地球板块构造是怎样开始的?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 09 - t01:31:45z //www.hoelymoley.com/feeds/question/418 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/418 20. 地球板块构造是怎样开始的? Kenshin //www.hoelymoley.com/users/51 2014 - 04 - 22 - t09:04:12z 2019 - 12 - 06 - t23:30:52z < p >板块构造理论,描述了地球的岩石圈是由不同的板块,能够在底层的软流圈。在板块边界,这个运动能增加收敛可能发生俯冲边界,不同的边界,在熔岩上升不同板块之间以填补空白,或滑动板变换边界。< / p > < p >当我理解为什么我们采取这一理论,我不太清楚的是为什么地球的岩石圈是由这些不同的板块首先,和有可能对现有板块分成两个截然不同的盘子吗?有一个理论在地球板块最初是如何形成的? < / p > //www.hoelymoley.com/questions/418/-/463 # 463 6 kaberett回答的地球板块构造是怎样开始的? kaberett //www.hoelymoley.com/users/105 2014 - 04 - 23 - t17:26:03z 2014 - 04 - 23 - t17:26:03z < p >现有板块可以分裂:看,例如,在红海ridge-ridge-ridge三结/亚丁湾/东非裂谷带,虽然板块分裂也基本陆地覆盖如冈瓦纳的分手。< / p > < p >板块形式作为地球的对流系统的一部分:他们在地幔热传输的基础。当板块构造启动仍在辩论,但机制是很好理解的。冷却的岩浆海洋表面会形成块状(如果你想要一个人类大小的模拟,查看视频埃里伯斯火山的永久的熔岩湖,或夏威夷'ian流)。地幔只包含足够的水来充当润滑剂,促进形成剪切区,允许这些板块继续过去另一个而不是锁定(而金星的水浓度太低,因此缺乏板块构造)。< / p > < p >大陆和海洋岩石圈不同——特别是,一般来说更难点在大陆岩石圈的独特的“盘子”,部分原因是它生存更长的时间(最古老的海洋地壳ca 250 ma),因此有更复杂的历史对缝合/分手-认为喜马拉雅的增长。我的理解是,大陆岩石圈的形成的细节,而不是海洋岩石圈,仍然是一个活跃的研究领域。< / p > //www.hoelymoley.com/questions/418/-/464 # 464 21 丹尼尔回答的地球板块构造是怎样开始的? 丹尼尔 //www.hoelymoley.com/users/188 2014 - 04 - 23 - t17:31:05z 2014 - 04 - 24 - t17:03:01z < blockquote > < p >有一个理论在地球板块最初是如何形成的?< / p > < /引用> < p >这是源于另一个问题的答案你问到大陆地壳和海洋地壳之间的区别。< a href = " http://www.annualreviews.org/doi/abs/10.1146/annurev -地球- 060313 - 055016”rel = " noreferrer " >卡尔森et al。(2014) < / >只是提出一个优秀的回顾我们所知道的关于地球和它是如何形成的。我用它作为一个指导和这篇文章的来源。< / p > < p >最近一个锆石的年龄是决定4.374 Ga (< a href = " http://www.news.wisc.edu/22568 " rel = " noreferrer " >谷et al ., 2014 < / >)使用U-Pb地质年代学。地球的年龄是4.54±0.05 Ga。这个新的结果表明花岗质和长英质的岩浆已经出现在地球~ 1.6亿年后地球之后才形成的。一些其他有趣的日期是4.4到4.45之间的月球形成遗传算法,基于氙同位素的分离固体地球的大气层被认为发生在4.45 Ga。< / p > < p >地球形成后,形成的核心,从而创建一个金属内核和原始地幔。地球开始降温和分化,从而形成地壳。不同的模型建议等一系列的可能性似稳定的淬火地壳peridotitic / komatiitic成分(J.V.史密斯1981),一个非常进化成分接近石英闪长岩(哈里森,助教,2009)。

The question now is this crust now a plate or rather, similar to the lithosphere as we know it today? The lithosphere is defined as the brittle outer layer of the Earth and plates are segments of the lithosphere and the base of it is called the Mohorovičić discontinuity, which generally defines the contact between the lithosphere and the upper mantle. It is interesting to think about when these features may have formed as the Earth's outer crust is forming.

There is an entire GSA Special Paper volume on the subject of 'When Did Plate Tectonics Begin on Planet Earth?'. There is a range of evidence suggesting that plate tectonics as we know it today initiated at the latest around ~3 Ga to as late as ~1 Ga (Condie & Kröner, 2008). Below is a table from that paper that outlines indicators of plate tectonics.

Table from (Condie & Kröner, 2008) that reviews evidence of plate tecotnics.

The outer crust of Earth is likely not stationary, but possibly being dragged along the paths of mantle convection. These brittle segments begins colliding into one another and building upwards while other portions are subducted beneath other plate segments. The convecting mantle causes mantle material to be brought up from depth to conditions at lower pressures, which cause the mantle to melt (this is called adiabatic melting).

There was a paper just recently published in Nature by Bercovici and Ricard(2014) where they try to answer the question as to why we see geological evidence of proto-subduction at 4 Ga with for prominent subduction features appearing around 3 Ga. I suggest reading the abstract on the papers website but they suggest that ...

when sufficient lithospheric damage combines with transiet mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. - Bercovici and Ricard (2014)

On the composition of the crust...

The most incompatible elements in the mantle (e.g. lithophile elements [K,Na, Nd] and high field strength elements [U,Th]) will go into the liquid melt and move towards the surface of the Earth and either erupt on the surface or be stored in a magma chamber and further fractionate or differentiate to more felsic magma compositions.

Through time, all of these processes will generate different pieces of crust formed from different sources and at varying conditions and later become altered due to either chemical or physical metamorphism. Each of the continents we have today are pieced together from the separation and collision of other tectonic plates. For example, Pangaea was formed due to the collision of many different plates, I am not sure if Pangaea was then considered one giant plate, but it then broke apart and separated.

Is it possible for existing plates to split into two distinct plates?

The East African Rift is currently a divergent boundary within the African Plate. So the answer is yes.

//www.hoelymoley.com/questions/418/-/18601 # 18601 1 user18411回答的地球板块构造是怎样开始的? user18411 //www.hoelymoley.com/users/0 2019 - 12 - 01 - t00:22:45z 2019 - 12 - 01 - t01:50:20z < p >新(ish)工作问题:< a href = " https://www.nature.com/articles/s41598 - 018 - 33823 - y”rel = " nofollow noreferrer " > https://www.nature.com/articles/s41598 - 018 - 33823 - y < / > < / p > < p > tl,博士:“现代风格”板块构造可能(至少)与2.2 gy,可能开始2.5 gy。< / p > < p >扩大要求:< / p > < p >这篇论文不是paywalled。它是关于一个变质(通过改变温度和压力)岩石适合的政权通常是连接到高压/低温变形在一个俯冲带。政权是推断从矿物成分(基于假设某些矿物质或他们的缺席是一定条件下的标记)和日期由U / Pb衰变。metamorphisis事件因此约会的年龄2.1到2.2 Gy。假设相应的威尔逊循环必须早点开始,作者建议日期2.5 gy为现代风格的构造事件)早些时候(但不排除。< / p >
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