Strengthening of North American dust sources during the late Pliocene (2.7Ma)


Contact
David.Naafs [ at ] awi.de

Abstract

Here we present orbitally-resolved records of terrestrial higher plant leaf wax input to the North Atlantic over the last 3.5 Ma, based on the accumulation of long-chain n-alkanes and n-alkanl-1-ols at IODP Site U1313. These lipids are a major component of dust, even in remote ocean areas, and have a predominantly aeolian origin in distal marine sediments. Our results demonstrate that around 2.7 million years ago (Ma), coinciding with the intensification of the Northern Hemisphere glaciation (NHG), the aeolian input of terrestrial material to the North Atlantic increased drastically. Since then, during every glacial the aeolian input of higher plant material was up to 30 times higher than during interglacials. The close correspondence between aeolian input to the North Atlantic and other dust records indicates a globally uniform response of dust sources to Quaternary climate variability, although the amplitude of variation differs among areas. We argue that the increased aeolian input at Site U1313 during glacials is predominantly related to the episodic appearance of continental ice sheets in North America and the associated strengthening of glaciogenic dust sources. Evolutional spectral analyses of the n-alkane records were therefore used to determine the dominant astronomical forcing in North American ice sheet advances. These results demonstrate that during the early Pleistocene North American ice sheet dynamics responded predominantly to variations in obliquity (41 ka), which argues against previous suggestions of precession-related variations in Northern Hemisphere ice sheets during the early Pleistocene.



Item Type
Article
Authors
Divisions
Programs
Publication Status
Published
Eprint ID
25594
DOI 10.1016/j.epsl.2011.11.026

Cite as
Naafs, B. D. A. , Hefter, J. , Acton, G. , Haug, G. H. , Martínez-Garcia, A. , Pancost, R. and Stein, R. (2012): Strengthening of North American dust sources during the late Pliocene (2.7Ma) , Earth and Planetary Science Letters, 317-31 , pp. 8-19 . doi: 10.1016/j.epsl.2011.11.026


Download
[thumbnail of Naafs_et_al.,_2012.pdf]
Preview
PDF
Naafs_et_al.,_2012.pdf

Download (4MB) | Preview
Cite this document as:

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Citation

Research Platforms
N/A

Campaigns
N/A


Actions
Edit Item Edit Item