Geology Reference
In-Depth Information
(a)
(b)
Figure 2.10.
Dislocation along sheeting plane (a) in valley of Río Tabalón, Sierra Guadarrama, central Spain;
(b) in quarry at La Clarté, Brittany, France, with fault steps well-developed.
2.3.2
Endogenetic explanations
-Turning to endogenetic explanations, several writers, including some of the earliest to consider
the problems of sheet jointing, related sheet structure to the stresses imposed on magmas during
injection or emplacement and, hence, to the shape of the original pluton. The parallelism of sheet-
ing joints and the margins of the igneous body on Dartmoor were noted early last century. Some
workers attributed sheet structure to a combination of stresses developed during emplacement
of the granite mass and later cooling. Thus, although it may apply at a few sites, this suggestion
