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File Created: 31-Aug-1987 by Larry Jones (LDJ)
Last Edit:  03-Mar-2021 by George Owsiacki (GO)

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NMI
Name LAWYERS PASS Mining Division Liard, Omineca
BCGS Map 094E034
Status Showing NTS Map 094E06W
Latitude 057º 18' 29'' UTM 09 (NAD 83)
Longitude 127º 22' 06'' Northing 6352856
Easting 598294
Commodities Uranium Deposit Types D06 : Volcanic-hosted U
Tectonic Belt Intermontane Terrane Overlap Assemblage, Stikine
Capsule Geology

The Lawyers Pass occurrence is located 8 kilometres southeast of Edozadelly Mountain, west of Lawyers Pass and 12 kilometres west-southwest of the Lawyers mine (094E 066), approximately 281 kilometres north of Smithers.

The showing lies on the eastern edge of the Sustut Basin. It is composed of mid-Cretaceous to latest Cretaceous nonmarine strata of the Sustut Group. The Sustut Basin is a successor basin to the larger Bowser Basin to the west. The Bowser Lake Group consists of Middle Jurassic to mid-Cretaceous marine and nonmarine strata. Both groups and underlying strata of Stikinia were deformed by northeast-verging folds and thrust faults of the Skeena Fold Belt in Late Jurassic(?) to latest Cretaceous or early Tertiary time (Geological Survey of Canada Paper 92-1A, pages 77-84).

Mid-Cretaceous to latest Cretaceous continental clastic sediments of the Sustut Group are subdivided into the Tango Creek and overlying Brothers Peak formations. The Tango Creek Formation is subdivided into two members: the Lower Niven Member and the Upper Tatlatui Member. The Brothers Peak Formation is subdivided into the Lower Lasuli Member and the Upper Spatsizi Member.

The Lower Lasuli Member is composed of coarse, grey, polymictic conglomerate and arenites, interbedded with grey, green and rarely varicoloured ash tuffs and tuffaceous mudstones and siltstones. The tuff units are radioactive with some zones 2 to 10 centimetres thick and over 500 metres strike length yielding over 0.01 per cent uranium (Geological Survey of Canada Paper 81-1A, page 245).

The lowermost six or seven ash tuff units of the Lasuli Member are anomalously radioactive. These tuffs are generally laminated, greenish grey, porcelaneous and hard, and weather cream to pale brown. The more radioactive tuffs and tuffaceous mudstones are marked by pink layers or mottles. The most radioactive are altered to a bright red, contain coaly fragments, and is within sequences containing white spherules and coalescent spherules of analcime (zeolites).

The Lawyers Pass occurrence is composed of radioactive materials in a tuff unit of the Lasuli Member. A sample of the tuff analyzed about 0.038 per cent uranium over a 2-centimetre thick layer. Radioactive inspection suggests that all tuffs in the Lasuli Member yielded about 0.002 to 0.006 per cent uranium. Uranium mineralization is likely early diagenetic, but essentially syngenetic within water-lain tuffs (Geological Survey of Canada Paper 81-1A, page 245).

Bibliography
EMPR MAP 65 (1989)
EMPR OF *1990-32, pp. 45,63,67,70
EMPR PFD 503035
GSC BULL 12; 270; 376
GSC OF 306; 483; 551
GSC P 71-1A, pp. 23-26; 72-1A, pp. 26-32; 74-1A, pp. 13-16; 76-1A, pp. 87-92; 77-1A, pp. 243-246; 80-1A, p. 348; 80-1B, pp. 207-211; *81-1A, pp. 241-246; 83-1A, pp. 221-227; 84-1A, pp. 105-108; *92-1A, pp. 77-84
GSC MAP 14-1973
Canadian Mineralogist Vol.12, pp. 527-541
Bell, R.T. (1985): Overview of Uranium in Volcanic Rocks of the Canadian Cordillera, in IAEA, Vol. ST1/PUB/690 - Uranium in Volcanic Rocks, p. 329

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