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What are these shapes?
March 21, 2013 11:35 PM   Subscribe

What is the geologic origin of these strange, very large shapes in Russia?

The whole region in question
Strange parallel hills to the north

Clearly postglacial in nature, but it seems that something strange and grand happened here sometime in the past.
posted by dunkadunc to Science & Nature (6 answers total) 4 users marked this as a favorite
 
Those are actually pine forests that were planted/preserved to protect the steppes. If you look closely, they're surrounded by farm land, and the big bands are just undeveloped forest.

More information.
posted by empath at 12:52 AM on March 22, 2013


I have looked carefully.

That might be why the forest was left there, but there is clearly a geologic landform going on as well. The lines running SW/NE sometimes contain ponds, and sometimes are there, but contain no forest.
posted by dunkadunc at 12:59 AM on March 22, 2013


Aah, info:

Scientists reckon the emergence of forest bands from the times of Quaternary. About a million years ago there happened the shifting of ice sheets on the earth. Heavy winter snowfalls didn’t totally melt in winter, thus forming big glaciers. When the warming began melted waters from Altai foothills rushed along old riverbed of the Ob to the north, but being stopped by ice sheet which was slowly abandoning its position they had to turn to the Irtiysh River. After continental ice had melted and waters had rolled down into the Polar Sea the then riverbed of the Ob emerged. Down the ready ways of ancient hollows flew contem­porary rivers: the Burla, the Barnaulka, the Kasmala, the Kulun­da; wonderful pine forests and unique belt forests appeared on the left thick sands.

If anyone has any more detailed info on this, that would be cool.
posted by dunkadunc at 1:18 AM on March 22, 2013


And these smaller lines are giant current ripples from when the ice dam finally broke.
posted by dunkadunc at 1:27 AM on March 22, 2013 [1 favorite]


Eskers?
posted by Confess, Fletch at 6:18 AM on March 22, 2013


I think not eskers, rather moraines and some geostatic rebound going on as well perhaps.
posted by humboldt32 at 11:28 AM on March 22, 2013


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