Petrotectonics

petrotectonics

[¦pe·trō·tek′tän·iks]

(geology)

Extension of the field of structural petrology to include analysis of the movements that produced the rock's fabric. Also known as tectonic analysis.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

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 It might be outdated or ideologically biased.

Petrotectonics

 

(also structural petrology), a division of petrography concerned with the structures of tectonites, that is, rocks that have undergone dynamic metamorphism. Petrotec-tonics was developed by the German scientist B. Sander in 1930.

In petrotectonics, spatially oriented specimens of the rocks under study are taken from geologic sections. The orientation of cleavage, of optic axes, and of other crystallographic elements in a large amount of grains of one or several minerals is measured in microsections of a Fedorov stage. These data are plotted on a stereographic net. The patterns of the resulting diagrams permit scientists to ascertain the symmetry and nature of the tectonic movements that caused the metamorphism. Experimental investigations of the mechanism of plastic deformation of various minerals and rocks under high hydrostatic pressures and temperatures are carried out for a more complete interpretation of the diagrams.

REFERENCES

Lukin, L. I., V. F. Chernyshev, and I. P. Kushnarev. Mikrostrukturnyi analiz. Moscow, 1965.
Sander, B. Einführung in die Gefügekunde der geologischen Körper, parts 1-2. Vienna-Innsbruck, 1948-50.
Turner, F. J., and L. E. Weiss. Structural Analysis of Metamorphic Tectonites. New York, 1963.

A. V. PEK

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