...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Regional crustal thickness and precipitation in young mountain chains
【24h】

Regional crustal thickness and precipitation in young mountain chains

机译：青年山地带的地壳厚度和降水

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Crustal thickness is related to climate through precipitation-induced erosion. Along the Andes, the highest mountains and thickest crust (approximately 70 km) occur at 25 degrees south, a region of low precipitation. Westerly winds warm passing over the Atacama Desert; precipitation is modest in the High Andes and eastward over the Altiplano. Severe aridity, hence low erosion rates, helps to account for the elevated volcanogenic contractional arc and high, internally draining plateau in its rain shadow. Weak erosion along the north-central arc provides scant amounts of sediment to the Chile-Peru Trench, starving the subduction channel. Subcrustal removal might be expected to reduce the crustal thickness, but is not a factor at 25 degrees south. The thickness of the gravitationally compensated continental crust cannot reflect underplating and/or partial fusion of sediments, but must be caused chiefly by volcanism-plutonism and contraction. Contrasting climate typifies the terrain at 45 degrees south where moisture-laden westerly winds encounter a cool margin, bringing abundant precipitation. The alpine landscape is of lower average elevation compared with the north-central Andes and is supported by thinner continental crust (approximately 35 km). Intense erosion supplies voluminous clastic debris to the offshore trench, and vast quantities are subducted. However, the southern Andean crust is only about half as thick as that at 25 degrees south, suggesting that erosion, not subcrustal sediment accretion or anatexis, is partly responsible for the thickness of the mountain belt. The Himalayas plus Tibetan Plateau, the Sierra Nevada plus Colorado Plateau, and the Japanese Islands exhibit analogous relationships between crustal thickness and climate.
机译：地壳厚度与降水引起的侵蚀与气候有关。沿着安第斯山脉，最高的山脉和最厚的地壳（约70公里）出现在南纬25度（降水少的地区）。西风吹过阿塔卡马沙漠；高安第斯山脉和高原北部向东的降水量很少。干旱严重，因此侵蚀率低，有助于解决火山阴影增加和内部排水平台高的问题。沿中北部弧线的微弱侵蚀使智利-秘鲁海沟的沉积物数量很少，使俯冲通道不堪一击。可能需要进行地壳下移来减小地壳厚度，但这不是南下25度的一个因素。重力补偿的大陆壳的厚度不能反映出沉积物的下陷和/或部分融合，而必须主要由火山岩-岩溶作用和收缩作用引起。相反的气候代表着南纬45度的地形，那里充满水分的西风遇到凉爽的边缘，带来了充沛的降水。与安第斯中北部相比，高山景观的平均海拔较低，并且由较薄的大陆壳（约35公里）支撑。强烈的侵蚀将大量碎屑碎屑提供给了近海海沟，并且大量被俯冲。但是，南部安第斯山脉的地壳厚度只有南下25度时的一半，这表明侵蚀是山腰带厚度的部分原因，而不是地下沉积物的沉积或沉积。喜马拉雅山加青藏高原，内华达山脉加科罗拉多高原和日本群岛显示出地壳厚度与气候之间的相似关系。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号