Experimental igneous petrology

Publisher Website
Google Scholar
Abstract
Experimental igneous petrology in the period 1971–1975 produced many exciting results that aided significantly our understanding of conceptual mechanisms involved in global‐scale tectonics. The investigation of melting and other phase relationships of rocks and synthetic systems ranging from intermediate to ultrabasic in composition, particularly in the presence of H2O and H2O‐CO2vapors, has established limits to conditions under which anatexis and phase transformations can occur, particularly at plate boundaries. Much of the H2O in the upper mantle and lower crust is bound in hydrous minerals such as amphiboles and micas; establishment of the conditions under which these phases are stable in the laboratory has provided the basis of several models for the genesis of orogenic zone calc‐alkaline rocks and for melting and other transformations of subducted lithosphere. Because of the significance of H2O, CO2, and other volatile components in upper mantle processes, considerable effort was devoted to the study of solubilities of these species in silicate melts at high pressures, and some thermodynamic data derived from measurements at high pressures and temperatures enabled the calculation of phase relations previously unobtainable. Many new experimental techniques were developed to extend the capabilities of reproducing natural conditions in the laboratory. Nevertheless, many more refinements and new developments must be made; for example, new alloys for encapsulation of Fe‐bearing samples must be sought.