TY - JOUR
T1 - Gold potential of the Mpanda Mineral Field, SW Tanzania: evaluation based on geological, lead isotopic and aeromagnetic data
AU - Stendal, Henrik
AU - Frei, Robert
AU - Muhongo, Sospeter
AU - Rasmussen, Thorkild M.
AU - Mnali, Saidi
AU - Petro, Faustin
AU - Temu, E. Brian
N1 - Funding Information:
The authors would like to acknowledge the financial support from the Danish Council for Development Research to the pilot project (RUF project 90953). The pilot project was named: An integrated approach to mineral exploration and environmental assessment in southern and eastern Africa––a pilot study in Tanzania, which was initiated by the Geological Survey of Denmark and Greenland (GEUS) in year 1999 ( Appel et al., 2000 ). The involved institutions were the Geology Department, University of Dar es Salaam (DGUDES), GEUS, the Geological Survey of Tanzania (GST), are thanked for their support, their general interest in the pilot project, and for their financial contributions. DGUDES and GST kindly provided cars and drivers for the fieldwork. The field team also wants to thank the regional and district commissioners for permission to do fieldwork in the region. The help from local wardens, field guides, and the various contact persons in Tanzania, including the Danish Embassy in Dar es Salaam, is highly appreciated. Journal reviewer (A. Möller) and comments by the editor, A.B. Kampunzu, were greatly appreciated and improved the article significantly. This work is published with permission of the Geological Survey of Denmark and Greenland.
PY - 2004/4
Y1 - 2004/4
N2 - Gold and base metals of the Mpanda Mineral Field (MMF) is the focus of this paper. Gold veins and gold-bearing base metal occurrences are structurally controlled by conjugate sets of NW-SE and E-W trending faults and/or shear zones that crosscut high-grade metamorphic rocks and post-kinematic intrusions. It was anticipated that Palaeoproterozic country rocks could have been potential host rocks for the gold mineralisation in this area. This argumentation was based on Pb model ages of various deposits from the MMF. Recent fieldwork and Pb isotopic results presented herein indicate that epigenetic gold and base metal vein-type mineralisation in the MMF is post-Palaeoproterozoic. Our Pb isotope study concentrates on constraining the sources of metals in gold-bearing quartz reefs and base metal occurrences. Pb isotopes of whole rocks and minerals indicate that mineralisation was emplaced during the Neoproterozoic, contemporaneous with the intrusion of alkaline granites and carbonatite complexes (e.g., Sangu-Ikola carbonatite complex) at ∼720 Ma. The source of Pb in the mineral occurrences is compatible with that characteristic of the Palaeoproterozoic host rocks. Aeromagnetic data suggest that the gold-bearing, NNW-SSE trending area continues to the north beyond Mpanda town. Pb isotope results and aeromagnetic data have significant implications for future exploration programs within the region, in that the search should potentially focus on the defined geophysical borders and trendlines, and on Neoproterozoic, rather than Palaeoproterozoic vein systems.
AB - Gold and base metals of the Mpanda Mineral Field (MMF) is the focus of this paper. Gold veins and gold-bearing base metal occurrences are structurally controlled by conjugate sets of NW-SE and E-W trending faults and/or shear zones that crosscut high-grade metamorphic rocks and post-kinematic intrusions. It was anticipated that Palaeoproterozic country rocks could have been potential host rocks for the gold mineralisation in this area. This argumentation was based on Pb model ages of various deposits from the MMF. Recent fieldwork and Pb isotopic results presented herein indicate that epigenetic gold and base metal vein-type mineralisation in the MMF is post-Palaeoproterozoic. Our Pb isotope study concentrates on constraining the sources of metals in gold-bearing quartz reefs and base metal occurrences. Pb isotopes of whole rocks and minerals indicate that mineralisation was emplaced during the Neoproterozoic, contemporaneous with the intrusion of alkaline granites and carbonatite complexes (e.g., Sangu-Ikola carbonatite complex) at ∼720 Ma. The source of Pb in the mineral occurrences is compatible with that characteristic of the Palaeoproterozoic host rocks. Aeromagnetic data suggest that the gold-bearing, NNW-SSE trending area continues to the north beyond Mpanda town. Pb isotope results and aeromagnetic data have significant implications for future exploration programs within the region, in that the search should potentially focus on the defined geophysical borders and trendlines, and on Neoproterozoic, rather than Palaeoproterozoic vein systems.
KW - Gold
KW - Mpanda mineral field
KW - Pan African mineralisation
KW - Pb-isotopes
KW - Tanzania
KW - Ubendian orogenic belt
UR - http://www.scopus.com/inward/record.url?scp=17644409055&partnerID=8YFLogxK
U2 - 10.1016/j.jafrearsci.2004.04.005
DO - 10.1016/j.jafrearsci.2004.04.005
M3 - Article
VL - 38
SP - 437
EP - 447
JO - Journal of African Earth Sciences
JF - Journal of African Earth Sciences
SN - 1464-343X
IS - 5
ER -