Skip to Main Content
Book Chapter

Chapter 10: Regional- to Deposit-Scale Geologic Controls on Copper-Silver Mineralization in the Kalahari Copperbelt, Botswana

By
Wesley S. Hall
Wesley S. Hall
1
Colorado School of Mines, 1516 Illinois Street, Golden, Colorado 80401, USA
Search for other works by this author on:
Catherine Knight
Catherine Knight
2
Cupric Africa, Corner of Van der Linde and Smith Roads, 2
nd
floor, Bedford Square Office Suite, Bedford Gardens, Bedfordview 2008, Republic of South Africa
3
Khoemacau Copper Mining (Pty) Ltd., Fairgrounds Financial Center, Ground Floor Block 3, Plot 50374, Gaborone, Botswana
Search for other works by this author on:
David J. Catterall
David J. Catterall
4
Blue Clay Agencies (Pty) Ltd., Plot 431 Disaneng, Maun, Botswana
Search for other works by this author on:
Clemens Augenstein
Clemens Augenstein
5
Model Earth, Global Geological Services, Unit 2, 80 Colin Street, West Perth, Western Australia 6005, Australia
Search for other works by this author on:
Brett M. Davies
Brett M. Davies
6
Renaissance Geology Pty. Ltd., PO Box 111, Mundaring, Western Australia 6073, Australia
Search for other works by this author on:
John Deane
John Deane
2
Cupric Africa, Corner of Van der Linde and Smith Roads, 2
nd
floor, Bedford Square Office Suite, Bedford Gardens, Bedfordview 2008, Republic of South Africa
Search for other works by this author on:
Batanani Muyoba
Batanani Muyoba
3
Khoemacau Copper Mining (Pty) Ltd., Fairgrounds Financial Center, Ground Floor Block 3, Plot 50374, Gaborone, Botswana
Search for other works by this author on:
Oarabile Disang
Oarabile Disang
3
Khoemacau Copper Mining (Pty) Ltd., Fairgrounds Financial Center, Ground Floor Block 3, Plot 50374, Gaborone, Botswana
Search for other works by this author on:
Poul Emsbo
Poul Emsbo
7
U.S. Geological Survey, Box 25046, MS-973, Denver Federal Center, Denver, Colorado 80225, USA
Search for other works by this author on:
Yaoguo Li
Yaoguo Li
1
Colorado School of Mines, 1516 Illinois Street, Golden, Colorado 80401, USA
Search for other works by this author on:
M. Stephen Enders
M. Stephen Enders
1
Colorado School of Mines, 1516 Illinois Street, Golden, Colorado 80401, USA
2
Cupric Africa, Corner of Van der Linde and Smith Roads, 2
nd
floor, Bedford Square Office Suite, Bedford Gardens, Bedfordview 2008, Republic of South Africa
Search for other works by this author on:
Murray W. Hitzman
Murray W. Hitzman
1
Colorado School of Mines, 1516 Illinois Street, Golden, Colorado 80401, USA
Search for other works by this author on:
Published:
January 01, 2018

Abstract

The Kalahari Copperbelt in northwestern Botswana is characterized by structurally controlled, stratabound, mineralogically zoned copper-silver deposits hosted along a major redox boundary within a late Mesoproterozoic rift succession. Copper-silver mineralized rocks occur on the limbs and in the hinge positions of regional-scale folds that characterize the Pan-African Ghanzi-Chobe zone fold-and-thrust belt. Regional facies changes along the base of the transgressive marine D’Kar Formation, the host to the majority of mineralized rocks, delineate a series of synsedimentary basin highs and lows. The facies changes were identified through both lithostratigraphic analysis of drill holes and along-strike variations in magnetic lithostratigraphy, a technique that correlates the magnetic fabrics of second vertical derivative aeromagnetic maps with changes in lithostratigraphy. Basin highs controlled the development and distribution of favorable lithostratigraphic and lithogeochemical trap sites for later sulfide precipitation. Major facies changes across the Ghanzi Ridge area straddle a significant crustal structure identified in gravity datasets that appears to have influenced extensional activity during basin development.

During basin inversion, the basin highs, cored by rheologically stronger bimodal volcanic rocks, localized strain within mechanically weaker rock types of the Ghanzi Group metasedimentary rocks, leading to the development of locally significant permeability and the formation of structural trap sites for mineralization by hot (250°–300°C), oxidizing, metalliferous Na-Ca-Cl brines. Structural permeability was maintained within trap sites due to silicification and/or feldspar alteration during progressive deformation and associated hydrothermal mineralizing events.

You do not currently have access to this article.

Figures & Tables

Contents

Metals, Minerals, and Society

Society of Economic Geologists (SEG)
Volume
21
ISBN electronic:
9781629496405
Publication date:
January 01, 2018

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