There has been a great advance in the understanding of processes of
meta- morphism and of metamorphic rocks since the last edition of this
book appeared. Methods for determining temperatures and pressures have
become almost routine, and there is a wide appreciation that there is
not a single temperature and pressure of metamorphism, but that rocks
may preserve, in their minerals, chemistry and textures, traces of their
history of burial, heating, deformation and permeation by fluids.
However, this excit- ing new knowledge is still often difficult for
non-specialists to understand, and this book, like the first edition,
aims at enlightenment. I have concen- trated on the interpretation of
the plate tectonic settings of metamorphism, rather than following a
geochemical approach. Although there is an impress- ive degree of
agreement between the two, I believe that attempting to discover the
tectonic conditions accompanying rock recrystallization will more
readily arouse the interest of the beginner. I have used a series of
case histories, as in the first edition, drawing on my own direct
experience as far as possible. This m
