期刊
EARTH AND PLANETARY SCIENCE LETTERS
卷 198, 期 1-2, 页码 167-175出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S0012-821X(02)00521-6
关键词
HF-177/HF-176; zircon; sea water; geochemistry; ferromanganese composition
The Hf isotope composition of seawater does not match that expected from dissolution of bulk continental crust. This mismatch is generally considered to be due to retention of unradiogenic Hf in resistant zircons during incomplete weathering of continental crust. During periods of intense glacial weathering. zircons should break down more efficiently. resulting in the release of highly unradiogenic Hf to the oceans. We test this hypothesis by comparing Nd and Hf isotope time series obtained from NW Atlantic ferromanganese crusts. Both isotope systems show a decrease associated with the onset of northern hemisphere glaciation, The observed changes display distinct trajectories in epsilon(Nd)-epsilon(Hf) space. which differ from previously reported arrays of bulk terrestrial material and seawater. Such patterns are consistent with the release of highly unradiogenic Hf from very old zircons, facilitated by enhanced mechanical weathering. (C) 2002 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据