Xiaoli Zhou

Department of Earth Sciences

312 Heroy GL

Email: xzhou18@syr.edu

Xiaoli's CV

PhD Student Earth Sciences
Advisor: Zunli Lu

Research Interests

My interests in paleoclimate include the changes of redox conditions during the Paleocene-Eocene Thermal Maximum (PETM), as well as through the whole Cenozoic Era. PETM is a good analog of current global warming, with an increase of temperature up to 10 °C within 6 kyr. This thermal event was supposed to be induced by the addition of tones of 13C depleted carbon to the atmosphere-ocean system. A series of environmental changes followed the initial of the global warming, including benthic foraminifera extinction event (BEE). Potential causes of this event include increased temperature, enhanced or reduced marine productivity, and lower oxygen levels in the ocean. Although the evidence of global hypoxia/anoxia has not been detected, short hypoxia/anoxia events might have been missed due to the low resolution of redox data. I propose to build a redox record of the PETM by analyzing carbonates and foraminifera from Ocean Drilling Program (ODP) sites, using I/Ca ratio as a redox proxy. Among all the biophilic elements, the redox potential of iodate/iodide is the closest to oxygen/water. Experiments have shown that only iodate iodine will enter the structure of carbonates. As a result, I/Ca ratio has been proved to be a redox proxy of paleoclimate.

Picture of Xi Chen, DOn Siegel and Sunshyne Hummel (R) sampling a well

Although oxygen is important to biota, we know little about the redox history in the past. Previous researchers have designed models to simulate the atmospheric oxygen concentrations for Phanerozoic. However, no geochemical data have been provided to support the modeled result. I aim to build a redox history of Cenozoic by determining I/Ca ratios of carbonates and foraminifera in marine sediments from ODP sites.

Another project I am focusing on is the method development of iodine extraction from organic matter. Although I/Ca ratios in carbonates reflect the changes in redox conditions, variations in total available iodine also affects the amount of iodine exist in carbonates. So it's important to determine the iodine concentration in organic matter before we attribute all the changes of I/Ca ratios to redox variations. Before measuring iodine in organic samples, it’s critical to extract all the iodine contained in the sample to a solution. Commonly, people extract iodine from solids in two ways, i.e., pyrohydrolysis and alkaline extraction. People are able to extract iodine and determine the concentration for present materials. However, no one have examined whether these methods suit for old organic matter or not. I propose to develop an extraction method in high resolution with small sample mass and low detection limit for old geological rock samples by alkaline extraction.


  • EAR 203 Earth System Science, Professor: Gregory Hoke, Spring 2013
  • EAR 111 Climate Change: Past & Present, Professor: Zunli Lu, Fall 2012
  • EAR 203 Earth System Science, Professor: Gregory Hoke, Spring 2012
  • EAR 101 Dynamic Earth, Professor: Robert Moucha, Spring 2012
  • EAR 111 Climate Change: Past & Present, Professor: Zunli Lu, Fall 2011


Zhou, X., Domack, E., Rickaby, R., Wellner, J., Lu, Z., in review (submitted January 2013). Extensive glendonite deposits indicating post phosphorus recycling. Geology.



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