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Seminar

[Focus]Arsenic and Mercury cycles at the convergent margin of Philippine Sea Plate, Southwest Japan: Importance of plate tectonics for the toxic elements contamination in the geosphere and hydrosphere

2018-06-29 21

Speaker: Prof. Harue MASUDA, Osaka City University
Time: 15:00 - 16:30, 5th Jul., 2018
Venue:  Lecture Hall 221, ISESS (No. 16, Weijin Campus, Tianjin University)
Abstract
Geochemical proxies preserved in scleractinian corals may provide valuable estimates of the past sea surface temperature (SST) at sub-annual resolution over many centuries. The majority of these records rely on the individual proxy-record (e.g. d18O or Sr/Ca) of coral aragonite, which shows a strong correlation with SST. However, these proxies are also subject to biologic and/or kinetic ‘vital effects’ that complicate their interpretation as SSTs. In this talk, I will present multi-proxy approaches to deconvolve the strong ‘vital effects’ (or ‘biological effect’) that affect each individual proxy, including using simultaneous analysis of multiple element ratios (Mg/Ca, Sr/Ca and Ba/Ca), the development of Mg isotope as a temperature proxy, and using combined oxygen and boron isotopes. These approaches not only can yield improved SST estimates, but also help to constrain the biomineralization process in the coral skeleton.