Lyell Collection
Geological Society, London, Special Publications
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pearce, J. A.
Right arrow Articles by Gale, G. H.
Right arrow Search for Related Content
Geological Society, London, Special Publications; 1977; v. 7; p. 14-24;
DOI: 10.1144/GSL.SP.1977.007.01.03
© 1977 Geological Society of London

Identification of ore-deposition environment from trace-element geochemistry of associated igneous host rocks

J. A. Pearce & G. H. Gale

Department of Earth Sciences, The Open University, Milton Keynes, Buckinghamshire, England
Department of Mines, Resources and Environmental Management, Winnipeg, Manitoba, Canada

Synopsis: The tectonic environment of formation of volcanogenic massive sulphide deposits and porphyry tin and copper deposits can be identified from the geochemical characteristics of the associated igneous rocks. The ‘stable’ trace-element geochemistry (involving Ti, Zr, Y, Nb, Cr and rare-earth elements) and geology of metabasalts related to 12 massive sulphide deposits indicate that the deposits studied fall into four distinct classes. (1) Cyprus-type, including Cyprus, Oman and Betts Cove, possibly formed during the early stages of back-arc basin development; (2) Løkken-type, including Løkken and York Harbour, possibly formed at back-arc basin spreading centres; (3) Joma-type, including Joma, Røros and Bidjovagge, possibly formed in a small ocean of Red Sea type; and (4) Gjersvik-type, including Gjersvik, Buchans, Noranda and Lynn Lake, possibly formed during an early stage of island arc evolution (Gjersvik), later during island arc evolution (the Buchans Kuroko-type deposit) or in a Precambrian setting (Noranda and Lynn Lake). Deposits related to major ocean ridge crests appear to be small and relatively uncommon, perhaps because relatively few favourable sites for ore deposition exist in such environments.

The environment of intrusion of acid-intermediate igneous rocks can be deduced by use of diagrams based on the element Nb (e.g. SiO2 versus Nb). On this basis, tinbearing granites can be classified either as within-plate magmas (Nigeria) or as magmas from evolved volcanic arc settings (e.g. Bolivia, Cornwall and Indonesia); the latter group can be further subdivided geologically into postorogenic and back-arc extensional settings. Although the continental crust may play a significant role in the formation of tin deposits, the geochemical data presented here suggest that partial melting of tin-enriched mantle above a subduction zone may be the single most important genetic factor.





This article has been cited by other articles:


Home page
 Geological Society, London, Special PublicationsHome page
J. Saavedra, A. Toselli, J. Rossi, E. Pellitero, and F. Durand
The Early Palaeozoic magmatic record of the Famatina System: a review
Geological Society, London, Special Publications, 1998; 142: 283 - 295.
[Abstract] [PDF]