Ultramafic and Ultrabasic Rocks

This chapter outlines the petrography of \nultramafic and ultrabasic rocks, and presents \na preliminary classification of the \npetrological associations in which they \noccur. Many of the associations, but not all \nof them, are described in detail in the following \nchapters. Within the classification \nthere is a guide to the chapters dealing \nwith the various associations, and for those \nassociations inadequately covered in this \nvolume reference is made to one or more \nreview papers. This is followed by O'Hara's \naccount of the mineral facies of ultrabasic \nrocks.