19. Late Quaternary Productivity Fluctuations off Angola: Evidence from Benthic Foraminifers, Site 10791

M. Elena Pérez,2 C.D. Charles,2 and W.H. Berger2


Benthic foraminifer accumulation rates (BFAR) >150 µm 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.

1Pérez, M.E., Charles, C.D., and Berger, W.H., 2001. Late Quaternary productivity fluctuations off Angola: evidence from benthic foraminifers, Site 1079. In Wefer, G., Berger, W.H., and Richter, C. (Eds.), Proc. ODP, Sci. Results, 175 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/175_SR/chap_19/chap_19.htm> [Cited YYYY-MM-DD]

2Scripps Institution of Oceanography, University of California, San Diego, La Jolla CA 92903-0244, USA. Correspondence author: meperez@ucsd.edu

Initial receipt: 25 July 2000
Acceptance: 4 June 2001
Web publication: 27 August 2001
Ms 175SR-213