沉积物层堆栈年表——地球科学交流江南电子竞技平台江南体育网页版 最近30从www.hoelymoley.com 2023 - 04 - 05 - t23:53:18z //www.hoelymoley.com/feeds/question/940 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/940 10 沉积物层年表 杰森·博伊德 //www.hoelymoley.com/users/482 2014 - 05 - 15 - t23:54:53z 2014 - 05 - 21 - t03:11:29z < p >在新宇宙系列,尼尔羊毛脂泰森解释不同世界的时代已经确定,表明沉积的层在大峡谷是大量的化石记录地球的历史。他指出每一层是如何(显然)放在最后,显示不同阶段的年表的生物圈。< / p > < p >我记得学习科罗拉多河“雕刻”的峡谷,小时候在旅行。你可以想象这个——巨大的开放峡谷被侵蚀了数百万年,河床将凹槽变成巨大山谷,直到河边台地是分开的。但是,如果“雕刻”的峡谷,并不意味着沉积物层受到来自上层的层,按时间顺序?这一切是如何生命化石嵌在岩石,一度是一英里下表面,后来公开的河流的侵蚀?< / p > < p >我不怀疑科学,只是想了解形成的峡谷。< / p > //www.hoelymoley.com/questions/940/-/946 # 946 9 winwaed回答的沉积物层年表 winwaed //www.hoelymoley.com/users/44 2014 - 05 - 16 - t13:17:58z 2014 - 05 - 18 - t16:17:51z < p >简单大局而言,沉积物沉积首先从底部向上(理解)。然后该地区上升,河流侵蚀从上到下。< / p >

Most erosion is from the top down (there are scenarios such as dissolution and caves which are relatively rare exceptions). So here in Texas we find a large amount of the center of the state was covered with Cretaceous sediments which have since eroded away. We see signs of this from "outliers" - basically remnant caps of Cretaceous on the tops of hills.

As I say this is big picture viewpoint. The very bottom of the Grand Canyon has metamorphic rocks. And sedimentation will not have been continuous. There are gaps from erosion, uplift, etc. But yes the bottom is about 2 billion years old, and erosion of the canyon itself is "relatively" recent.

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