1887

oa South African Journal of Geology - The recognition of palaeorifting in mid- to late-Proterozoic terranes : implications for the exploration geologist

Volume 89 Number 2
  • ISSN : 1012-0750
  • E-ISSN: 1996-8590

 

Abstract

Recent studies of young rift systems have contributed much to our knowledge of continental rifting and its complexities. Furthermore, palaeorifting environments are being increasingly documented in Proterozoic terranes. Despite uncertainty regarding the relative importance of Wilson cycle tectonics versus ensialic orogeny in the formation of most Proterozoic orogenic belts, careful geologic work in many such belts, notably the Damarides, suggests that initially rifting environments were dominant.

Continental rifting tends to produce distinctive lithologic assemblages, petrochemical signatures, and basement-cover rock relationships, and also tends to spawn a distinctive spectrum of metal deposits.

However, the intense deformation and high-grade metamorphism that characterize the interior portions of Proterozoic orogens can grossly obscure these early geologic and metallogenic relationships. However, insights gained from careful study of less complex belts, and even certain Palaeozoic terranes can be utilized in exploration for metals in complex Proterozoic terranes.

Two ore types, sediment-hosted massive sulphide deposits and stratiform copper deposits, that are generated in continental rift settings, are of particular importance in terms of mid- to late-Proterozoic metallogeny. Examples of such deposits are known in both little metamorphosed and highly metamorphosed Proterozoic terranes and represent a major fraction of the base metal resources of the southern hemisphere.

Loading full text...

Full text loading...

Loading

Article metrics loading...

/content/journal/10520/EJC-1bb4dad59e
1986-05-01
2020-09-27

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error