在一个缓慢扩散的山脊上,海洋地的生长日期
Joshua J Schwartz1, Barbara E John, Michael J Cheadle
1Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, USA.
Science (New York, N.Y.)
|October 29, 2005
概括
来自亚特兰蒂斯银行的加布罗斯的--约定揭示了海洋地形成的洞察力. 一些加布罗斯是在预测的海底年龄形成的,而另一些则表明石质层内的更深,更古老的结晶.
科学领域:
- 地质地质地质地质地质地
- 地质化学 地质化学
- 构造学 构造学 构造学 构造学
背景情况:
- 在缓慢扩散的山脊上形成海洋地是复杂的.
- 了解地生长过程对于板块构造学至关重要.
研究的目的:
- 限制西南印度山脊海洋地生长的时间和机制.
- 为了调查海洋下层地中异常古老的gabbros的起源.
主要方法:
- 在下层地 gabbros. uranium-lead-zircon的约会. 在下层地 gabbros.
- 来自印度西南山脊亚特兰蒂斯银行 (Atlantis Bank) 的加布罗样本的分析.
主要成果:
- 对于加布罗斯,获得了19个-年龄.
- 大约75%的加布罗斯在预测的海底磁年龄附近积累.
- 大约25%的gabbros产生了比预测更长的年龄.
结论:
- 这些发现表明,海洋地成分的轴内积累和更深,更古老的结晶的结合.
- 异常古老的加布罗斯可能是在地下5-18公里的深度形成的,后来被提升.
- 这项研究改进了在缓慢扩散的中心海洋地结构的模型.
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