Skip to Main Content
Book Chapter

Ores and Metamorphism: Introduction and Historical Perspectives

By
Frank M. Vokes
Frank M. Vokes
Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, Trondheim, Norway
Search for other works by this author on:
Published:
January 01, 1998

Abstract

The types of mainly metallic mineralization found in metamorphic terranes are reviewed and an attempt is made to define the genetic relations between the mineralization and the metamorphic events. The terms metamorphosed, metamorphic, and metamorphogenic as applied to ores are also considered.

The development of thought and the history of investigations on ores in metamorphic terranes are traced from the early work in the second half of the nineteenth century onward. Early conceptions of metamorphism as an ore-forming process (metamorphogenesis) were seemingly not followed up by their originators, contemporaries, or immediate successors and were neglected until comparatively recent years. The idea of metamorphism as a modifier of preexisting, mainly sulfidic, but also oxidic, mineralization won more immediate and general acceptance in the early decades of the present century. In North America, emphasis seems to have been mainly on the deformational aspects of the metamorphism, whereas elsewhere, especially in Europe, the textural and mineralogical results of the metamorphic recrystallization also received considerable attention and metamorphism as an ore-forming process had won a certain degree of acceptance. This difference in emphasis may perhaps be referred to the different views held regarding the initial genesis of the ores in the two regions.

The late 1940s and the 1950s witnessed a considerable revision of ideas on ore genesis, especially regarding strata-bound massive sulfide ores. A parallel revival of interest in the role of metamorphism, probably not unrelated to the foregoing, began in the early 1950s, to begin with concerning metamorphosed ores. However, new thoughts concerning metamorphogenesis related to granitization or ultrametamorphism as an ore-forming process began to be published.

The following decades witnessed an almost explosive increase in the number of publications dealing with the effects of metamorphism on ore mineralization of practically all types, but with a definite emphasis on sulfide ores of the strata-bound type. One of the most significant breakthroughs in this respect concerned the world-famous Broken Hill deposit, New South Wales, although the metamorphosed nature of ores in the Scandinavian Caledonides, the North American Appalachians, the Lachlan fold belt of eastern Australia, the Sanbagawa terrane of Japan, the Urals, and Proterozoic fold belts in southern Africa, have all been thoroughly documented.

In recent years, however, the interpretation of many massive sulfidic ores in metamorphic terranes as metamorphosed has been increasingly questioned, and syntectonic, metamorphogenic, origins have been advocated. There is obviously a great need to be able to distinguish more clearly between metamorphosed and metamorphogenic ores of all classes.

An overview of certain selected aspects of metamorphosed ores is also presented, concentrating mainly on those not covered by other papers in this volume and covering fabric changes during metamorphism, changes in mineralogy (including geothermobarometry), mobilization-remobilization, and structural-morphological aspects of metamorphosed orebodies.

You do not currently have access to this article.

Figures & Tables

Contents

Reviews in Economic Geology

Metamorphic and Metamorphogenic Ore Deposits

Frank M. Vokes
Frank M. Vokes
Volume Editor
Department of Geology and Mineral Resource Engineering Norwegian University of Science and Technology Trondheim, Norway
Search for other works by this author on:
Brian Marshall
Brian Marshall
Volume Editor
Department of Applied Geology University of Technology Sydney NSW 2007 Australia
Search for other works by this author on:
Paul G. Spry
Paul G. Spry
Volume Editor
Department of Geological and Atmospheric Sciences Iowa State University Ames, Iowa 50011 USA
Search for other works by this author on:
Society of Economic Geologists
Volume
11
ISBN electronic:
9781629490182
Publication date:
January 01, 1998

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal