Search

This book involves application of the Calphad method for derivation of a self­ consistent thermodynamic database for the geologically important system Mg0- Fe0-Fe203-Alz03-Si02 at pressures and temperatures of Earth's upper mantle and the transition zone of that mantle for Earth. The created thermodynamic database reproduces phase relations at 1 bar and at pressures up to 30 GPa. The minerals are modelled by compound energy formalism, which gives realistic descriptions of their Gibbs energy and takes into account crystal structure data. It incorporates a detailed review of diverse types of experimental data which are used to derive the thermodynamic database: phase equilibria, calorimetric stud­ ies, and thermoelastic property measurements. The book also contains tables of thermodynamic properties at 1 bar (enthalpy and Gibbs energy of formation from the elements, entropy, and heat capacity, and equation of state data at pressures from 1 bar to 30 GPa. Mixing parameters of solid solutions are also provided by the book. Table of Contents Introduction to the Series....................................................................................... V Acknowledgments................................................................................................ VII Preface................................................................................................................... IX Table of Contents.................................................................................................. XI Co-Authors......................................................................................................... XIII Vitae of Co-Authors............................................................................................. XV CODATA Task Group on Geothermodynamic Data....................................... XXIII Chapter 1. Thermodynamics and Modeling.......................................................... 1 1. 1 Introduction....................................................................................... 1 1. 2 Thermodynamic Modeling................................................................ 1 1. 3 Experimental Data............................................................................ 3 1. 4 Programs and Assessment................................................................. 4 System and Phases............................................................................ 5 1. 5 Chapter 2. Experimental Phase Equilibrium Data................................................. 7 The Si02 System............................................................................... 7 2. 1 2. 2 The Fe-0 System.......................................................................

Considerable progress has been made in our understanding of the physicochemical evolution of natural rocks through systematic analysis of the compositional properties and phase relations of their mineral assemblages. This book brings together concepts of classical thermodynamics, solution models, and atomic ordering and interactions that constitute a major basis of such analysis, with appropiate examples of application to subsolidus petrological problems. This book is written for an audience with a senior undergraduate level background in chemistry. Derivations of fundamental thermodynamic relations which are in need of reemphasis and clarification are presented.

With the rapid development of fast processors, the power of a mini-super­ computer now exists in a lap-top box. Quite sophisticated techniques are be­ coming accessible to geoscientists, thus making disciplinary boundaries fade. Chemists and physicists are no longer shying away from computational mineral­ ogical and material science problems'too complicated to handle.'Geoscientists are willing to delve into quantitative physico-chemical methods and open those'black boxes'they had shunned for several decades but with which had learned to live. I am proud to present yet another volume in this series which is designed to break the disciplinary boundaries and bring the geoscientists closer to their chemist and physicist colleagues in achieving a common goal. This volume is the result of an international collaboration among many physical geochemists (chemists, physicists, and geologists) aiming to understand the nature of material. The book has one common theme: namely, how to determine quantitatively through theory the physico-chemical parameters of the state of a solid or fluid.

The second volume of this series consists of three parts. Part I focuses on the research on intracrystalline reactions. This work, which began nearly two decades ago, is critically reviewed by Ghose and Ganguly in Chapter 1. Besides the review, the authors include some of their previously unpublished work to demonstrate how future research could aid in obtaining data on thermodynamics of solid solutions and in understanding the cooling history of igneous and metamorphic rocks. The latter is also the theme adopted by Kretz in the second chapter, which examines the redistribution of Fe and Mg in coexisting silicates during cooling. Chapter 3 contains new data on Fe-Mg distribution in clinopyroxenes. Dal Negro and his co-authors have selected a series of clinopyroxenes from volcanic rocks and present site occupancy data on several clinopyroxenes of intermediate compositions. The data set has not been published before and is the first of its kind. Part II of this book begins with a chapteron melts by Gaskell, who explores the relationship between density and structure of silicate melts. This is followed by the synthesis of data generated in the U.S.S.R. by Shmulovich and his co-authors on fluids. Blencoe, Merkel and Seil present a thorough analysis of the phase equilibrium data on feldspars coexisting with fluids in the third chapter in this part.

The purpose of this volume is to present the latest planetary studies of an international body of scientists concerned with the physical and chemical aspects of terrestrial planets. In recent years planetary science has developed in leaps and bounds. This is a result of the application of a broad range of scientific disciplines, particularly physical and chemical, to an understanding of the information received from manned and unmanned space exploration. The first five chapters expound on many of the past and recent observations in an attempt to develop meaningful physical-chemical models of planetary formation and evolution. For any discussion of the chemical processes in the solar nebula, it is important to understand the boundary conditions of the physical variables. In Chapter 1, Saf­ ranov and Vitjazev have laid down explicitly all the physical constraints and the problems of time-dependence of nebular evolutionary processes. Planetary scientists and students will find in this chapter a collection of astrophysical parameters on the transfer of angular momentum, formation of the disk and the gas envelope, nebular turbulence, physical mixing of particles of various origins and growth of planetesimals. The authors conclude their work with important information on ev­ olution of terrestrial planets. Although symbols are defined in the text of the article, readers who are not familiar with the many symbols and abbreviations in astrophysical literature will find it useful to consult the Appendix for explanations.