Peruvian mollusk shells as multi-proxy archives: late Holocene upwelling variation and El Niño-induced biomineralization effects on trace elements

Show simple item record

dc.contributor Aharon, Paul
dc.contributor Hodgins, Greg
dc.contributor Perez-Huerta, Alberto
dc.contributor Weislogel, Amy L.
dc.contributor.advisor Andrus, C. Fred T. Etayo-Cadavid, Miguel Fernando 2017-03-01T14:36:16Z 2017-03-01T14:36:16Z 2010
dc.identifier.other u0015_0000001_0000406
dc.identifier.other EtayoCadavid_alatus_0004D_10433
dc.description Electronic Thesis or Dissertation
dc.description.abstract The purpose of this research is to characterize Peruvian upwelling during the late Holocene (last 2000 years) using molluscan proxies. Peruvian upwelling is a key component of El Niño/Southern Oscillation (ENSO) cycle, an important factor introducing interannual variability to Earth's weather. Thus by studying Peruvian paleoupwelling a better picture of past ENSO conditions can be inferred. High resolution sampling for radiocarbon and stable oxygen isotopes in modern pre-bomb Donax obesulus and Protothaca asperrima shells revealed sub-seasonal variations in Peruvian upwelling. Based on the shells' radiocarbon data a new reservoir effect correction (ΔR) was calculated for the Peruvian coast. ΔR, the radiocarbon age difference between global and local marine reservoirs, is also a qualitative proxy for deep water upwelling. A Trachycardium procerum shell that survived the 1982-1983 El Niño revealed that biomineralization changes induced by this event likely affected trace element incorporation into molluscan aragonite. Detected variations in mollusk biomineralization linked to El Niño suggest the need for coupled structural and chemical analyses in environmental proxy studies. Comparison between modern pre-bomb and archaeological ΔR obtained from D. obesulus shells revealed similar upwelling rates in northern Peru for the 20th and 16th centuries and lower rates for the 6th century. Low upwelling rates in northern Peru in the 6th century are in agreement with reported Mega- El Niño events that contributed to the political decline of Moche society.
dc.format.extent 126 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Geology
dc.subject.other Paleoclimate Science
dc.subject.other Geochemistry
dc.title Peruvian mollusk shells as multi-proxy archives: late Holocene upwelling variation and El Niño-induced biomineralization effects on trace elements
dc.type thesis
dc.type text University of Alabama. Dept. of Geological Sciencess Geology The University of Alabama doctoral Ph.D.

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


My Account