Structural evolution of the Hemlo greenstone belt in the vicinity of the world-class Hemlo gold deposit

Canadian Journal of Earth Sciences - Tập 40 Số 3 - Trang 395-430 - 2003
T.L. Muir1
1Precambrian Geology Section, Ontario Geological Survey, 933 Ramsey Lake Road, Sudbury, ON P3E 6B5, Canada (e-mail: ).

Tóm tắt

A complex history of volcano-sedimentary deposition, polyphase strain, multiple intrusive events, and various stages of porphyroblastesis is indicated for the Hemlo gold deposit area within the Hemlo greenstone belt. Structural elements can be assigned to at least six stages of development (D1–D6). D1 generated small-scale folds and low-angle faults (thrusts?) with no planar fabric, except within strain aureoles around the earliest intrusions. D2 was a progressive event resulting from northeast-directed compression, which generated regional, predominantly S-shaped folds (early D2); penetrative planar and linear fabrics, overturned stratigraphy, and formation of an inflection in the strike of the greenstone belt (mid-D2); and development of high-strain zones with dominant sinistral and local dextral shear sense (late D2). D3 was a distinctly separate progressive event resulting from northwest-directed transpression, which generated variably penetrative east- to northeast-striking foliation (S3), ductile dextral shear fabrics, and small-scale Z-shaped folds (early D3), followed by brittle–ductile to brittle development of cataclasite and pseudotachylite in layer-parallel zones (late D3). D4 resulted in contractional kinks and brittle fractures, locally in conjugate sets. D5 and D6 are represented by brittle to brittle–ductile faults, which overprint Paleoproterozoic and Mesoproterozoic dikes, respectively. Four granitoid magmatic events span the interval 2720–2677 Ma, with emplacement mainly during D2, between ca. 2690 and ca. 2684 Ma. A protracted period of regional medium-grade metamorphism likely spanned the D2–D3 stages. The Hemlo gold deposit was emplaced during mid-D2 and was largely controlled by D2 structural elements and competency contrast between rock units.

Từ khóa


Tài liệu tham khảo

Arias Z.G., 1990, Miscellaneous Paper, 150, 107

Ayer J., 2002, Precambrian Research, 115, 63, 10.1016/S0301-9268(02)00006-2

Bauer R.L., 1992, Canadian Journal of Earth Sciences, 29, 2087, 10.1139/e92-166

Beakhouse G.P., 1998, Open File Report, 5977, 1

Behrendt J.C., 1988, Geology, 16, 81, 10.1130/0091-7613(1988)016<0081:CSOTMR>2.3.CO;2

Bodycomb V., 2000, Extended Abstracts, 25, 1094

Buchan K.L., 1993, Canadian Journal of Earth Sciences, 30, 1286, 10.1139/e93-110

Buchan K.L., 1996, Canadian Journal of Earth Sciences, 33, 1583, 10.1139/e96-120

Cameron E.M., 1985, Geochimica et Cosmochimica Acta, 49, 2041, 10.1016/0016-7037(85)90062-6

Corfu F., 1989, Chemical Geology, 79, 183

Corfu F., 1989, Chemical Geology, 79, 201

Corfu F., 1998, Geological Society of America Bulletin, 110, 1467, 10.1130/0016-7606(1998)110<1467:SGBWSP>2.3.CO;2

Davis D.W., 1998, Ont., 5, 1

Davis D.W., 1998, Open File Report, 5977, 1

Easton R.M., 2000, The Canadian Mineralogist, 38, 287, 10.2113/gscanmin.38.2.287

Grasemann B., 2001, Journal of Structural Geology, 23, 715, 10.1016/S0191-8141(00)00108-5

Hagemann S.G., 2000, Reviews in Economic Geology, 13, 9

Hugon H., 1984, Miscellaneous Paper, 119, 212

Jackson S.L., 1998, Open File Report, 5977, 1

Jackson S.L., 1991, Special, 4, 405

Jirsa M.A., 1992, Canadian Journal of Earth Sciences, 29, 2146, 10.1139/e92-170

Knight J.T., 1993, Mineralium Deposita, 28, 436, 10.1007/BF02431601

Kretz R., 1983, American Mineralogist, 68, 277

Kuhns R.J., 1994, Economic Geology, 89, 720, 10.2113/gsecongeo.89.4.720

Lin S., 2001, Economic Geology, 96, 477, 10.2113/gsecongeo.96.3.477

Masliwec A., 1986, Miscellaneous Paper, 130, 107

McGill G.E., 1992, Canadian Journal of Earth Sciences, 29, 2118, 10.1139/e92-168

Michibayashi K., 1991, University of Western Australia Publication, 25, 90

Michibayashi K., 1995, Ore Geology Reviews, 10, 31, 10.1016/0169-1368(95)00004-L

Muir T.L., 1986, Miscellaneous Paper, 132, 95

Muir T.L., 1995, Ontario Geological Survey, Map 2629, Scale, 1, 20

Muir T.L., 2000, Ontario Geological Survey, Map 2614, Scale, 1, 50

Muir T.L., 2002, Ore Geology Reviews, 21, 1, 10.1016/S0169-1368(02)00066-5

Muir T.L., 1987, Miscellaneous Paper, 137, 117

Osmani I.A., 1991, Special, 4, 661

Pan Y., 1992, Economic Geology, 87, 1104, 10.2113/gsecongeo.87.4.1104

Pan Y., 1993, Canadian Journal of Earth Sciences, 30, 985, 10.1139/e93-082

Pan Y., 1995, Ore Geology Reviews, 9, 455, 10.1016/0169-1368(95)00003-K

Pan Y., 1991, Precambrian Research, 52, 53, 10.1016/0301-9268(91)90013-Z

Pan Y., 1991, Economic Geology, 86, 1626, 10.2113/gsecongeo.86.8.1626

Parker J.R., 2000, Open File Report, 6032, 22

Passchier C.W., 2001, Journal of Structural Geology, 23, 951, 10.1016/S0191-8141(00)00166-8

Peterson V.L., 1999, Canadian Journal of Earth Sciences, 36, 605, 10.1139/e99-013

Powell W.G., 1999, Canadian Journal of Earth Sciences, 36, 33, 10.1139/e98-078

Queen M., 1996, Canadian Journal of Earth Sciences, 33, 958, 10.1139/e96-072

Robert F., 1997, Australian Journal of Earth Sciences, 44, 329, 10.1080/08120099708728316

Robert F., 2001, Richards and R.M. Tosdal. Reviews in Economic Geology, 14, 111

Schmid R., 1981, Geology, 9, 41, 10.1130/0091-7613(1981)9<41:DNACOP>2.0.CO;2

Stein H.J., 2000, Abstracts with Programs, 32, A424

Tabor J.R., 1991, Canadian Journal of Earth Sciences, 28, 292, 10.1139/e91-028

Williams H.R., 1991, Special, 4, 485

Wyman D.A., 1989, Journal of Geophysical Research, 94, 4667, 10.1029/JB094iB04p04667

Zaleski E., 1999, Canadian Journal of Earth Sciences, 36, 945, 10.1139/e99-016

Thông tin
Thông tin xuất bản

Canadian Journal of Earth Sciences

Tập 40 Số 3

395-430

Thông tin tác giả