Geochemical tools and paleoclimate clues : multi-molecular and isotropic investigations of tropical marine sediments and alpine ice

South American climate has undergone dramatic changes since the last glacial period, as evidenced from Cariaco Basin (Venezuelan coast) and Peru Margin marine sediment biomarker records. Compounds derived from vascular plant leaf waxes and delivered to the marine sedimentary environment, including long-chain (C24-C32) n-alkanoic acids, were used as proxies for terrestrial vegetation type, aridity, and atmospheric circulation. Marine biomarkers, such as sterols and phytol, were used to reconstruct productivity in the Peru Margin upwelling zone, where sedimentary conditions are not conducive to the preservation of foraminifera. Through the use of organic molecular isotopic techniques and multi-molecular stratigraphy, a great deal can be learned about communities of marine organisms and terrestrial plants that existed in the past and the environments in which they lived. Vascular plant leaf wax carbon and hydrogen isotopic records were generated from n-alkanoic acids preserved in Cariaco Basin marine sediments. These records were compared to previously established pollen and climate records and were found to parallel local millennial-scale climate changes between the late Glacial and Preboreal periods, which were characterized by migrations of the inter-tropical convergence zone.

Department dc:contributor.department

Joint Program in Oceanography/Applied Ocean Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Makou, Matthew C

Advisor dc:contributor.advisor

• Deila W. Oppo.

• /Woods Hole Oceanographic Institution. Joint Program in Oceanography/Applied Ocean Science and Engineering.
• Earth, Atmospheric, and Planetary Sciences.
• Woods Hole Oceanographic Institution.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/34568
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/34568

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34568