- SMDI #
- 2160
- Current Showing Name
- Maw Uranium Zone, MAW Rare Earth Zone
- Historical Showing Names
- Maw Uranium Zone, MAW Rare Earth Zone
- Company Name
- Denison Mines Limited, Cameco Corporation, Agip Canada Ltd.
- Project Name
- UTM Easting (NAD83 Z13)
- 472593.0300
- UTM Northing (NAD83 Z13)
- 6369890.6000
- NTS Sheet
- 074H06
- TRM (Township-Range-Meridian)
- 98-22-2
- Primary Commodities
- Rare Earth Element (Unspecified)
- Associated Commodities
- Apatite, Arsenic, Cobalt, Copper, Lead, Nickel, Uranium, Zinc
- Discovery Type
- Drillhole
- Status
- Deposit: Advanced Exploration
- Geological Details
- Showing SMDI. 2160 or the "MAW" Zone is located approximately 31.5 km (19.6 miles) northeast of the Key Lake Uranium Deposits (SMDI. 1130 and 1131). This rare earth showing was discovered by prospecting.
At the MAW Zone, the Paleohelikian Athabasca Group Manitou Falls Formation can be readily divided into four major members:
(1) MFd: a interclast rich sandstone
(2) MFc: a medium-grained sandstone unit that contains pebble layers
(3) MFb: a coarse-grained sandstone, grit and pebbly sandstone and
conglomerate
(4) MFa a well sorted gritty sandstone interbanded with poorly sorted
conglomeratic sandstone and pebble conglomerate
Local disruptions in the sandstone units from drill hole to drill hole are a strong indication of post-Athabasca faulting.
The underlying Archean basement rocks consist of Upper Aphebian meta-arkose/granite gneiss, Lower Aphebian graphite-bearing metapelites and calcic metapelites (which may be overturned) and basal Archean granite gneisses and minor amphibolites. Basement uranium mineralization occurs only in the basement Lower Aphebian metasemipelites, pyritic-graphitic-metasemipelites and graphitic metasemipelites. Uranium mineralization and enrichment of metals occurs at the contact of graphitic units with other sedimentary facies. The MAW Zone alteration halo is 100 to 150 m (328.1 to 492.1 ft) wide and centres on the main massive graphitic conductor. Alteration extends up to 50 m (164 ft) into the basal sandstone. Basement and sandstone alteration features include bleaching, quartz dissolution, quartz overgrowths, drusy quartz, dravitization, illitization, kaolinization, chloritization and pyritization. The mineralized zone, a zone of intense hydrothermal alteration accompanied by strong fracturing and brecciation, alteration is characterized by carbon buttons, illite, hematite, limonite, and pyrite.
The main structural feature in the MAW Zone is a northeast trending thrust fault that has a vertical displacement of approximately 15 m (49.2 ft) at the unconformity. This thrust likely forms the locus for circulation of hydrothermal alteration and mineralizing fluids. At least three basement step faults (coincident with massive graphite gneisses) have been recognized. The step fault movement is both strike-slip and dip-slip. In the sandstone, the step faults form several series of northeast dipping splay faults which offset the sandstone sequence within a 100 to 150 m (328.1 to 492.1 ft) thick disrupted zone (characterized by rotated and tilted sandstone blocks). Two sets of faults, one dipping 20° to 30°SE and the other dipping 70° to 75°SE, occur near the unconformity. These fracture zones extend up to 100 m (328.1 ft) above the unconformity.
Mineralization occurs both in the faulted basal sandstone and in the underlying basement. There are two generations of mineralization present. The initial early hydrothermal alteration and mineralization produced a suite that includes sooty pitchblende, nickel arsenides and sulphates, chalcopyrite, pyrite, galena, sphalerite and associated apatite. A later generation of mineralization is characterized by pyrite, hematite and limonite. The deposit is viewed as an "unconformity-type" diagenetic-hydrothermal deposit rich in Y and REE. Normand (2014) provides a detailed description (p.62-68) of the hydrothermal, heavy rare earth element-rich, xenotime locations in the Athabasca Basin of which the Maw Zone is the best example.
- Geological Domain
- Wollaston
- Host Rocks
- Host Minerals
- Arsenopyrite
- Indicators
- Exploration History
- 6/20/1990 The showing area was first staked as CBS 5015 and CBS 5016. Agip Canada Ltd. Operated the property from 1978 to 1984. From 1978 to 1980, Agip completed an airborne INPUT and magnetic survey and follow-up ground program of geological mapping, radiometric prospecting, lake water/ sediment sampling, EM, magnetic, track etch surveys and 6 drill holes (AF 74H11-0017,-0018). From 1980 to 1981, Agip Canada completed gravity, DEEPEM, magnetic andbiogeochemical surveys and completed 16 reconnaissance drill holes on the ZP, ZR, ZT, ZWR and ZWS grids (AF 74H11-0029). In 1981, Agip Canada completed a VPEM survey over the O grid on CBS 5014 (AF 74H05-0073). In 1982, SMDC flew a gradiometer survey over the area (AF 73H11-0035 and 0081). Between 1982 and 1984, a Agip Exploration-E & B Exploration-SMDC joint venture completed EM, magnetic and radiometric surveys and prospecting and trenching and 6 drill holes (ZQ-7 to 11-83, ZQ-17-84) on the Q grid Maw Zone (AF 74H06-0080). In 1983, a regional prospecting program discovered the rare earth showing described as the "MAW" Zone or SMDI 2160. In 1984, SMDC completed an airborne INPUT and magnetic survey over the property (AF 74H11-0065).
In 1985, ML 5387 to ML 5392 were consolidated to ML 5473 and SMDC took over operatorship. SMDC completed ground UTEM surveys (AF 74H11-0066). On the MAW Zone (AF 74H11-0067). In this year, SMDC released a reserves calculation for the zone. In 1989, a partnership involving Cameco (66.6%) and E & B Explorations (33.3%) completed drill hole ZN-RE-1 on the Rare Earth Zone (AF 74H11-0076).
In 1992, ML 5473 was reduced and the showing was covered by S-105528. In the same year, a sandstone boulder sample survey was completed over the showing (AF 74H-0050). A second boulder survey was completed the following year (AF 74H-0051). In 1995, a partnership involving Cameco (40%), Denison Mines (40%), PNC Canada (10%), and Imperial Metals (10%) completed ground gravity, TDEM, and magnetic surveys on the Q and R-RE grids and drill hole ZQ-19 on the Q Zone (AF 74H-0052).
In 2001, a partnership involving Cameco, Denison Mines,and JCU Canada Exploration established grid WR-01-G1 over the showing then ran ground gravity, GPS,magnetic, and VLF-EM surveys on this grid (AF 74H11-0101). Between 2002 and 2003, they completed an airborne magnetic survey and spot satellite imaging that covered the showing (AF 74H11-SW-0104).
- Production History
- Reserves and/or Resources
- 1985-01-01
Maw Rare Earth Zone: contains an estimated 336,000 mt averaging 0.25% yttrium oxide.
Summary:
Maw Rare Earth Zone: Historic reserve (unspecified) of 336,000.00 tonne
- Yttrium: 336,000.00 tonne @ 0.25 %