Broken Rocks · Breccia II

Abstract

This volume is designed to illustrate textures and field identification problems associated with a group of fragmented rocks which are loosely termed “intrusive breccia”. The intrusive terminology is derived from their tendency to contain numerous rounded, milled fragments which exhibit evidence of upward transport and forceful injection to form pipe and branching dyke-like structures. The breccias are commonly hosts to overprinting economic mineralisation and with their tendency to reach maximum development within well-mineralised epithermal and porphyry environments, are of major exploration interest.