Multispecies Record of Benthic Foraminiferal Shell Weight in Santa Barbara Basin: A Deglacial Environmental Record
Abstract
There exists increasing interest in resolving the effect of environmental parameters on foraminiferal test weight. We utilize a high-resolution core, MV0811-15JC (34°36.930' N, 119°12.920' W; 418m water depth; 3-15 ka; sedimentation rate ~100cm/ka) from the Santa Barbara Basin (SBB) to examine a multispecies record of benthic foraminiferal weight and test wall thickness. We compare these findings to records of benthic ecosystem, oxygenation and δ18O change during and since the last deglaciation. Ongoing work in SBB has characterized drastic changes in benthic communities over the past 15 kyr in response to climate and dissolved oxygen concentrations. Records of the average test weight in the >250 μm size fraction of Uvigerina peregrina covary with changes in the benthic community in response to oxygenation events and may represent a record of average maximum growth size. Average test weight, constrained by a narrow size fraction (within < 55 μm difference in mesh size), is sometimes treated alone or with additional size correction as a proxy for test wall thickness. Narrow fraction test weights show significantly less variability in both Uvigerina peregrina and Bolivinia argentea between samples. We further analyze average test wall thickness in these samples, to develop an understanding of controls on shell weight and ongoing work seeks, to identify ideal benthic target species and to best understand shell weight as a proxy for carbonate ion (pH) of seawater.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMPP23F..05D
- Keywords:
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- 0404 BIOGEOSCIENCES / Anoxic and hypoxic environments;
- 1635 GLOBAL CHANGE / Oceans;
- 3030 MARINE GEOLOGY AND GEOPHYSICS / Micropaleontology;
- 4944 PALEOCEANOGRAPHY / Micropaleontology