A laboratory manual for introductory courses in optical mineralogy. The illustrations are bandw, but available in color on a video cassette from the author. Annotation copyrighted by Book News, Inc., Portland, OR
At a time when 'textural' evidence is regarded as being 'obvious' ( . . . ) it becomes more and more difficult to find illustrations or even descriptions of the arrangements of the various constituents of 'traumatized' rocks. It is helpful in consequence to advise geology students that the study of thin sections is not only concerned with the identification of their mineral content. To do so would mean they could not see the wood for the trees. Accurate identification of the indi vidual minerals that form rocks is fundamental in their description but the analysis of their textures and habits is also essential. Study of textural features enforces constraints upon the inter pretation of the origin and history of a rock. The analysis of micro textures cannot and should never be an aim in itself, out must be sup ported by qualitative and quantitative correlations with theories of petrogenesis. The aim here is to help the reader to bridge the gap between his observations of rocks unqer the microscope and petrogenetic theories. The habits or architectures of crystals in rocks may resemble those studied by metallurgists and glass scientists. Analysis of micro textures is undergoing change engendered by comparisonS between manu factured and hence minerals. This can be seen from the increased number of publications dealing with crystal ~rowth or deformation processes at microscopic scales to which the name of 'nanotectonics' has been applied.
Featuring over 250 contributions from more than 100 earth scientists from 18 countries, The Encyclopedia of Igneous and Metamorphic Petrology deals with the nature and genesis of igneous rocks that have crystallized from molten magma, and of metamorphic rocks that are the products of re-crystallization associated with increases in temperature and pressure, mainly at considerable depths in the Earth's crust. Entries range from alkaline rocks to zeolite facies - providing information on the mineralogical, chemical and textural characters of rock types, the development of concepts and the present state of knowledge across the spectrum of igneous and metamorphic petrology, together with extensive lists of both commonly used and little used terms and bibliographies.
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
With new chapters on volcanism, new appendices & sharper photos, together with extensive updating of the whole text, this new edition builds on the strengths of its predecessor.