METAMORPHISM is the mineralogical and structural (textural) adjustment of (dominantly) solid rocks to physical and chemical conditions which differ from those under which the rocks originated. Weathering and similar processes are conventionally excluded. The type of metamorphism depends on the relative values of temperature ( T ) , confining pressure (/*con)> pressure or chemical activity or fugacity of water (expressed generally as PHJO)* deformation or directed pressures (P^ir) and their variation with time {t). There is only a limited degree of interdependence of these controls and the metamorphic history of a rock is an expression of their mutual interaction with time (Fyfe, Turner and Verhoogen, 1958; Pitcher and Flinn, 1965). <...>

In the foreword of the volume Mantle Metasomatism by Menzies & Hawkesworth (1987), Boettcher stated that the concept of mantle metasomatism has been of immense heuristic value for Earth scientists. At that time, metasomatism was still strongly related to allochemical metamorphism, where chemical composition of the rock is changed by the additional or removal of material.

In this book, the authors present current research in the study of the classification, geology and exploration of asteroids and meteorites. Topics discussed include meteorites and their asteroidal parent bodies; the diversion and exploitation of ice-rich NEOs using the solar collector; radar characteristics of asteroid 33342 (1998 WT24); asteroid dimensions and the truncated pareto distribution; Hilda asteroids in the Jupiter neighborhood; and asteroid Apophis and 1950 DA.

In Chapter 2, Microseeps as Pathfinder and Regional Filtering Tool in Petroleum Exploration, Tedesco discusses the aid of microseeps in petroleum exploration. As shown in previous research (Tedesco, 1995), the use of surface geochemistry can enhance the probability of success from 10% to 60%.