Harte, on 05 January 2013 - 03:43 PM, said:
Let's also not forget that rock is not metal.
If you heat stone to the point of plasticity, when it hardens it won't be the same stone anymore. Most stone will become basalt upon cooling.
The difference between basalt and andesite is chemical. Most rock becomes basalt because most rock is granite, its plutonic equivalent. You'll recall andesite's equivalent is diorite.
Quote
Also, many stones - such as limestone and sandstone, cannot be heated to the point of softening. Sandstone will just turn into glass (and i don't see any glass - I see plenty of sandstone.) Limestone will become simple lime (due to chemical reactions under the heat) and crumble away.
I should've thought of that about limestone. It's not like I wasn't discussing local limekilns with my brother recently. One thing though, under geological heat and pressure, limestone metamorphoses into marble, but that's more of a slow roasting. Likewise sandstone turns to quartzite. Following the rock cycle, IIRC, I think it'd turn into high-quartz granite or pure quartz if it were allowed to slowly crystallize, depending on the accessory minerals. That's all under sub-surface conditions of course.
As mentioned earlier, if those accessory minerals aren't present in the limestone part of the sample taken, they could only be added.
I was trying to find info on lava when I wrote that. Andesite is lava straight out of a volcano. How it cools dictates the crystal size and type. The quicker, the finer. I'm not convinced the vit layer wouldn't be deeper if the rock were remelted.
Edited by Oniomancer, 05 January 2013 - 05:16 PM.
"Apparently the Lemurians drank Schlitz." - Intrepid "Real People" reporter on finding a mysterious artifact in the depths of Mount Shasta.