Work History

Discovered during regional airborne radiometric surveying and staked as Nebulous cl 1-9 and 10-15 (YA5089) in two separate claims blocks during Jun/76 by Ukon Joint Venture (Chevron Canada Ltd and Kerr Addison Mines Ltd). The joint venture immediately carried out prospecting, staked Nebulous cl 16-29 (YA5142) in Jul/76 to form a single contiguous claim block and then completed detailed radiometric surveying and geochemical sampling before staking Nebulous cl 30-33 (YA5170) in Aug/76. The joint venture carried hand trenching, channel sampling and additional ground radiometric surveying in 1977 and blast trenching in 1980.
Restaked as Zulu cl 1-49 (YB67828) in Dec/95 by Mar West Resources Ltd.
In Apr/2000, Canadian United Minerals Inc staked Brenner cl 1-8 (YC19910) 3 km to the west-southwest and carried out reconnaissance geochemical sampling and prospecting later in the year; geochemical rock sampling in 2001; and magnetometer surveying and prospecting in 2003.

Capsule Geology

The occurrence is underlain by the mid Cretaceous Mount Brenner Stock of the Tombstone Intrusive suite, which has intruded Jurassic aged argillite and shale. Although shown on published maps as being syenitic in composition, detailed study by Lambert (1966) showed that the stock is actually monzonitic in composition and consists of four major concentric phases with a porphyritic quartz monzonite core. Three showings, named West, Ridge and East, occur over 250 m on the north-northwest flank of Mount Brenner and are collectively refered to as the Nebulous showings.
Mineralization at the Nebulous showings consists of a soft yellow, secondary(?) uranium mineral found coating joints and filling fractures within the host monzonite. It is often associated with a white precipitate, both of which fluoresce moderately to strongly green. A sample across 10 m assayed 0.015% U3O8, of which slightly more than half was contributed by the monzonite and the remainder was due to secondary enrichment.
The Brenner claims were staked to cover a magnetic anomaly near the contact between the Mount Brenner Stock and the intruded sediments. Two silt samples collected downstream of an east-west trending dyke, likely related to the Mount Brenner stock, returned weakly anomalous values for Au, Bi and Cu (peaks of 20 ppb, 6 ppm and 254 ppm, respectively). A grab sample of dyke material taken in 2000 returned 785 ppb Au, 316 ppm As and 36 ppm Bi, while followup sampling in 2001 returned only weakly anomalous values from the same dyke.

References

BREMNER, T.J., 1994. Proposed Tombstone Area Park: Preliminary Review of Mineral Potential. Indian and Northern Affairs Canada, Exploration and Geological Services Division, Open File 1994-2(T), 115 p.

CANADIAN UNITED MINERALS INC, Oct/2001. Assessment Report #094273 by S. Ryan.

CANADIAN UNITED MINERALS INC, Oct/2002. Assessment Report #094353 by S. Ryan.

GEOLOGICAL SURVEY OF CANADA Bulletin 180.

GORDEY, S.P. and MAKEPEACE, A.J., 2003. Yukon Digital Geology, version 2.0, S.P Gordey and A.J. Makepeace (comp.); Geological Survey of Canada, Open File 1749 and Yukon Geological Survey, Open File 2003-9(D).

LAMBERT, M.B., Apr/66. Geology of the Mount Brenner Stock. Unpublished M.Sc. thesis, University of British Columbia.

MINERAL INDUSTRY REPORT 1976, p. 141; 1977, p. 54-55.

UKON JOINT VENTURE, Mar/77. Assessment Report #090184 by A.R. Archer and E.P. Onasick.

UKON JOINT VENTURE, Dec/77. Assessment Report #090271 by Archer, Cathro and Associates.

UKON JOINT VENTURE, Jan/81. Assessment Report #090708 by A.R. Archer and W.D. Eaton.

YUKON EXPLORATION AND GEOLOGY 2003, p. 6.

YUKON GEOLOGY AND EXPLORATION 1979-80, p. 293.