为什么辉绿岩、辉绿岩防腐?- 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 - 07 - t12:16:19z //www.hoelymoley.com/feeds/question/17483 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/17483 4 为什么辉绿岩、辉绿岩防腐? MattGeo //www.hoelymoley.com/users/14316 2019 - 07 - 17 - t01:37:50z 2019 - 07 - 20 - t00:47:47z < p >辉绿岩通常被认为是相对耐蚀。我们通常可以找到辉绿岩堤坝横切不同地层地质景观,其中,辉绿岩岩脉或窗台上相当完整的结构,而周围地层侵蚀。< / p > < p >当然,微分风化和侵蚀取决于相对易感性在那些岩石相邻,但是如果你考虑到Goldich解散系列、辉绿岩和其他basalt-like机构不应该容易侵蚀?玄武岩和辉绿岩钙斜长石为主要矿物成分。< / p > < p >我可以看到页岩如何更快的天气和侵蚀但似乎不太可能,石灰石在干旱环境中或成熟的石英砂岩砂质岩永远会这样做。< / p > //www.hoelymoley.com/questions/17483/-/17518 # 17518 2 由Gimelist回答为什么辉绿岩、辉绿岩防腐? Gimelist //www.hoelymoley.com/users/725 2019 - 07 - 20 - t00:47:47z 2019 - 07 - 20 - t00:47:47z < p >辉绿岩确实相对防腐。其中一个原因是晶粒尺寸。< / p >

Consider the two other chemical equivalent of diabase: gabbro (coarse-grained) and basalt (glassy and fine-grained), which should potentially be similarly erosion resistant. This is not the case. Both gabbro and basalt erode very easily.

Coarse-grained rocks, in general, erode easily. The large grain size means it is relatively easy to dislodge individual grains out of the rock. You don't need a lot of water, for instance, to percolate between the not-many grain boundaries and release them. To make it worse, gabbros are full of minerals that are easily erodable such as plagioclase and olivine.

On the other hand, basalts also tend to weather easily. Having cooled fast, they are usually glassy which tends to crack during cooling. Glass is general is less resistant to chemical alteration than minerals, under similar conditions. Basalts also contain gas bubbles, which cause weakness spots in which the rock can break, leading to preferred weathering.

Diabase is fine grained, and contains no glass. It does not suffer from these two conditions. It is composed of very fine interlocking crystals that are very hard to dislodge, and is not penetrable by fluids.

That said, remember that it is all relative. A diabase will still weather faster than even the worst type of granite.

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