(urth) Cumaean???

Pedro Pereira domus_artemis at hotmail.com
Sun Dec 16 03:36:07 PST 2007





From: mcquaryq at comcast.netDate: Sat, 15 Dec 2007 23:02:47 -0500To: urth at lists.urth.netSubject: Re: (urth) Cumaean???
Steve wrote: Then how explain the material Sev finds in the rock face?
 
If crustal material gets subducted and later emerges, it emerges as magma, not as pieces of old constructions. New material can be added to crust in two ways: either as vulcanic material  or added by accretion at the crustal base near subduction zones. The mountains themselves that form in this places are composed of crustal material already there, by compression, enrugation of local crust, etc. The new material is added from BELLOW those margins. 
 
So, if you want to find sedimentary rocks with "layers and layers" of vestigies of human occupation high in the mountains, then either it is in situ (depending on where exactely are they found) or it was "carried up" during elevation/rise of the mountains (and consequently deformed, etc.) 
 
Anyway, my opinion here as a geologist, and based on the fragmentary information provided, is that Wolfe is not beying very consistent or scientific in some cases. He takes a lot of artistic liberties, and in this case I guess he just picked up some geological notions that striked his fancy and somewhat missaplied them. Still, I does for great reading!
 
Pedro
 
 


On Dec 14, 2007, at 5:13 PM, Pedro Pereira wrote:
I'm a geologist. There's no "serious" geology going on between Severian's time and ours. South America seems to be basically the same as now. So there are no substantial destruction of human structures by subduction, that become part of the mantle and then eventually become part of the crust again during orogenesis. Orogenesis makes itself felt on the order of the millions of years, or hundreds of thousands of years, although its not so linear as that.

Steven
http://bowenfineart.com/
 
 
 
 
 
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