- SMDI #
- 1414
- Current Showing Name
- Leonard Mine
- Historical Showing Names
- Leonard Mine, Leonard Uranium Mine, Rix Athabasca No. 10 Adit
- Company Name
- Government of Saskatchewan, Saskatchewan Research Council
- Project Name
- UTM Easting (NAD83 Z13)
- 292220.7700
- UTM Northing (NAD83 Z13)
- 6607950.7700
- NTS Sheet
- 074N10
- TRM (Township-Range-Meridian)
- 122-16-3
- Primary Commodities
- Uranium
- Associated Commodities
- Copper, Iron, Lead
- Discovery Type
- Status
- Deposit: Post-Production [Institutional Control Program]
- Geological Details
- The Leonard Mine is located 3800 ft (1.16 km) southeast of the Smitty Mine or SMDI 1413 and 0.5 mile (0.8 km) northeast of the northeast end of Bertha Lake.
The Leonard Mine area is underlain by the northeast-trending, steeply east-dipping Tazin Group Jean Lake amphibolite which contains several sills of alaskite granite and interlayers of granitized siliceous rock, red granite, and pegmatite. K Ashton later re-mapped the host as a narrow northeast-trending band of quartzite with minor feldspathic quartzite (Murmac Bay Group unit Mq). To the east, the quartzites contact with pasmmitic to psammopelitic gneisses and migmatites (unit Ms) and, to the west, they contact with mafic volcanic and coeval gabbro derived amphibolite (unit Mv). This forms a prominent ridge between the Leonard and "201" faults. Seven sub-parallel tight, tension faults transect the country rock and join the major structures.
The deposit is a small high grade vein type deposit. Pitchblende, accompanied by galena, chalcopyrite, hematite, and pyrite occur in carbonate veins along the faults. Pitchblende also is coats breccia fragments within the wall-rock of the tensin faults and it is disseminated for a few feet into the wallrock of the vein.
Sampling of the best mineralized vein on surface revealed a 150 foot (45.7 m) length which averaged 0.38% U3O8 across 5.4 feet (1.7 m) and a 130 foot (39.6 m) length which graded 0.51% U3O8 across 2.2 feet (0.67 m). These two are separated by 73 feet (22.3 m) of vein material which fell below ore grade.
Underground exploration disclosed several pods of ore erratically distributed within the faults to a vertical depth of about 400 feet 121.9 m). Invariably, richest mineralization is where faults cut contacts between amphibolite and granite. Characteristic red alteration of wall rocks is common around radioactive veins. The mined ore shoot was 30 ft (9.1 m) wide, 40 ft (12.2 m) long and it extended to a vertical depth of 110 ft (33.5 m).
Approximately 1,000 ft (304.8 m) to the southwest of the main mine workings, Rix Athabasca drove the Rix No. 10 Adit to explore the western portion of one of the tension faults. The adit is underlain by granitic layered gneiss containing minor granite and pegmatite dykes and sills. No ore of appreciable value was encountered.
- Geological Domain
- Zemlak
- Host Rocks
- Host Minerals
- Hematite
- Indicators
- Exploration History
- 3/31/2022
ICR - 29 (No. 10 Adit) [CR-1012]
https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/mineral-exploration-and-mining/institutional-control-program
7/28/1988 In 1950, Rix Athabasca Uranium Mines Ltd. found 167 radioactive occurrences on the DD1 Concession during radiometric and geological surveys conducted over the concession. Fifty of these showings were considered worthy of further work. Three of these; the Smitty, Leonard, and No. 7 showings were eventually explored underground.
The Leonard Deposit was first explored underground in 1951 by a 381 foot adit (116.1 m) driven along the largest vein (AF 74N10-0124) but work was suspended when attention shifted to the Smitty Deposit in the following year, due to encouraging high-grade intersectons made by diamond drilling on the Smitty Showing.
Renewed interest was shown in 1955 and a small but very high grade ore shoot was mined above the adit level. This work warranted further expansion of the adit, and in 1956 the adit was widened and an internal shaft was sunk with lateral development on the 125 foot (38.1 m) and 250 foot (76.2 m) levels.
In 1959, the shaft was deepened to 872 feet (265.8 m) and two more levels were added. As a result of an agreement with the Eldorado Mill shipments of ore to the Eldorado Mill commenced in March 1958 and continued until 1960 when the ore zone became depleted.
Between 1951 and 1959, Rix Athabasca drilled many holes, totalling thousands of feet, to explore a 1 mile (1.6 km) long by 500 ft (152.4 m) wide section of the 201 Fault Zone. This east-west-trending fault zone, which is located immediately north of the Leonard Adit, is believed to be the north-controlling fracture of the ore zone in the Leonard Mine.
A summary of the assessment work completed by Rix Athabasca for this period is as follows:
1951: Leonard No. 1 zone and adit: 8 drill holes, adit and drift plans
(74N10-0103)
1952 to 1953: 4 drill holes in "Leonard Valley" area (AF 74N10-0104)
1957-1959: mine plans, surface & underground drilling, 201 zone (74N10-0098)
1957-1960: 1st level: geology, 20 drill holes (AF 74N10-0099)
1957-1960: 2nd level: 61 drill holes, 206 zone (AF 74N10-0100)
1959-1960: 3rd level: 12 drill holes (AF 74N10-0101)
1959-1960: 4th level: 12 drill holes (AF 74N10-0102)
In 1959, Rix Athabasca mapped the BOOM 10 Fraction and RIX 11 Fraction (AF 74N10-00105). By 1963, the adit was covered by CH claim No. 1 (S-81592).
In 1966, Mokta, a french owned company, drilled at least 20 diamond drill holes and 2 deeper ones over the western part of the '201' Fault Zone.
In 1968 to 1969, Amok, another french-owned subsidiary company, drilled at least 20 diamond drill holes over the entire zone which Rix Athabasca had drilled in the 1950's. The drilling activity completed in the 1960's did not reveal any extensions of ore zones found in the mine, and no further underground development was warranted at the time.
- Production History
- Production Period: 1951-01-01 to 1960-12-31
50,000.00 tons
The Leonard Mine workings consist of a main adit, and a shaft (located 100 m (328.1 ft) from the adit). The Leonard 10A workings, which are located 1.0 km (0.6 mile) north of the Leonard Mine,consist of a single adit.
In 1951, a 381 ft (116.1 m) adit was driven. Work was suspended. In 1955, a small very high grade pod was mined out above the adit level. In 1956, the adit was widened, an internal shaft was sunk, and lateral development commenced on two levels. Ore shipments to the Eldorado Mill commenced in March 1958. In 1959, the shaft was deepened to 872 ft (265.8 m) and and two deeper levels were added. Ore shipments continued until ore was depleted in 1960.
It is believed that about 50,000 tons of ore grading 0.20% U3O8 or better were mined and processed.
Summary:
- Uranium @ 0.20 %
- Reserves and/or Resources