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Perez, ME, Charles CD, Berger WH.  2001.  Late Quaternary productivity fluctuations off Angola: evidence from benthic foraminifers, Site 1079. Proceedings of the Ocean Drilling Program Scientific Results. 175   10.2973/odp.proc.sr.175.213.2001   Abstract

Benthic foraminifer accumulation rates (BFAR) >150 ┬Ám and species composition were used to reconstruct the late Quaternary productivity in the Mid-Angola Basin at Ocean Drilling Program Site 1079. In general, BFAR values indicate higher productivity during glacial periods than during interglacials. Spectral analysis of the BFAR record shows that benthic foraminifers were sensitive to climate forcing at 100- and 23-k.y. periodicities. These results are similar to those observed in nearby regions, as described by the Geo-Bremen group. The benthic foraminiferal fauna is dominated by low oxygen-tolerant infaunal species, with Bolivina pseudopunctata and Bolivina dilatata as the most abundant species. B. pseudopunctata appears to be well correlated with marine organic carbon (Corg), whereas B. dilatata tends to increase when the influx of terrigenous organic matter dominates the environment. Furthermore, the spikiness in the abundance of B. pseudopunctata suggests that this species may be opportunistic and may respond to threshold values in environmental conditions.

Perks, HM, Charles CD, Keeling RF.  2002.  Precessionally forced productivity variations across the equatorial Pacific. Paleoceanography. 17   10.1029/2000pa000603   AbstractWebsite

[1] Measurements of combustion oxygen demand (COD) in two sediment cores provide a record of paleoproductivity driven by surface-ocean dynamics in the equatorial eastern and western Pacific for the past 400,000 years. The COD time series are well correlated with each other over this time span and show pronounced precessionally forced peaks of higher productivity during globally colder periods. The phase of this signal in the two cores is identical, to within chronological uncertainties, suggesting a common insolation forcing mechanism for the upper ocean across the equatorial Pacific. COD is also in phase with the precessionally forced component of global ice volume, as indicated by oxygen isotopes, and with atmospheric methane in the Vostok ice core. These relationships imply that the COD relative paleoproductivity index provides an important diagnostic measure of the mechanisms of tropical ocean dynamics and climate change.