美国罗格斯大学周晓理博士学术报告

地球系统科学论坛第636期：美国罗格斯大学周晓理博士学术报告

应遊雅堂 競馬章军锋教授和地球生物学系邀请，美国罗格斯大学周晓理博士来我校交流访问，并做学术报告。

报 告 人：周晓理 博士

报告题目：Novel proxy view on Cenozoic ocean chemistry and continental weathering

报告时间：2018年12月5日（星期三）下午14:00

报告地点：学海斋（主楼412）

报告简介：Cenozoic climate has transitioned from a warmhouse to an icehouse, manifest as decreasing seawater temperature and atmospheric pCO₂. What caused the changes in temperature and pCO₂, however, has not been fully resolved. Since ocean chemistry is tightly coupled with global carbon cycle on multi-million-year timescale, studies on ocean chemistry can provide potentials to understand long-term changes in carbonate system including pCO₂. Major ion concentrations such as Mg and Ca concentrations in seawater ([Mg]sw and [Ca]sw) presumably have changed over the Cenozoic, but existing proxies yielded inconsistent [Mg]sw and [Ca]sw records. To resolve this problem, here I propose to use Na/Ca in foraminifera as a proxy for [Ca]sw. This proxy is testified by culture experiments and core-top samples. The downcore Na/Ca records of three species of foraminifera are generated from multiple locations in the Atlantic and Pacific Ocean. A generally increasing trend in the Na/Ca records suggests a monotonic decrease in [Ca]sw and increase in (Mg/Ca)sw since Eocene. Such a long-term change in [Ca]sw and (Mg/Ca)sw may be a result of coupled changes in continental weathering and hydrothermal flux. High [Ca]sw suggests low carbonate ion concentration ([CO₃^2-]) in the early Cenozoic, which may help explain the high pCO₂ at that time.

报告人简介：周晓理博士,2011 年本科毕业于中国科学技术大学地球化学专业。之后就读于美国雪城大学（Syracuse University），2016年获博士学位。师从陆尊礼教授，用碳酸钙中的碘钙比研究古海洋中氧气含量的变化，其研究结果以第一作者发表在 Paleoceanography and Paleoclimate，Chemical Geology 等期刊上。目前为罗格斯大学（Rutgers University）博士后，用有孔虫壳体中的钠钙比研究新生代海洋主量元素的浓度变化，以及它与同时期全球气候变化和大陆风化速率之间的关系。曾作为无机地球化学家参与国际大洋钻探计划西南太平洋航次（IODP 371），并将于2019 年参与东南太平洋航次（IODP 379T）。

遊雅堂 競馬

BGEG国家重点实验室

2018年12月3日