the succession of foraminiferal assemblages, which undergo gradual changes from Elphidium spp. assemblages, through Miliolidae assemblage, Lobatula lobatula assemblage, Neoconorbina spp. assemblage to Cibicidoides assemblage. The Late Badenian foraminiferal assemblage from Kudryntsi contains two species common for the Sarmatian, i.e. Elphidium reginum and Elphidium koberi, the latter species known so far from the Sarmatian.
Gedl, P., Peryt, D., 2011. Dinoflagellate cyst, palynofacies and foraminiferal records of environmental changes related to the Late Badenian (Middle Miocene) transgression at Kudryntsi (western Ukraine). ASGP 81 (3), 331--349.
CORRELATION OF THE MIDDLE MIOCENE IN SE POLAND AND WESTERN UKRAINE
The aim of this study is to compare the assemblages of foraminifera and calcareous nannoplankton from the Middle Miocene sediments from SE Poland and western Ukraine. Detailed investigations revealed a high degree of similarity of foraminiferal assemblages of the Pecten/Spirialis beds of Poland and the Kosiv Formation of Ukraine. Assemblages from both areas are characterized by numerous arenaceous species of foraminifera (Hyperammina granulosa, Ammodiscus miocenicus, Haplophragmoides indentatus, H. laminatus), radiolarians, pteropods and index planktic species Velapertina indigena. High degrees of similarity also display assemblages from the Krakowiec beds (Poland) and the Dashava Formation (Ukraine). ...... The calcareous nannoplankton assemblages contain almost identical species. The deposits lying above the evaporites (which belong to the NN6 zone) are included into the NN6, undivided NN6-NN7, and NN7 zones. The gradual impoverishment of the species of the upper part of NN6 and the lower part of NN7 zones is observed. The assemblages of the Krakowiec beds and the upper part of the Kosiv and Dashava formations are of low species diversity and are mainly restricted to a few species with high abundance. The assemblage is composed of placoliths (Coccolithus and Reticulofenestra species), high number of the reworked nannofossils and damaged elements. (ABSTRACT)
Garecka, M, Olszewska, B., 2011. Correlation of the Middle Miocene deposits in SE Poland and western Ukraine based on foraminifera and calcareous nannoplankton. ASGP 81 (3), 309--330.
POTENTIAL REDOX PROXIES AND THE IMPACT OF CLEANING PROTOCOLS
In this study we present an initial dataset of Mn/Ca and Fe/Ca ratios in tests of benthic foraminifera from the Peruvian oxygen minimum zone (OMZ) determined with SIMS. These results are a contribution to a better understanding of the proxy potential of these elemental ratios for ambient redox conditions. Foraminiferal tests are often contaminated by diagenetic coatings, like Mn rich carbonate- or Fe and Mn rich (oxyhydr)oxide coatings. Thus, it is substantial to assure that the cleaning protocols are efficient or that spots chosen for microanalyses are free of contaminants. Prior to the determination of the element/Ca ratios, the distributions of several elements (Ca, Mn, Fe, Mg, Ba, Al, Si, P and S) in tests of the shallow infaunal species Uvigerina peregrina and Bolivina spissa were mapped with an electron microprobe (EMP). To visualize the effects of cleaning protocols uncleaned and cleaned specimens were compared. The cleaning protocol included an oxidative cleaning step. ...... Summarized Mn/Ca and Fe/Ca ratios are potential proxies for redox conditions, if cleaning protocols are carefully applied. The data presented here may be rated as base for the still pending detailed calibration. (ABSTRACT)
Glock, N., Eisenhauer, A., Liebetrau, V., Wiedenbeck, M., Hensen, C., Nehrke, G., 2012. EMP and SIMS studies on Mn/Ca and Fe/Ca systematics in benthic foraminifera from the Peruvian OMZ: a contribution to the identification of potential redox proxies and the impact of cleaning protocols. Biogeosciences 9, 341--359.
EXTENSIVE SEA-ICE FORMATION AND LOW-δ13C BRINE REJECTION DURING LGM
...... there are very few data available to calculate a δ13Cas of modern bottom water dissolved inorganic carbon (DIC) δ13C, and to document how this signal is recorded in benthic foraminiferal δ13C. Here I show that today bottom water in the Atlantic sector of the Southern Ocean is 13C enriched with δ13CDIC values between 0.4 and 1.0‰ and δ13Cas values > 0.4‰, and that this signal is recorded in live and dead epibenthic δ13C. This is in contrast to a uniform modern Antarctic circumpolar δ13CDIC of rather 0.4‰, which hitherto is used as modern framework to compare to low LGM δ13CDIC of southern sourced bottom-water and glacial inter basin differences. I conclude that a potential reduction of the strong Recent thermodynamic imprint during bottom-water generation in glacial times could explain depleted circum Antarctic 13CDIC without associated CO2 enrichment and anoxia in Antarctic bottom waters. The present synoptic compilation of δ13CDIC and live benthic foraminifera δ13C is in support of hypotheses that explain low LGM δ13C by a depletion of southern end-member 13CDIC due to extensive sea-ice formation with low δ13Cas-brine rejection and diminished air–sea gas exchange. (ABSTRACT)
Mackensen, A. , 2012. Strong thermodynamic imprint on Recent bottom-water and epibenthic δ13C in the Weddell Sea revealed: Implications for glacial Southern Ocean ventilation. Earth and Planetary Science Letters 317–318, 20--26.
FORAMINIFERA AS INDICATORS OF MARINE POLLUTANT CONTAMINATION
Analyses of living foraminiferal and environmental parameters near an outfall at Mar Grosso Beach (Laguna, SC, Brazil) demonstrate its usefulness as indicators of domestic sewage pollution. The low species diversity may be due to sand accumulation in the central part. Higher diversity was noted closer to the mouth of Laguna estuarine system where reduced salinity and higher temperatures indicate freshwater influence, suggesting a relationship between increased diversity and greater availability of terrestrial food. On the basis of foraminiferal diversity and average coliform count the higher values are closer to the mouth of the estuarine system and under the influence of the outfall. Due to the effect of local hydrodynamics, the particulate organic waste derived from the outfall does not settle down locally, and thus, do not accumulate nearby. Our hypothesis is that the fine material derived from the outfall is accumulating on the southwestern and northwestern parts of the beach. (ABSTRACT)
Eichler, P.P.B., Eichler, B.B., Sen Gupta, B., Rodrigues, A.R., 2012. Foraminifera as indicators of marine pollutant contamination on the inner continental shelf of southern Brazil. Marine pollution Bulletin 64 (1), 22--30.
CHARACTERIZATION OF THE LATEST DANIAN EVENT IN EGYPT
The Latest Danian Event (LDE) has been recognized on the southern Tethyan margin (Egypt; Tunisia), and in the Atlantic (Zumaia, Spain) and Pacific Oceans (ODP Site 1209). Based on a supraregional carbon isotope excursion, and a negative shift in oxygen isotopes in the Pacific it has been suggested that the LDE is an early Paleogene transient warming event. So far the environmental effects of the LDE have been observed in few sections and details on its impact and duration are scarce. We present a quantitative study of benthic foraminiferal assemblages retrieved from five sections along a depth transect on the Paleocene southern Tethyan shelf (Nile Basin, Egypt) to assess paleoenvironmental change during the LDE. ......
Highlights ► Five Paleocene sections in Egypt represent a depth transect on the Tethyan shelf. ► Benthic foraminifera reflect paleoenvironmental change during the Latest Danian Event (LDE). ► The LDE is associated with shelf dysoxia during rapid transgression. ► The duration of the LDE exceeds other proposed Paleocene hyperthermals. (ABSTRACT)
Sprong, J., Kouwenhoven, T.J., Bornemann, A., Schulte, P., Stassen, P., Steurbaut, E., Youssef, M., Speijer, R.P., in press. Characterization of the Latest Danian Event by means of benthic foraminiferal assemblages along a depth transect at the southern Tethyan margin (Nile Basin, Egypt). Marine Micropaleontology, doi:10.1016/j.marmicro.2012.01.001
CLIMATIC FORCING OF THE DEEP-SEA ECOSYSTEM IN THE PACIFIC OCEAN
There is growing evidence that changes in deep-sea benthic ecosystems are modulated by climate changes, but most evidence to date comes from the North Atlantic Ocean. Here we analyze new ostracod and published foraminiferal records for the last 250,000 years on Shatsky Rise in the North Pacific Ocean. Using linear models, we evaluate statistically the ability of environmental drivers (temperature, productivity, and seasonality of productivity) to predict changes in faunal diversity, abundance, and composition. These microfossil data show glacial-interglacial shifts in overall abundances and species diversities that are low during glacial intervals and high during interglacials. These patterns replicate those previously documented in the North Atlantic Ocean, suggesting that the climatic forcing of the deep-sea ecosystem is widespread, and possibly global in nature. However, these results also reveal differences with prior studies that probably reflect the isolated nature of Shatsky Rise as a remote oceanic plateau. Ostracod assemblages on Shatsky Rise are highly endemic but of low diversity, consistent with the limited dispersal potential of these animals. Benthic foraminifera, by contrast, have much greater dispersal ability and their assemblages at Shatsky Rise show diversities typical for deep-sea faunas in other regions. ...... (ABSTRACT)
Yasuhara, M., Hunt, G., Cronin, T.M., Hokanishi, N., Kawahata, H., Tsujimoto, A., Ishitake, M., 2012. Climatic forcing of Quaternary deep-sea benthic communities in the North Pacific Ocean. Paleobiology 38 (1), 162--179.
ASSEMBLAGES IN THE CURRENT DOMINATED STRAIT OF BONIFACIO
This study explores relationships between benthic foraminiferal assemblages and environmental factors in the Strait of Bonifacio, which separates the islands of Corsica and Sardinia, west of Italy Peninsula.
Benthic foraminifera were identified in 31 samples collected during an oceanographic cruise (“Bocche 2003” – P.I.C Interreg III Project) that provided new geomorphologic and sedimentologic data on the western continental shelf of the strait. Biotic parameters (species diversity, density, Fisher α index, Shannon-Weaver index, and Dominance) were calculated and multivariate analyses (Cluster Analysis, Principal Component Analysis, and Canonical Correspondence Analysis) were performed to quantify foraminiferal assemblages in the context of environmental parameters (depth, current velocities, sediment texture, and organic matter). ...... These results indicate that benthic foraminifera assemblages can be useful as hydrodynamic energy proxy for a valuable characterization of specific environments. (ABSTRACT)
Bousi, C., du Châtelet, E.A., Cherchi, A., 2012. Benthic foraminiferal assemblages in the current-dominated strait of Bonifacio (Mediterranean Sea). The Journal of Foraminiferal Research 42 (1), 39--55.
DISTRIBUTION OF LIVING FORAMINIFERA ON THE GULF OF CADIZ CONTINENTAL SHELF
Living (stained) benthic foraminiferal faunas were analyzed in 51 surficial sediment samples taken from the northern Gulf of Cadiz continental shelf between the mouths of the Guadiana and Guadalquivir rivers. The distribution and abundance of 26 species with relative abundance >5% were related to water depth, sediment type, river discharge, water temperature, salinity, turbidity, and primary productivity. Hierarchical classification using R- and Q-mode cluster analyses, and individual distributions, allowed these taxa to be categorized into four general groups. ...... (ABSTRACT)
Mendes, I., Dias, J.A., Schönfeld, J., Ferreira, Ó., 2012. Distribution of living benthic foraminifera on the northern Gulf of Cadiz continental shelf. The Journal of Foraminiferal Research 42 (1), 18--38.
4000 YEARS OF HABITAT CHANGE IN FLORIDA BAY
Analyses of 203 samples of benthic foraminifera in six cores from four sites in Florida Bay indicate habitat change over the last ~4000 years. Sample ages were determined for the last ~120 years with 210Pb, and for up to ~4000 years at two sites with 14C. The largest habitat changes upcore were identified with stratigraphically constrained cluster analysis (CONISS), which evaluates the similarity of vertically adjacent samples. Paleoenvironmental interpretations of habitat changes were mostly based on varying proportions of two defined associations of environmental indicator taxa and changes in diversity. The timing of the interpreted environmental changes was compared to known natural and anthropogenic events to examine their correspondence and possible relationship. ...... (ABSTRACT)
Cheng, J., Collins, L.S., Holmes, C., 2012. Four thousand years of habitat change in Florida Bay, as indicated by benthic foraminifera. The Journal of Foraminiferal Research 42 (1), 3--17.
BENTHIC FORAMINIFERAL BIOGEOGRAPHY
Benthic foraminifera, shell-bearing protists, are familiar from geological studies. Although many species are well known, undescribed single-chambered forms are common in the deep sea. Coastal and sublittoral species often have restricted distributions, but wide ranges are more frequent among deep-water species, particularly at abyssal depths. This probably reflects the transport of tiny propagules by currents across ocean basins that present few insurmountable barriers to dispersal, combined with slow rates of evolution. Undersampling of the vast deep-sea habitat, however, makes it very difficult to establish the ranges of less common foraminiferal species, and endemism may be more prevalent than currently realized. On continental slopes, some species have restricted distributions, but wide-ranging bathyal species that exhibit considerable morphological variation are more common. This may be linked to the greater heterogeneity of continental slopes compared with oceans basins. Improved knowledge of deep-sea foraminiferal biogeography requires sound morphology-based taxonomy combined with molecular genetic studies.
Gooday, A.J, Jorissen, F.J., 2012. Benthic Foraminiferal Biogeography: Controls on Global Distribution Patterns in Deep-Water Settings. Annual Review of Marine Science 4 (1), 237--262.
FORAM-NANNO INTEGRATED BIOSTRATIGRAPHY OF THE CTB IN THE POLISH CARPATHIANS
The Rybie section (Subsilesian Nappe, Polish Carpathians) comprises hemipelagic and pelagic sediments of the Cenomanian/Turonian boundary (CTB) interval. In general, positioning of the CTB in such sediments is problematic owing to the absence or scarcity of index ammonites or inoceramids, but an integrated stratigraphy of nannofossils, foraminifera and microfacies allowed determination of the CTB within a narrow interval. The standard nannofossil UC zones have been used, and the standard planktonic foraminiferal Thalmanninella reicheli Zone combined with a new local zonation, which includes the Parathalmanninella micheli, Heterohelix and Marginotruncana zones is proposed. A few bio-events related to the CTB were identified, including the Heterohelix shift, the radiolaria domination, the roveacrinid abundance event, the planktonic foraminifera turnover, the deep-water agglutinated foraminifera extinction and the filament event. The CTB interval lies in the lower part of the nannofossil UC5c-6 Zone, and in the middle of the planktonic foraminiferal Heterohelix Zone and of the benthonic foraminiferal Bulbobaculites problematicus Zone. The boundary interval is also above the deep-water agglutinated foraminifera extinction event and below the filament event. The CTB lies between a package of black shales (an equivalent of the Bonarelli Level) and a level of ferro-manganese deposits. (ABSTRACT)
Kędzierski, M., Machaniec, E., Rodríguez-Tavar, F., Uchman, F., in press. Bio-events, foraminiferal and nannofossil biostratigraphy of the Cenomanian/Turonian boundary interval in the Subsilesian Nappe, Rybie section, Polish Carpathians. Cretaceous Research, doi: 10.1016/j.cretres.2011.12.010
END-CRETACEOUS MARINE MASS EXTINCION NOT CAUSED BY PRODUCTIVITY COLLAPSE
An asteroid impact at the end of the Cretaceous caused mass extinction, but extinction mechanisms are not well-understood. The collapse of sea surface to sea floor carbon isotope gradients has been interpreted as reflecting a global collapse of primary productivity (Strangelove Ocean) or export productivity (Living Ocean), which caused mass extinction higher in the marine food chain. Phytoplankton-dependent benthic foraminifera on the deep-sea floor, however, did not suffer significant extinction, suggesting that export productivity persisted at a level sufficient to support their populations. We compare benthic foraminiferal records with benthic and bulk stable carbon isotope records from the Pacific, Southeast Atlantic, and Southern Oceans. We conclude that end-Cretaceous decrease in export productivity was moderate, regional, and insufficient to explain marine mass extinction. A transient episode of surface ocean acidification may have been the main cause of extinction of calcifying plankton and ammonites, and recovery of productivity may have been as fast in the oceans as on land. (ABSTRACT)
Alegret, L., Thomas, E., Lohmann, K.C., in press. End-Cretaceous marine mass extinction not caused by productivity collapse. PNAS, doi: 10.1073/pnas.1110601109
SHIFT IN BIOTIC RESPONSE OF ABYSSAL FORAMINIFERA SINCE MIS 7
We investigated the late Quaternary abyssal benthic foraminiferal faunas from the upper 209 cm of sediment core (KODOS PC5101) in order to understand the biotic response of abyssal benthic foraminifera to the glacial-interglacial cycle in the eastern equatorial Pacific Ocean. Three factor assemblages were identified in the benthic foraminiferal faunas of core PC5101: the common deep-sea fauna for which there is some seasonal food supply (Factor 1 assemblage), the fauna that suffer from possible carbonate undersaturation in the deep waters of the Southern Ocean or low food supply (Factor 2 assemblage), and the fauna for which there is seasonal food supply (Factor 3 assemblage). ...... It is suggested that carbonate undersaturation at the sediment-water interface on the seafloor was one of major factors that influenced benthic foraminiferal fauna at the site of our study, particularly from early MIS 5 to MIS 7. However, additional factors also affected benthic foraminifera from MIS 1 to late MIS 5. For example, enhanced periodicity of the food supply from the surface ocean (i.e., seasonality or ENSO variability) might be another factor responsible for the shift in the biotic response of abyssal benthic foraminifera deposited after MIS 5. (ABSTRACT)
Takata, H., Khim, B.-K., Yoo, C.M., Chi, S.B., 2012. Shift in biotic response of abyssal benthic foraminifera since MIS 7 in the eastern equatorial Pacific Ocean. Geoscience Journal 15 (4), 417--422.
ROCK-SOURCE OF MAYA LIME PLASTER FROM THE TEMPLE OF THE INSCRIPTIONS
This paper introduces for the first time the study and description of fossil remains preserved in lime plaster from a Maya site, the Temple of the Inscriptions in Palenque, one of the most outstanding Classic Period cities of the Maya culture in Mesoamerica. Plaster was removed with EDTA carbonate-digestive technique and results based on ultrastructural microanalysis reveals marine fossil remains of shells and calcareous debris correlated with organisms of several taxa including Foraminifera, Gastropod, Bivalvia, and Cnidarian. This fossil material is associated with several Tertiary fossil-bearing strata in the surroundings of Palenque. Additionally, results of WDX testing on white lumps of plaster show a characteristic MgO/CaO ratio consistent with a dolomitic limestone source linked to the Tenejapa geological unit (Paleocene). Plaster of The Temple of the Inscriptions is best described as a dolomitic lime plaster. ...... (ABSTRACT)
Riquelme, F., Alvarado,-Ortega, J., Cuevas-García, M., Ruvalcaba-Sil, L., Linares-López, C., 2012. Calcareous fossil inclusions and rock-source of Maya lime plaster from the Temple of the Inscriptions, Palenque, Mexico. Journal of Archaeological Science 39 (3), 624--639.
NEW METHOD OF ROCK DISINTEGRATION AND FORAMINIFERAL EXTRACTION
An extremely fast, easy, and clean method of rock disintegration and foraminifera extraction from variously lithified porous rocks with the use of liquid nitrogen [LN2] is proposed. This method markedly limits the time of rock disintegration from days to only minutes, is safe for foraminifera, and does not require special chemical labs. In the experiment, the LN2 method was used to decompose rock samples and simultaneously to extract the foraminifera hidden within. The proposed method disintegrates the rocks to a finer fraction than conventional methods such as the Glauber's Salt method, allowing to collect more smaller planktonic and benthic foraminifera, resulting in marked changes in foraminiferal assemblages e.g., the planktonic/benthic ratio [P/B], leading to new conclusions. The comparison between the LN2 and Glauber's Salt [GS] methods and obtained results are provided. (ABSTRACT)
Remin, Z., Dubicka, Z., Kozłowska, A., Kuchta, B., in press. A new method of rock disintegration and foraminiferal extraction with the use of liquid nitrogen [LN2]. Do conventional methods lead to biased paleoecological and paleoenviromental interpretations?. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.12.001
Mg/Ca EVIDENCE FOR SOUTHERN OCEAN COOLING ACROSS THE E-O TRANSITION
Constraining the magnitude of high-latitude temperature change across the Eocene–Oligocene transition (EOT) is essential for quantifying the magnitude of Antarctic ice-sheet expansion and understanding regional climate response to this event. To this end, we constructed high-resolution stable oxygen isotope (δ18O) and magnesium/calcium (Mg/Ca) records from planktic and benthic foraminifera at four Ocean Drilling Program (ODP) sites in the Southern Ocean. ......
► Southern Ocean temperature history across Eocene–Oligocene transition. ► Study interval spanning 35.0 to 32.5 Ma. ► High-resolution foraminiferal Mg/Ca and δ18O records constructed at four study sites. ► 2–3 °C cooling of Southern Ocean surface waters across Eocene–Oligocene transition. ► Moderate deep-water cooling and full-scale Antarctic glaciation interpreted at 34 Ma. (ABSTRACT)
Bohaty, S.M., Zachos, J.C., Delaney, M.L., 2012. Foraminiferal Mg/Ca evidence for Southern Ocean cooling across the Eocene–Oligocene transition. Earth and Planetary Science Letters 317-318, 251--261.
CLIMATE CHANGE AND EUTROPHICATION ON DINOFLAGELLATE-BEARING FORAMINIFER
Elevated sea surface temperatures caused by global climate change and increased nutrient concentrations resulting from land runoff both are stressors for calcifying coral reef organisms. Here, we test the hypothesis that increased temperature leads to bleaching in dinoflagellate-bearing foraminifera similar to corals and that increased nutrients through runoff can exaggerate stress on the holobiont. In an experiment manipulating temperatures alone, we have shown that mortality of Marginopora vertebralis increased with temperatures. ...... In a flow-though experiment manipulating both temperature (three levels, 26, 29 and 31°C) and nitrate concentrations (3 levels, ~0.5, 1.0 and 1.4 μmol l−1 NO3−), elevated temperature had a significant negative effect on most parameters measured. ...... We conclude that these foraminifera bleach in a similar fashion to corals and that global sea surface temperature change and nitrate increases are stressors for these protists. Furthermore, this provides support for the hypothesis that management of local stressors elevates resilience of coral reefs to global stressors. (ABSTRACT)
Uthicke, S., Vogel, N., Doyle, J., Schmidt, C., Humphrey, C., in press. Interactive effects of climate change and eutrophication on the dinoflagellate-bearing benthic foraminifer Marginopora vertebralis. Coral Reefs, doi: 10.1007/s00338-011-0851-2
PLANKTIC FAUNAS, TEMPERATURE AND SALINITY IN THE GULF STREAM IN THE LAST 30 kyr
Variations in the distribution of planktic foraminiferal faunas, temperature and salinity in the surface water of the Gulf Stream during the last 30,000 years have been reconstructed based on a sediment core from the Blake Ridge, subtropical western Atlantic Ocean. Temperatures and salinities were calculated using planktic foraminiferal transfer functions and previously published oxygen isotope values. Productivity was estimated using the >106 μm size fraction of planktic foraminifera. The reconstructed values show that temperature variations have been small during the investigated period with a total range of only 3 °C. The highest temperatures, about 1.5 °C above the present temperature in the area, occurred during the late Glacial, Heinrich event 1 and the mid Holocene time periods. The lowest temperatures, about 1.5 °C below the present temperatures, occurred during the Bølling interstadial. The early Holocene period was relatively cool. The low temperatures during the Bølling interstadial and during the early Holocene are in contrast to the northeastern Atlantic, where the Bølling interstadial was the warmest period of the deglaciation, and the early Holocene the warmest during the Holocene. We attribute the lower temperatures during the Bølling and early Holocene periods to colder meltwater from the Laurentide Ice Sheet flowing into the Gulf of Mexico through the Mississippi River system and carried to the Blake Ridge via the Gulf Stream. (ABSTRACT)
Rasmussen, T.L., Thomsen, E., in press. Changes in planktic foraminiferal faunas, temperature and salinity in the Gulf Stream during the last 30,000 years: influence of meltwater via the Mississippi River. Quaternary Science Reviews, doi:10.1016/j.quascirev.2011.11.019
EVOLUTION OF MIDDLE TO LATE CRETACEOUS OCEANS
A new 55 m.y. global compilation of benthic foraminifera δ13C and δ18O for the middle to Late Cretaceous shows that there was widespread formation of bottom waters with temperatures >20 °C during the Cretaceous greenhouse world. These bottom waters filled the silled North Atlantic and probably originated as thermocline or intermediate waters in the tropical oceans. Carbon burial during the Cretaceous oceanic anoxic events produced a positive δ13C shift in global carbon reservoirs, but this is not particularly large, especially by comparison with the remarkable Late Paleocene carbon maximum. The interbasin δ13C gradient was unusually large during the Cretaceous hot greenhouse, probably because the North Atlantic sills prevented the free exchange of waters in the deep basin. The hot greenhouse ended when the Equatorial Atlantic Gateway opened sufficiently to flood the deep North Atlantic with relatively cool polar waters formed in the Southern Ocean. (ABSTRACT)
Friedrich, O., Norris, R.D., Erbacher, J., in press. Evolution of middle to Late Cretaceous oceans—A 55 m.y. record of Earth's temperature and carbon cycle. Geology, doi: 10.1130/G32701.1
HOLOCENE PALEOENVIRONMENTAL CHANGES ON THE NE AND SW BLACK SEA SHELVES
Four paleoceanographic events are distinguished during the Holocene based on changes in macro- and microfossil assemblages studied from three sediment cores (Ak 521, 522, 2571) from the outer northeast shelf and from core MAR02-45 situated on the southwest shelf of the Black Sea, west to the Bosphorus. The lithology and fossils were previously studied from cores Ak 521 and Ak 522 and MAR02-45. However, high resolution ostracod analyses from the AMS-14C dated core, Ak 2571, allowed for a revision of the taxonomy and paleoecological interpretation of this microfaunal group on the NE shelf. Downcore changes in the relative abundance of the polyhaline ostracods are found to be contemporaneous in all three cores from the NE shelf. As a result, centennial-millennial scale fluctuations of the bottom-water salinity are resolved in the area. A broader scale examination of paleoenvironmental changes between the NE and SW shelves is also made and the surface to bottom salinity gradient is discussed. An uncalibrated radiocarbon based chronology is used throughout this paper to facilitate comparison with the regional chronostratigraphy of marine transgression and regressions in the Black Sea. The calibrated ages corrected for the changes in reservoir age through the Holocene are also provided. ...... (ABSTRACT)
Ivanova, E.V., Murdmaa, I.O., Karpuk, M.S., Schornikov, E.I., Marret, F., Cronin, T.M., Buynevich, I.V., Platonova, E.A., in press. Paleoenvironmental changes on the Northeastern and Southwestern Black Sea shelves during the Holocene. Quaternaty International, doi:10.1016/j.quaint.2011.11.015
OCEANOGRAPHIC CHANGES THROUGH THE LAST MILLENNIUM OFF NORTH ICELAND
Temperature and salinity reconstructions for two 1000-year high-resolution sedimentary records, located at the boundary between Atlantic and Arctic surface waters on the North Icelandic shelf, are based on transfer functions and oxygen isotopes for planktonic and benthic foraminifera. There is a general increase of Arctic Water indicator species at the transition from the Medieval Warm Period into the Little Ice Age (LIA) and a subsequent return of Atlantic Water indicator species towards the end of the LIA and in the 20th century.
The timing of the reconstructed temperature changes, both at the beginning and at the end of the LIA, appears to be slightly different for the different water masses. The earliest temperature change is seen in the bottom and subsurface waters, where a cooling is reconstructed as early as AD 1150–1200 at both locations, whereas previously published diatom-based and alkenone-based sea-surface temperature reconstructions show a change at AD 1300, coinciding with the air temperature shift in the area. Our results show the need of a thorough understanding of the oceanography in the study area, as well as the different living habitat for the biological proxies used for the temperature estimates. (ABSTRACT)
Knudsen, K.L., Kiriksson, J., Bartels-Jónsdóttir, H.B., , in press. Oceanographic changes through the last millennium off North Iceland: Temperature and salinity reconstructions based on foraminifera and stable isotopes. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.11.002
PALAEOECOLOGY AND PALAEOCEANOGRAPHIC UTILITY OF "Dentoglobigerina" venezuelana
...... A number of proxies are under development, but some of the most promising (e.g. palaeoseawater records of Li and Nd isotope change) can only be employed on such large samples of mono-specific foraminifera that application to the deep sea sediment core archive becomes highly problematic. “Dentoglobigerina” venezuelana presents a potentially attractive target for circumventing this problem because it is a typically large (> 355 μm diameter), abundant and cosmopolitan planktic foraminifer that ranges from the early Oligocene to early Pliocene. Yet considerable taxonomic and ecological uncertainties associated with this taxon must first be addressed. Here, we assess the taxonomy, palaeoecology, and ontogeny of “D.” venezuelana using stable isotope (oxygen and carbon) and Mg/Ca data measured in tests of late Oligocene to early Miocene age from Ocean Drilling Program (ODP) Site 925, on Ceara Rise, in the western equatorial Atlantic. ......
Highlights ► A broad taxonomic concept can be applied to “D.” venezuelana for proxy records. ► “D.” venezuelana maintained a lower thermocline depth habitat from 24 to 21 Ma. ► “D.” venezuelana descended through the water column during its life cycle. ► Possible instability of the tropical Atlantic thermocline during the early Miocene. (ABSTRACT)
Stewart, J.A., Wilson, P.A., Edgar, K.M., Anand, P., James, R.H., in press. Geochemical assessment of the palaeoecology, ontogeny, morphotypic variability and palaeoceanographic utility of “Dentoglobigerina” venezuelana. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.11.003
SEA LEVEL RECONSTRUCTION USING PAM AND LDF
We present a quantitative technique to reconstruct sea level from assemblages of salt-marsh foraminifera using partitioning around medoids (PAM) and linear discriminant functions (LDF). The modern distribution of foraminifera was described from 62 surface samples at three salt marshes in southern New Jersey. PAM objectively estimated the number and composition of assemblages present at each site and showed that foraminifera adhered to the concept of elevation-dependent ecological zones, making them appropriate sea-level indicators. ...... Recognition of biozones in sequences of salt-marsh sediment using LDFs provides a probabilistic means to reconstruct sea level. ...... We compared reconstructions from LDFs and a transfer function. The transfer function provides smaller error terms and can reconstruct smaller RSL changes, but LDFs are well suited to RSL reconstructions focused on larger changes and using varied assemblages. Agreement between these techniques suggests that the approach we describe can be used as an independent means to reconstruct sea level or, importantly, to check the ecological plausibility of results from other techniques. (ABSTRACT)
Kemp, A.C., Horton, B.P., Vann, D.R., Engelhart, S.E., Grand Pre, C.A., Vane, C.H., Nikitina, D., Anisfeld, S.E., in press. Quantitative vertical zonation of salt-marsh foraminifera for reconstructing former sea level; an example from New Jersey, USA. Quaternary Science Reviews, doi:10.1016/j.quascirev.2011.09.014
DIVERSITY ASSOCIATED WITH COLD-WATER CORAL CARBONATE MOUNDS AND OPEN SLOPE
Cold-water coral (CWC) ecosystems are hotspots of macro- and microfaunal biodiversity and provide refuge for a wide variety of deep-sea species. We investigated how the abundance and biodiversity of ‘live’ (Rose Bengal stained) foraminifera varies with, and is related to, the occurrence of CWC on the Rockall Bank (NE Atlantic). Qualitative and quantitative analyses were performed on 21 replicate samples from 8 deep-sea stations, including 4 stations on CWC-covered carbonate mounds at depths of 567-657 m, and 4 stations on the adjacent slope at depths of 469-1958 m where CWC were absent. This sampling strategy enabled us to demonstrate that sediments surrounding the living CWC were characterised by higher foraminiferal abundance and biodiversity than open-slope sediments from the same area. A total of 163 foraminiferal species was identified. ...... We suggest that CWC create a heterogeneous 3-dimensional substrate offering microhabitats to a diverse benthic foraminiferal community. (ABSTRACT)
Morigi, C., Sabbatini, A., Vitale, G., Pancotti, I., Gooday, A.J., Duineveld, G.C.A., De Stigter, H.C., Danovaro, R., Negri, A., in press. Foraminiferal biodiversity associated with cold-water coral carbonate mounds and open slope of SE Rockall Bank (Irish continental margin - NE Atlantic). DeepSea Research I, doi:10.1016/j.dsr.2011.10.004
HISTORY OF THE SUBTROPICAL FRONT AROUND NEW ZEALAND OVER THE LAST 1 myr.
Planktic foraminiferal assemblages in a composite section from two cores (MD06-2989/2986) off the west coast of New Zealand's South Island (42–43.5ºS) provide a 1 myr (MIS 31–1) sea-surface temperature (SST) record (~ 3-4 kyr resolution) in the Tasman Sea. A significant overall faunal change occurred near the end of the mid-Pleistocene Climate Transition (MPT) at ~ 600 ka (MIS 15). Mean annual SSTs were estimated using the Artificial Neural Network (ANN) method. Glacial-interglacial (G-I) cycles in the MPT had ~ 9 °C SST range, whereas in the post-MPT SST range was ~ 6-7 °C. The SST and faunal changes imply that the Subtropical Front (STF) migrated ~ 6˚ in latitude to lie just north of the sites in MPT glacials (MIS 28–16), but only migrated 3-5˚ north in post-MPT glacials. These G-I latitudinal migrations of the STF west of New Zealand contrast with the situation east of New Zealand, where migrations of both the STF and Subantarctic Front were prevented by the Chatham Rise and Campbell Plateau. Subtropical Water is inferred to have only flowed around the south of New Zealand (as it does today) during MIS 11 and the Late Pleistocene-Holocene (MIS 5–1). (ABSTRACT)
Hayward, B.W., Sabaa, A.T., Kolodziej, A., Crundwell, M.P., Steph, S., Scott, G.H., Neil, H.L., Bostock, H.C., Carter, L., Grenfell, H.R., in press. Planktic foraminifera-based sea-surface temperature record in the Tasman Sea and history of the Subtropical Front around New Zealand, over the last one million years. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.10.003
ECOLOGICAL CONTROLS ON THE SHELL GEOCHEMISTRY OF G. ruber
We evaluate the relationship between foraminiferal test size and shell geochemistry (δ13 C, δ18O, and Mg/Ca) for two of the most commonly used planktonic foraminifers for paleoceanographic reconstruction in the subtropical Atlantic Ocean: the pink and white varieties of Globigerinoides ruber. Geochemical analyses were performed on foraminifera from modern core-top samples of high-accumulation rate basins in the northern Gulf of Mexico. ...... Based on this comparison we conclude that pink G. ruber is calcifying in warmer waters than co-occuring white G. ruber, suggesting differences in the relative seasonal distribution and depth habitat of the two varieties.
Highlights ► We evaluate the relationship between test size and shell geochemistry in Globigerinoides ruber. ► Mg/Ca increases, and δ18O becomes more depleted as G. ruber test size increases. ► Data suggest that test size increases with increasing calcification temperature. ► Differences in the geochemistry of pink and white G. ruber suggest distinct depth/seasonal distributions. (ABSTRACT)
Richey, J.N., Poore, R.Z., Flower, B.P., Hollander, D.J., in press. Ecological controls on the shell geochemistry of pink and white Globigerinoides ruber in the northern Gulf of Mexico: Implications for paleoceanographic reconstruction. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.10.002
SHEBI AMONG FORAMINIFERAL SEDIMENT ASSEMBLAGES ON REEFS
Sixteen nearshore (≤ 1 m water depth) sediment samples, termed Sample Set 1, were collected from the eastern and south-western coasts of the South East Peninsula (SEP) of St. Kitts. Twelve samples termed Sample Set 2 were taken from nearby fringing (6 – 17 m) and offshore (~ 18 – 25 m) reefs. The sample sets were analysed separately using SHE Analysis for Biozone Identification (SHEBI), α and β diversities and complementarity. SHEBI is a statistical technique that determines abundance biozones (ABs) using the entire vector of species abundances in samples, species richness S, the information function H, and the equitability index E. Alpha diversity expresses the diversity within an AB, while β diversity quantifies diversity changes between adjacent ABs. Complementarity assesses the permeability of AB boundaries. ......
Highlights ► SHEBI discerns ABs among reefal foraminifera around St. Kitts ► The shore zone (< 1 m depth) comprises ABs arrayed along shore, dominated by Discorbis rosea ► Deeper areas contained ABs arrayed by depth ► Foraminifera indicate that most sediment transport is from fringing reefs shorewards ► Little sediment > 65 microns is transported from the shore to the reefs
Wilson, B., Orchard, K., Phillip, J., in press. SHE Analysis for Biozone Identification among Foraminiferal Sediment Assemblages on Reefs and in Associated Sediment around St. Kitts, Eastern Caribbean Sea, and its Environmental Significance. Marine Micropaleontology, doi:10.1016/j.marmicro.2011.10.001
ANOXIA: EVIDENCE FOR EUKARYOTE SURVIVAL AND PALEONTOLOGICAL STRATEGIES
ANOXIA defines the lack of free molecular oxygen in an environment. In the presence of organic matter, anaerobic prokaryotes produce compounds such as free radicals, hydrogen sulfide, or methane that are typically toxic to aerobes. The concomitance of suppressed respiration and presence of toxic substances suggests these habitats are inhospitable to Eukaryota. Ecologists sometimes term such environments 'Death Zones'. This book presents, however, a collection of remarkable adaptations to anoxia, observed in Eukaryotes such as protists, animals, plants and fungi. Case studies provide evidence for controlled beneficial use of anoxia by, for example, modification of free radicals, use of alternative electron donors for anaerobic metabolic pathways, and employment of anaerobic symbionts. The complex, interwoven existence of oxic and anoxic conditions in space and time is also highlighted as is the idea that eukaryotic inhabitation of anoxic habitats was established early in Earth history. (from Amazon.co.uk)
Altenbach, A.V., Bernhard, J.M., Seckbach, J. (eds), 2012. Anoxia: Evidence for Eukaryote Survival and Paleontological Strategies. Cellular Origin, Life in Extreme Habitats and Astrobiology 21, 648 pp.
ECOLOGICAL REPLACEMENT OF FORAMINIFERA DURING A MAXIMUM FLOODING EVENT
Data from agglutinated benthic foraminiferal assemblages and geochemical proxies make it possible to characterise different order sea-level dynamics —from a geological scale third-order transgressive-regressive cycle to a minor-scale, ecological range, maximum flooding-initial regressive phase— in part of the Valanginian from Spitsbergen. ......
Highlights ► Benthic foraminifera and geochemical proxies characterise sea-level changes. ► Trophic resources and redox conditions controlled the foraminiferal assemblages. ► Transition from maximum flooding to initial regressive phase present ecological replacement. ► Dominant morphogroups are distributed in distinct microhabitats as a result of competition.
Reolid, M., Rodríguez-Tovar, F., Nagy, J., in press. Ecological replacement of Valanginian agglutinated foraminifera during a maximum flooding event in the Boreal realm (Spitsbergen). Cretaceous Research, doi:10.1016/j.cretres.2011.10.003