Physicists attempt to reduce natural phenomena to their essential dimensions by means of simplification and approximation and to account for them by defining natural laws. Paradoxically, whilst there is a critical need in geology to reduce the overwhelming field information to its essentials, it often re- mains in an over-descriptive state. This prudent attitude of geologists is dictated by the nature of the subjects being consi- dered, as it is often difficult to derive the significant parame- ters from the raw data. It also follows from the way that geolo- gical work is carried out....

This volume follows a Specialized Symposium on "Mantle denudation in slow spreading ridges and in ophiolites," held at the XII EUG Meeting in Strasbourg, spring 1993. During the meeting it was felt that the contribu tions to the Symposium justified a volume presenting its main scientific achievements. The present title of the volume shows that the center of inter est has slightly shifted with respect to the initial objective: in order to under stand the processes involved in accretion taking place at oceanic ridges, it is crucial to study the interaction between uppermost mantle and lower...

Ophiolites are key sources of information regarding the genesis and evolution of oceanic lithosphere. Over the past decades, the geological tudy of ophio lites has provided a wealth of insight into lithospheric processes and has proved to be an indispensible prerequisite to interpreting geophysical and other investigations of the crust underlying recent oceans. The Oman Ophiol ite offers the most complete and structurally undisturbed sections of the oceanic crust in vast, clean exposures. It is, therefore, most fortunate for the scientific community that Mhd. Kassim, Director General of...

Physicists attempt to reduce natural phenomena to their essential dimensions by means of simplification and approximation and to account for them by defining natural laws. Paradoxically, whilst there is a critical need in geology to reduce the overwhelming field information to its essentials, it often re mains in an over-descriptive state. This prudent attitude of geologists is dictated by the nature of the subjects being consi dered, as it is often difficult to derive the significant parame ters from the raw data. It also follows from the way that geolo gical work is carried out. Geologists...

Ophiolites are distinctive assemblages of malic to ultramalic rocks representing fragments of the oceanic lithosphere. Nicolas (tectonophysics, U. of Montpelier) establishes a global comparison between ophiolites and their various oceanic environments, to aid in understanding the physical processes

This book is completely in phase with the 1994 science.

This volume follows a Specialized Symposium on "Mantle denudation in slow spreading ridges and in ophiolites," held at the XII EUG Meeting in Strasbourg, spring 1993. During the meeting it was felt that the contribu tions to the Symposium justified a volume presenting its main scientific achievements. The present title of the volume shows that the center of inter est has slightly shifted with respect to the initial objective: in order to under stand the processes involved in accretion taking place at oceanic ridges, it is crucial to study the interaction between uppermost mantle and lower...

1.1. HISTORICAL DEVELOPMENT OF THE OPHIOLITE CONCEPT. Ophiolite, Greek for 'the snake stone', appears to have received its first written definition by Brongniart (1813) as a serpentine matrix containing various minerals. Later in 1821 and 1827, Brongniart determined that volcanic and gabbroic rocks were also present, associated with cherts, and he ascribed an igneous origin to the ophiolite. Amstutz (1980) gives an excellent exegesis of these early contributions and traces the further use of the term and concept of ophiolite. This concept had been forged in the western Alps and Apennines...