|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Scientific Communications |
Department of Geology and Geological Engineering, Colorado School of Mines, Golden, Colorado 80401
AIRIE Program, Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523-1482
PRISE, Research School of Earth Sciences, The Australian National University, Canberra, ACT, Australia 02001
Cyprus Amax Minerals Company, 1501 West Fountainhead Parkway, Suite 290, Tempe, Arizona 85282
Corresponding author: e-mail,
mhitzman{at}mines.edu
The Kansanshi copper deposit in the Pan-African
Damaran-Lufilian fold belt of northern Zambia consists of high-angle,
sheeted quartz-carbonate-sulfide veins with envelopes of disseminated
sulfides. These veins cut and replace metamorphosed Katangan sedimentary
rocks of Neoproterozoic age. Crosscutting relationships have been used to
delineate three stages of subparallel veins. The first two vein sets are
chalcopyrite rich and contain minor molybdenite, and the third vein set
contains relatively abundant molybdenite with significant monazite and
brannerite and minor chalcopyrite. Direct dating of molybdenite (with
replicates) from each of the vein sets using the Re-Os method yields two
distinct ages, 512.4 ±
1.2 Ma and 502.4 ±
1.2 Ma (weighted averages, 2
),
consistent with the relative age relationships and vein mineralogies
observed in the field. The molybdenite-monazite veins, which crosscut the
two earlier chalcopyrite-rich vein sets, are distinctly younger (~10 m.y.),
based on Re-Os dating. SHRIMP U-Pb analyses of monazite from the final
veining event yield a U-Pb age of 511 ±
11 Ma. The 2
uncertainty of ±11
m.y. includes all ages and 2
uncertainties provided by the Re-Os method. These results indicate that
mineralization took place in the late Cambrian and suggest that either
mineralization was continuous for 10 m.y. or the Kansanshi deposit includes
two pulses of mineralization, one at ~512 Ma and one at ~502 Ma. Vein
mineralogies and clear crosscutting relationships favor the latter
suggestion. The ages of mineralization at Kansanshi are broadly similar to
those determined for other posttectonic vein systems in the central African
copper belt. Available geochronological data from deposits in the
Damaran-Lufilian orogen suggest that a major mineralization event occurred
throughout much of the Lufilian fold and thrust belt during and after peak
metamorphism and that mineralizing fluids responsible for the formation of
many of these deposits, including Kansanshi, may have been metamorphic in
origin.
This article has been cited by other articles:
|
|
 |
|
  H. A. El Desouky, P. Muchez, S. Dewaele, A. Boutwood, and R. Tyler Postorogenic Origin of the Stratiform Cu Mineralization at Lufukwe, Lufilian Foreland, Democratic Republic of Congo Economic Geology, May 1, 2008; 103(3): 555 - 582. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Morelli, R. A. Creaser, D. Selby, K. D. Kelley, D. L. Leach, and A. R. King Re-Os Sulfide Geochronology of the Red Dog Sediment-Hosted Zn-Pb-Ag Deposit, Brooks Range, Alaska Economic Geology, November 1, 2004; 99(7): 1569 - 1576. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Steven, N. Steven, and R. Armstrong A Metamorphosed Proterozoic Carbonaceous Shale-Hosted Co-Ni-Cu Deposit at Kalumbila, Kabompo Dome: The Copperbelt Ore Shale in Northwestern Zambia Economic Geology, August 1, 2003; 98(5): 893 - 909. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. E. Hanson Proterozoic geochronology and tectonic evolution of southern Africa Geological Society, London, Special Publications, January 1, 2003; 206(1): 427 - 463. [Abstract] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
