Publication Date:
2023-06-27
Description:
Oxygen isotope analyses of Tertiary and Cretaceous planktic foraminifera indicate that species have been stratified with respect to depth in the water column at least since Albian time. There is a relationship between morphology and depth habitat. Species with globigerine morphology have consistently occupied shallower depths than have species with globorotalid morphology. Biserially arranged species occupied both shallow and deep levels in the water column. On the average, it appears that ancient species with shallow habitats have been more susceptible to dissolution and have been preserved less well than species dwelling in deeper habitats. This relationship is similar to that observed for Recent planktic foraminifera. Comparison of carbon isotope ratios of adult and juvenile forms indicates that either the source of the carbon found in the shell or the carbon isotopic fractionations which occur during calcite secretion change during the development of individual foraminifera. The carbon isotopic ratios do not provide a reliable means for reconstructing the depth habitats of ancient species. Temperature-depth profiles for tropical Tertiary oceans have been reconstructed from the isotopic temperatures of planktic and benthic foraminifera. The vertical thermal structure of Oligocene oceans resembled that of modern oceans most closely. Those of Paleocene and Maastrichtian times differed most from that of modern oceans.
Keywords:
17-167; 32-305; 32-306; 6-47B; 6-48B; 7-62A; Age model; Biozone; BrazosRiver; Calculated from stable oxygen isotopes; Comment; CorsicanaBrinkPit; D-11; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; DW-12; DWBG-118C; DWHG-85; Epoch; Event label; Foraminifera, benthic δ13C; Foraminifera, benthic δ18O; Foraminifera, planktic δ13C; Foraminifera, planktic δ18O; GC; Glomar Challenger; Gravity corer; Horizon; LakeWaxahachiespillway; Latitude of event; Leg17; Leg32; Leg6; Leg7; Longitude of event; LSDH; LSDH-077G; LUSIAD-H; North America, U.S.A.; North Pacific/CONT RISE; North Pacific/PLATEAU; North Pacific/RIDGE; ORDINAL NUMBER; OUTCROP; Outcrop sample; Pacific Ocean; PC; Piston corer; RC05; RC05-12; Robert Conrad; Sample code/label; Species; Temperature, calculated; Temperature, difference; WA-18; δ13C, carbonate; δ18O, carbonate; δ18O, standard deviation
Type:
Dataset
Format:
text/tab-separated-values, 1067 data points
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