Block Mountains

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Block Mountains

 

swellings of the earth’s crust bound by tectonic faults.

Block mountains are characterized by massiveness, steep slopes, and comparatively smooth topography. They usually arise in folded zones that once had a mountain relief but have lost their plasticity and been smoothed by denudation. With repeated tectonic action these sections of the earth’s core do not form folds but break into separate blocks, some of which rise as horsts and begin to form ranges (“reborn mountains”), and others sink as grabens, forming depressions. Sometimes with repeated orogeny, the smoothed surface of the earth is subjected to plicate deformation, which leads to the formation of broad and gently sloping folds accompanied by faults (for example, the ranges of the Saiano-Altaiskii Oblast and the mountains of Central Europe).


Block Mountains

 

(fault-block mountains), mountains formed by folded rock strata broken along young fault lines into blocks that are uplifted to different heights. Block mountains are usually rejuvenated mountains and form within cratonic orogenic belts, as in the Tien-Shan and the Altai.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.