Matell, Nora et al. (2005): Tropical Atlantic coccolith Sr/Ca productivity records from the Paleocene-Eocene Thermal Maximum

Leg/Site/Hole:
ODP 113
ODP 198
ODP 207
ODP 198 1209
ODP 207 1258
ODP 113 690
Identifier:
2006-042582
georefid

Creator:
Matell, Nora
Williams College, Department of Geoscience, Williamstown, MA, United States
author

Theberge, Ashleigh
Woods Hole Oceanographic Institution, United States
author

Stoll, Heather M.
author

Shimuzu, Nobumichi
author

Identification:
Tropical Atlantic coccolith Sr/Ca productivity records from the Paleocene-Eocene Thermal Maximum
2005
In: Anonymous, Geological Society of America, Northeastern Section, 40th annual meeting
Geological Society of America (GSA), Boulder, CO, United States
37
1
76
One hypothesis explaining the rapid recovery of temperature and atmospheric carbon following the PETM involves increased primary marine productivity and subsequent carbon burial in deep ocean sediments. The tropics, which contain the majority of the world's oceanic surface area, are of particular importance in evaluating the geographic extent of this proposed feedback. Previous research is limited to sites in the Antarctic (ODP site 690) and the mid-latitude Pacific (ODP site 1209). Here we present Sr/Ca of coccoliths as a proxy for productivity changes at ODP site 1258 Demerara Rise in the tropical Atlantic. Sr/Ca incorporation in coccoliths has been shown to be positively correlated with productivity. We measured Sr/Ca in bulk samples of two different size sediment fractions (5-8 mu m and 8-12 mu m) via Atomic Absorption Spectroscopy, and in individually picked coccoliths of several genera using Secondary Ion Mass Spectrometry ion probe. This allows us to isolate the productivity responses of specific genera. Sample depths ranged from 176.0 mbsf to 171.75 mbsf, providing data points encompassing the PETM and the surrounding time period. Toweius showed a large decrease in productivity during the PETM, eventually recovering to near pre-PETM levels. In contrast, Coccolithus pelagicus showed an increase in productivity during the event. Bulk data for the 5-8 mu m and 8-12 mu m sediment fractions showed similar trends to Toweius and C. pelagicus, respectively. The presence of additional genera in the bulk samples accounts for minor deviations from the genus specific data. The difference in the productivity response of these two genera is likely due to varied modification of their respective ecological niches produced by the conditions of the PETM. Combined with previous research from OPD sites 690 and 1209, the data indicate that there was no unified coccolithophorid response to the PETM. In the tropics and mid-latitudes, there are examples of both productivity increases and decreases among different genera, whereas in the high latitudes all studied genera appear have increased or constant productivity.
English
Coverage:Geographic coordinates:
North:32.4000
West:-54.4400East: 158.3100
South:-65.0938

Stratigraphy; algae; alkaline earth metals; Atlantic Ocean; biochemistry; calcium; Cenozoic; Coccolithophoraceae; Coccolithus; Coccolithus pelagicus; Demerara Rise; Eocene; Equatorial Atlantic; experimental studies; geochemical indicators; geochemistry; ion probe data; Leg 113; Leg 198; Leg 207; lower Eocene; marine environment; mass spectra; metals; microfossils; North Atlantic; Northwest Atlantic; Ocean Drilling Program; ODP Site 1209; ODP Site 1258; ODP Site 690; Pacific Ocean; Paleocene; Paleocene-Eocene Thermal Maximum; paleoclimatology; paleoecology; Paleogene; paleotemperature; PETM; Plantae; Southern Ocean; spectra; Sr/Ca; strontium; Tertiary; tropical environment; upper Paleocene;

.