(Table 1) Oxygen and carbon isotopes for foraminiferal taxa at DSDP Hole 76-540
Cobertura |
LATITUDE: 23.828800 * LONGITUDE: -84.370800 * DATE/TIME START: 1981-01-19T00:00:00 * DATE/TIME END: 1981-01-19T00:00:00 * MINIMUM DEPTH, sediment/rock: 177.86 m * MAXIMUM DEPTH, sediment/rock: 236.14 m |
---|---|
Data(s) |
03/04/1984
|
Resumo |
We analyzed the oxygen and carbon isotopic composition of planktonic and benthic foraminifers picked from 13 late Eocene to late Oligocene samples from DSDP Site 540 (23°49.73'N, 84°22.25'W, 2926 m water depth) from the Gulf of Mexico. An enrichment occurs in 18O of about 0.5 to 0.8 per mil in both benthic foraminifers and surface-dwelling planktonic foraminifers between the latest Eocene and early Oligocene. This early Oligocene maximum is followed by lower 18O values. A 1.2 per mil d13C decrease in both benthic and planktonic foraminiferal data occurs from the late Eocene to the late Oligocene. There is a correspondence of the 13C signal to deep-sea records; however, the amplitude of this change is greater than previously seen in deep-sea cores, possibly as a result of proximity to terrestrial sources of carbon. The covarying isotopic changes in both benthic and planktonic foraminifers suggest global causes, such as ice volume increases and increased terrestrial carbon input to the ocean. However, during the latter part of the record (early-late Oligocene), the increases in the benthic 18O without accompanying increases observed with planktonic foraminifers suggest that changes in only one part of the system occurred; one potential explanation being a decrease in bottom-water temperatures without concomitant changes in the surface waters. The 18O differences between species of planktonic foraminifers and the difference between planktonic and benthic 18O data indicate that diagenesis problems are minimal. These preliminary results are encouraging given that these cores are partially lithified. |
Formato |
text/tab-separated-values, 86 data points |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.809678 doi:10.1594/PANGAEA.809678 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Belanger, PE; Matthews, RK (1984): The foraminiferal isotope record across the Eocene/Oligocene boundary at Deep Sea Drilling Project Site 540. In: Buffler, RT; Schlager, W; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 77, 589-592, doi:10.2973/dsdp.proc.77.124.1984 |
Palavras-Chave | #77-540; Chiloguembelina cubensis, d13C; Chiloguembelina cubensis, d18O; Cibicidoides spp., d13C; Cibicidoides spp., d18O; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; Globigerina ampliapertura, d13C; Globigerina ampliapertura, d18O; Globigerinatheka spp., d13C; Globigerinatheka spp., d18O; Glomar Challenger; Gulf of Mexico; Hantkenina sp., d13C; Hantkenina sp., d18O; Hanzawaia cushmani, d13C; Hanzawaia cushmani, d18O; Leg77; Mass spectrometer VG Micromass 602; ODP sample designation; Oridorsalis spp., d13C; Oridorsalis spp., d18O; Pseudohastigerina sp., d13C; Pseudohastigerina sp., d18O; Sample code/label |
Tipo |
Dataset |