Geology Reference
In-Depth Information
(a)
(b)
Figure 5.10.
(a) Spalling in granodiorite, near the Tooma dam site, Snowy Mountains, New South Wales.
(b) Detail of part of Figure 5.10a (X).
results of weathering. Because shallow groundwaters are ubiquitous, so is subsurface weathering.
Boulders of two-stage type are found wherever fracture patterns are suitable. They are widely dis-
tributed, and are developed in many and varied climatic conditions, as well as in several types of
bedrock (Chapter 12).
Though conveniently termed two-stage forms, earlier magmatic, thermal and tectonic events find
expression in the detailed morphology of boulders (Gagny and Cottard, 1980) (
Fig. 5.5).
Events that
