نتایج جستجو برای: planktonic foraminifera
تعداد نتایج: 9925 فیلتر نتایج به سال:
abtalkh formation is a part of late cretaceous sedimentary unit in the kopet- dagh basin, ne iran. this study deals with the study of this formation in the eastern parts of the basin in padeha village. it thickness is about 991m, and lithologically consists of grey, greyish to blue shale and marl. the lower contact with abderaz formation is conformable and transitional, but the upper boundary w...
planktonic foraminifera are useful in determining the relative age of the upper cretaceous strata. based on distribution of planktonic foraminifera in kuh-e siah section (212 m thickness), eight biozones have been recognized including dicarinella concavata interval zone (earliest santonian), dicarinella asymetrica total range zone (santonian to earliest campanian), globotruncanita elevata parti...
Major negative oxygen isotopic anomalies in planktonic foraminifera are associated with deep-sea anoxic mud layers (sapropels) deposited 9000 and 80,000 years ago in the eastern Mediterranean. The isotopic depletion in surface-dwelling foraminifera is significantly greater than in mesopelagic foraminifera. This difference in isotopic response suggests that surface-water salinities were drastica...
[1] We studied the seasonality of planktonic foraminifera during the Last Glacial Maximum using a foraminifera model coupled to an ecosystem model. The model suggests that the timing of the maximum seasonal production of planktonic foraminifera during the Last Glacial Maximum occurred at a different time of the year from present day. The assumption of ‘‘stable’’ seasonality through time, one of...
the investigated section cropping out in kuh-e-banesh, zagros basin (southern iran) is represented by limestone, cherty beds and marllevels bearing abundant planktonic foraminifers, radiolarian microfaunas, and ammonite imprints. for the first time, well to moderatelypreserved forms of planktonic foraminifera have been extracted from black shale and marls levels. extracted biota was studied wit...
an abrupt global warming event has been recorded in many parts of the world in sediments of latest maastrichtian age between 65.45-65.10 ma. this warm event was documented here at a section near ziyarat-kola in central alborz based on analysis of planktonic foraminifera. an unusual abundance of normally large-size species such as globotruncana arca, globigerinelloides subcarinatus, pseudoguembe...
Referee3: Review of the manuscript "Reconciling single chamber Mg/Ca with whole test d18O in surface to deep dwelling planktonic foraminifera from the Mozambique Channel“ by J. Steinhardt, C. Cleroux, L. de Nooijer, G.-J. Brummer, R. Zahn, G. Ganssen, and G.-J. Reichart. This manuscript presents a large data set of single specimen stable isotopes and single chamber Mg/Ca on four species of plan...
Cifelli, Richard. Textural Observations on Some Living Species of Planktonic Foraminifera. Smithsonian Contributions to Paleobiology, n u m b e r 45, 45 pages, 15 plates, 1982.—Wall textures of 11 species of spinose and quasi-spinose planktonic foraminifera collected in plankton tows from the Nor th and Equator ia l Atlantic have been studied with the scanning electron microscope. Il lustration...
in order to study of biostratigraphy and age dating of kazhdumi formation, based on planktonic foraminifera and correlation of identified biozones with global standard biozones, this formation at tang-e-maghar have been studied. in this study 73 samples of kazhdumi formation, with 270 meter thickness, have been collected. the main lithological units at the studied section consist of the black b...
Oligotrophic regions represent up to 75% of Earth’s open-ocean environments. They are thus areas of major importance in understanding the plankton community dynamics and biogeochemical fluxes. Here we present fluxes of total planktonic foraminifera and 11 planktonic foraminifer species measured at the Oceanic Flux Program (OFP) time series site in the oligotrophic Sargasso Sea, subtropical west...
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