Open AccessEquatorial Pacific productivity and dust flux during the mid‐Pleistocene climate transition
Author(s) -
Winckler Gisela,
Anderson Robert F.,
Schlosser Peter
Publication year - 2005
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/2005pa001177
Subject(s) - terrigenous sediment , oceanography , geology , pleistocene , glacial period , climate change , productivity , ice core , barium , paleoceanography , tephra , paleoclimatology , climatology , environmental science , geochemistry , volcano , sedimentary rock , paleontology , chemistry , inorganic chemistry , economics , macroeconomics
We present a helium isotope record for core TT013‐114PC from the central equatorial Pacific (140°W, 4°N, 4432 m water depth) spanning a period of 1 million years. We focus on the time interval from 560 to 800 kyr, largely coinciding with the mid‐Pleistocene climate transition (MPT) when the dominant period of the Earth's climate variability shifted from 41 kyr to 100 kyr. The terrigenous 4 He concentrations from our study correlate very well with published titanium concentrations in this core strongly supporting the use of terrigenous 4 He as a monitor of continental dust. Normalizing titanium and terrigenous 4 He concentrations to 3 He suggests that the dust supply during the MPT was approximately 30% lower compared to the subsequent period (560–100 kyr). The 3 He‐normalized barium, aluminum and phosphorus concentrations, trace elements with a predominantly biogenic source in these sediments, are relatively constant. This is in contrast to previous studies that reported an apparent rise of titanium‐normalized productivity proxies. Rather than a significant increase in productivity during the MPT, we conclude that the dust flux to the central equatorial Pacific was reduced and that the export productivity was approximately constant during this period of climate reorganization.