Publication Type:

Miscellaneous

Authors:

Schetselaar, Ernst; Pehrsson, Sally J.; Devine, C.; Lafrance, Bruno; White, Don J.; Malinowski, M.

Source:

A special issue on volcanogenic massive sulfide deposits of the Trans-Hudson Orogen, Economic Geology Publishing Company, Lancaster, PA, United States, Volume 111, p.877-901 (2016)

ISBN:

0361-0128

Keywords:

anticlines, Canada, Canadian Shield, classification, cores, corrections, deformation, faults, Flin Flon Belt, folds, foot wall, geometry, geophysical methods, geophysical profiles, geophysical surveys, hanging wall, host rocks, Hudsonian Orogeny, imbricate tectonics, lithostratigraphy, Manitoba, massive deposits, massive sulfide deposits, metal ores, Missi Group, molasse, North America, Paleoproterozoic, polyphase processes, Precambrian, proterozoic, Saskatchewan, seismic methods, seismic profiles, surveys, synclines, tectonics, three-dimensional models, thrust faults, two-dimensional models, upper Precambrian, volcaniclastics, Western Canada

Abstract:

Three-dimensional geologic modeling by integrated analysis and interpretation of drill core, 2-D and 3-D seismic, mine survey, and geologic map data provides new insights into the structural setting of the 85.5 million tonne (Mt) Flin Flon-Callinan-777 volcanogenic massive sulfide (VMS) ore system hosted in the Paleoproterozoic Flin Flon belt of Manitoba and Saskatchewan, Canada. The resultant camp-scale 3-D geologic model was, in addition to the densely drill intersected VMS-hosting mine horizon, constrained by lithostratigraphic reference drill holes intersecting the footwall and hanging-wall rock successions of the ore system, which were established by relogging 52 drill holes and systematically reconciling the lithofacies classes in their log descriptions with the lithofacies units of the 1:10,000-scale Flin Flon mining district geologic map. The lateral persistence and large stratigraphic range of these drill hole markers supported seismic interpretation and allowed tracing lithostratigraphic horizons and structures in areas with low drill hole density, expanding 3-D subsurface insight from the local to the more regional structural setting of the ore system.The overall 3-D modeled geometry and topological relationships between lithostratigraphic surfaces and multiple generations of thrust faults suggest that the Flin Flon mining district is underlain by an E-dipping stack of W-vergent thrust imbricates that formed during precollisional and collisional stages of the 1.9 to 1.8 Ga Trans-Hudson orogeny. The imbricate stack was subsequently deformed by E-trending ductile thrust faults that internally imbricated the Flin Flon arc assemblage and the molasse cover rocks of the Missi Group and brought up rocks of the former over the latter in a northerly direction. The VMS-hosting Millrock Member has been stacked on at least four structural levels, enhancing the VMS potential in the footwall and hanging wall of the known ore deposits where both thrust systems intersect.

Notes:

GeoRef, Copyright 2018, American Geological Institute.<br/>2016-070927<br/>777 Deposit<br/>Blue Lagoon Member<br/>Callinan Deposit<br/>Flin Flon mining district<br/>Millrock Member