三十亿年前大陆生长的地力学变化
Bruno Dhuime1, Chris J Hawkesworth, Peter A Cawood
1Department of Earth Sciences, University of St. Andrews, St. Andrews, UK. b.dhuime@bristol.ac.uk
Science (New York, N.Y.)
|March 17, 2012
概括
大陆地的生长涉及新地的形成和旧地的重新加工. 的同位素显示了持续的,但变化的地生长,可能与板块构造开始有关.
科学领域:
- 地质化学 地质化学
- 石化学 石化学是一门学科.
- 地球科学 地球科学 地球科学
背景情况:
- 了解大陆地的生长需要平衡新地的产生与旧地的重新加工.
- 使用-和同位素测定日期的,由于其氧同位素组成,是研究地再加工的关键档案.
研究的目的:
- 在不同年龄的中分析哈夫和氧同位素.
- 为了确定地球历史上重新加工和新的大陆地的相对比例.
- 为了研究大陆地在地质时间的增长速度.
主要方法:
- 在石中氧气同位素组成的分析.
- -和同位素约定石,以确定年龄限制.
- 同位素数据的相关性,以追踪地的演变.
主要成果:
- 在不同年龄组的中发现了和氧同位素的系统变化.
- 这些同位素变化提供了对新地和重新加工地之间随着时间的推移而变化的平衡的见解.
- 大陆地的生长被认为是一个连续的过程,其速度波动.
结论:
- 这项研究揭示了大陆地的连续增长速度,尽管是可变的.
- 观察到大约30亿年前地生长率的显著下降.
- 这种下降可能与潜水驱动板块构造学开始相关,从根本上改变地的动态.
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