The Arthur W. White Mine, Red Lake area, Ontario: Detailed structural interpretation the key to successful grade control and exploration

Abstract The Arthur W. White Mine (formerly Dickenson Mine) is a structurally controlled, hydrothermal gold deposit. A gold producer since 1948, it has, to December 31, 1990, processed 6.9 million (m) tons (T) of ore grading 0.45 ounces per ton gold (oz/T Au). As of December 31, 1991, Proven and Probable Ore Reserves were 3.2 m. T. at 0.32 oz/T Au. The mine is located just east of Placer Dome Inc. 's Campbell Mine, within the Cochenour-Gullrock Lake deformation zone. It is situated on the hanging-wall side of a southeast-plunging anticline in a sequence of metamorphosed Archean volcanic, sedimentary andplutonic rocks of the Red Lake greenstone belt. Ore-bearing structures, found mainly within basaltic rocks, are brittle within greenschist-facies rocks to the northwest, but become more ductile toward the southeast, in amphibolite-facies rocks. Within and proximal to these structures, carbonate and arsenopyrite alteration decreases, whereas biotite, actinolite, pyrite and pyrrhotite all increase to the southeast.
Ore and shear structures occur symmetrically about the northwest-trending, steeply southwest-dipping, flattening foliation. The three most common ore trends are on average: (A) northwest-trending with a 55 degree to 85 degree dip to the southwest; (B) north-trending with a 40 degree to 50 degree dip to the west; and (C) due east-west-trending with a vertical dip. In general, the dominant direction of economic gold concentrations are explained and thus predicted by considering deformation style (brittle or ductile), rock anisotropies such as bedding and lithological contacts, and direction/magnitude of relative block movement. Direction "A " can be found adjacent to both right- and left-handed faults. Direction "B" occurs with dominantly right-handed systems and direction "C" is found with predominantly left-handed movement. Major faults active prior to, during, and after ore formation can have offsets in the order of 2500 feet. Movements along these faults were transpressive while their conjugate breaks were dilatant, thus creating zones for alteration and ore solution emplacement. A series of faults, each with offsets up to 30 feet were established under lower temperature brittle conditions during late- to post-ore formation. In more complex zones, formed during more ductile deformation, these faults controlled the localized geometry and, thereby, the depletion and enrichment of ore shoots, causing a high nugget effect.
Although an important aspect of production planning and monitoring, grade control is also very important within a complex ore zone so that the nuggets are not missed. Detailed observation of structure at the hand-sample scale and detailed mapping at the slope scale give valuable clues to interpreting the structures on a mine-wide scale. Determining the relative movement along fault structures is very important so that using an action-reaction- type logic, potential dilatant areas can be predicted and targeted for development and diamond drilling.
Keywords: Exploration, Arthur W. White mine, Red Lake, Dickenson Mines Ltd.
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Summary: Responding to market developments, interest in locating deposits of wollastonite has grown significantly. The many occurrences in the Grenville marbles of Quebec can be grouped into disseminated-type and discordant vein-type deposits. Disseminated-type wollastonite occurrences have the disadvantages of lower grade, the need for more elaborate mineral separation, and failure to meet "long grain" technical specifications. Vein-type deposits have better grades and technical characteris...
Publication: CIM Bulletin
Author(s): Antoine Fournier, Karen St. Seymour
Keywords: Exploration, Geology, Wollastonite, Grenville marbles, Marbles, Industrial minerals.
Issue: 957
Volume: 85
Year: 1992
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Summary: This paper describes the use of Geographic Information Systems (CIS) as a tool for mineral exploration by using the Eskay Creek area of northern British Columbia as an example. Data entry, analysis and output are discussed. Examples of some of the capabilities of the technology are presented.
The main benefit of the technology is being able to perform complex and sophisticated searches of large and diverse data sets to highlight exploration targets. A GIS is a powerful data management tool...
Publication: CIM Bulletin
Author(s): Robert W. Plummer
Keywords: Computer applications, Geographic Information Systems, Exploration.
Issue: 957
Volume: 85
Year: 1992
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Summary: The Lindsley project was a program of deep drilling to test the contact down-dip from two nickel-copper deposits, one uneconomical and the other mined out. The role of Borehole Pulse EM (PEM) was to detect the higher grade, more massive sulphide zones if they were missed by a drillhole, and to help determine geometry if the zones were intersected. Two problems appeared as the PEM survey progressed: (1) conductivity-thickness as measured by the PEM did not always relate to economic sulphides...
Publication: CIM Bulletin
Author(s): D. Crone, T. Watts
Keywords: Exploration, Pulse EM surveys, Lindsley discovery, Falconbridge Ltd.
Issue: 957
Volume: 85
Year: 1992
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Summary: The Guide to the Evaluation of Gold Deposits reviews the successive evaluation steps in the domains of geology, engineering, and economics. The Guide analyzes, in a systemic perspective, the sequence of exploration, development, and evaluation work required to bring a mineral deposit to production. The aim is to identify the metal/mineralization losses and ore dilution that each work step contributes to the evaluation and mining process. The procedure allows one to maximize the income and...
Publication: CIM Bulletin
Author(s): Marcel Vallee, Denis Cote
Keywords: Exploration, Gold deposits.
Issue: 957
Volume: 85
Year: 1992
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Summary: In most mineral processing operations the term "audit" is usually reserved for the exercise of checking financial records and/or safety practices. While these activities are time-consuming, no one disputes their necessity or value. If these areas are subjected to such careful scrutiny, why is it that the same principles are not normally applied to critically examine process operation. After all, the operating efficiency of the plant impacts directly on the measures of profitability....
Publication: CIM Bulletin
Author(s): Andrew J. Neale, Brian C. Flintoff
Keywords: Mineral processing, Plant audit.
Issue: 957
Volume: 85
Year: 1992
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