Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Journal of the Geological Society

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by HUIZHONG, W. Articles by McCAVE, I. N. Search for Related Content GeoRef GeoRef Citation

Distinguishing climatic and current effects in mid-Pleistocene sediments of Hatton and Gardar Drifts, NE Atlantic

¹ Department of Marine Geology, Tongji University, Sipin Road, Shanghai, China
² Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB23EQ, UK

Samples taken from DSDP sites 552 and 553 on Hatton Drift and site 611 on Gardar Drift in the northeast Atlantic Ocean were examined by analyses of carbonate content, coarse fraction amount and composition, fine fraction size and composition, and oxygen isotope ratios. The age of both sections is the mid-Pleistocene, ranging from the end of the Jaramillo Normal Event to the boundary between the Matuyama and Brunhes epochs (about 0.77–0.96 Ma). Records of this time show a change from a dominance of 23 ka to longer periodicity at about 0.818 Ma. This is marked at site 552, but less so at site 611. The grain size is mainly controlled by coccoliths, foraminifera and ice-rafted material, all of which are related to glacial-interglacial changes. Zones barren of and abundant in coccoliths are sensitive indicators of climatic effect. Carbonate increase lags behind foraminiferal oxygen isotope records of surface warming in several glacial to interglacial transitions at both drifts. Different types of carbonates oozes occur on Hatton and Gardar drifts. Of several possible factors influencing these, bottom current effects seem more significant than others, deduced from size analysis of the fine fraction. Sedimentological results in this study further confirm that sediment drifts in the NE Atlantic have maintainted their basic characteristics at least since the mid-Pleistocene.

This article has been cited by other articles:

				M. D. Iglesias-Rodriguez, P. R. Halloran, R. E. M. Rickaby, I. R. Hall, E. Colmenero-Hidalgo, J. R. Gittins, D. R. H. Green, T. Tyrrell, S. J. Gibbs, P. von Dassow, et al. Phytoplankton Calcification in a High-CO2 World Science, April 18, 2008; 320(5874): 336 - 340. [Abstract] [Full Text] [PDF]