Chemical petrology is essentially the physical chemistry of rocks and
associated fluids, although it also borrows heavily from such other
sciences as mineralogy. In terms of fundamentals it is firmly grounded
in chemical thermodynamics and kinetics. In its treatment of terrestrial
environments it grades imperceptably into sedimentology, geochemistry,
and geophysics and in extraterrestrial environments into cosmochemistry.
It is one of the most important branches of planetology and meteoritics.
The unity of approach of thermodynamics and kinetics to processes in
these diverse environments is stressed in this book by numerous examples
which have been chosen to illuminate different aspects of the subject.
Thus we have discussed in some depth such problems as the genesis of
layered basic complexes, calc-alkaline batholiths, chondri tic
meteorites, and the surface-atmosphere interaction of the planet Venus
because these are important and because they are particularly good
illustrations of the chemical petrology approach. Considerable attention
also has been devoted to volcanic processes. In our treatment of
metamor- phism in particular, an attempt has been made to correlate and
integrate the vast number of recent experimental, theoretical, and field
studies. However, we have not attempted a comprehensive survey of all
known rock types or occurrences, nor did we review all the diverse
opinions and conclusions on the origins of controversial rocks. Instead
we have chosen to stress interpretations we regard as following most
directly from the evidence.