MINFILE Mineral Inventory

MINFILE Record Summary

MINFILE No 082ENW075

File Created:	29-Jan-1988	by	Larry Jones (LDJ)
Last Edit:	25-Jan-1996	by	Jay W. Page (JWP)

SUMMARY

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		NMI
Name	WESTBENCH, MADELINE LAKE, NKWALA	Mining Division	Osoyoos
		BCGS Map	082E052
Status	Showing	NTS Map	082E12E
Latitude	049º 30' 40''	UTM	11 (NAD 83)
Longitude	119º 38' 44''	Northing	5487640
		Easting	308496
Commodities	Uranium	Deposit Types	B08 : Surficial U
Tectonic Belt	Intermontane	Terrane	Overlap Assemblage, Plutonic Rocks

Capsule Geology

The WESTBENCH showing is a postglacial uranium concentration in the lake-bottom sediments of Madeline Lake. It is located approximately 1.0 kilometre northwest of Westbench, a subdivision of Penticton.

This is one of many young uranium occurrences discovered by D. G. Leighton & Associates Ltd. in the late 1970s. Work prior to the uranium moratorium in 1980 consisted of auger sampling. The area is underlain by granodiorite of the Jurassic Okanagan Intrusions.

The occurrence is recent, having formed from the interaction between uranium-rich groundwater and unconsolidated material containing organics or clay. This is a process which is believed to still be taking place. The source of the uranium is thought to be the surrounding igneous rocks, where groundwaters rich in carbonate and alkali ions have leached labile uranium from fresh rock exposed after glaciation.

Uranium enrichment occurs in lake-bottom sediments over an area measuring 16,800 square metres (Culbert, 1979). An auger hole intersected a 4.0-metre thick layer averaging 0.0168 per cent uranium with a 0.5-metre section averaging 0.0303 per cent uranium (Culbert, 1979). The uraniferous layer lies 2.5 metres below the surface (Culbert, 1979).

Other young uranium occurrences located nearby are NKWALA NORTH (082ENW087), NKWALA CENTER (082ENW088), NKWALA P. LINE (082ENW089) and NKWALA SOUTH (082ESW188).

Bibliography

EMPR OF 1990-32; 1994-8

EMPR RGS 29

GSC MAP 538A; 15-1961; 1701A; 1712A; 1713A; 1714A; 1736A; 7686G; 8521G

GSC OF 409; 736; 1969

CIM BULL 1978, Vol. 71, #783, pp. 103-110

IAEA TECDOC 322 (Surficial Uranium Deposits, Technical Document, Vienna, 1984), pp. 179-191

Bates, D.V.; Murray, J.W.; Raudsepp, V. (1980): Royal Commission of Inquiry, Health and Environmental Protection, Uranium Mining; Commissioners' Report, Vol. 1, pp. 35-36, 183-184.

*Culbert, R.R. (1979): Post-Glacial Uranium Concentration in South Central British Columbia, Royal Commission on Uranium Mining, Accession List #2109S01, 20 pages.

Culbert, R.R. (1979): Uranium Equilibrium - Disequilibrium as Observed in the Natural Environment in British Columbia, Royal Commission on Uranium Mining, Accession List #2017S, 15 pages with Appendices.

*Culbert, R.R. and Leighton, D.G. (1988): Young Uranium; in Unconventional Uranium Deposits, Ore Geology Reviews, Vol. 3, pp. 313-330.

EMPR PFD 760, 1024