Ontario Mineral Inventory

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Ontario Geological Survey
Permanent Link to this Record: MDI42C02NW00033

Record: MDI42C02NW00033

General

Mineral Record Identification
Record Name(s)	Lal-161 Occurrence - 1997
Related Record Type	Simple
Record Status	Occurrence
Date Created	2000-Nov-24
Date Last Modified	2021-Dec-14
Created By	A Wilson
Revised By	A Wilson

Commodities

Primary Commodities: Diamond

Location

Township or Area: Lalibert

Latitude: 48° 13' 11.77" Longitude: -84° 54' 3.52"

UTM Zone: 16 Easting: 655906.99 Northing: 5342875.78 UTM Datum: NAD83

Resident Geologist District: Sault Ste. Marie

NTS Grid: 42C02NW

Point Location Description: Stripped and trenched outcrop on south side of bush road

Location Method: Field Visit with GPS

Access Description: Drive north along Highway 17 from the junction of highway 101 for a distance of approximately 34 km to the intersection of the westward heading McCormick Lake Road and the eastward heading Magpie Mine Road. Drive along the McCormick Lake road for approximately 4.5 km to the stripped area.

Exploration History

1996-97: Spider Resources Inc. - sampling, mapping, stripping, trenching.

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Michipicoten

Geological Age: Neoarchean Geochronological Age: 2703 MA Geochron. Age Ref.: OFR 6016

Geology Comments

Dec 07, 2005 (A Wilson) - The diamond occurrences appear to be restricted to a D1 recumbent nappe in the west-central portion of the Michipicoten greenstone belt. The nappe is imbricated by south-vergin reverse faults. The direction of nappe transport is from south to north and it lies immediately north and adjacent to the Kapuskasing Structural Zone. This thrusting and shortening may be related to the tectonic events along the Kapuskasing Structural Zone. The western limit of the nappe is likely the Dickenson Lake fault that passes to the west of the Dickenson Lake stock. The nappe is not likely to extend east beyond the Marsden Fault. While lamrophyre dikes favourable to hosting diamond and ones that cut the diamond-bearing lamprophyres are commone east of the Dickenson Lake stock, they are absent west of the the stock.

Lithology

Lithology Data
Rock Type	Rank	Composition	Texture	Relationship
Lamprophyre-Unsubdivided	1		Xenolith-Bearing	Host
Intermediate Tuff	2		Tuff, Lapilli Tuff	Near

Lithology Comments

Dec 07, 2005 (A Wilson) - The dike is homogeneous, dark greenish-grey in colour and weathers to a medium greenish-grey. The dike is recessively weathered compared to the surrounding supracrustal rocks. The dike hosts approximately 10% xenoliths including both well-rounded acinolite-bearing xenoliths as well as irregularly shaped supracrustal xenoliths. The matrix of the dike is fine-grained. The supracrustal xenoliths are highly altered and often display reaction rims and altered cores. These supracrustal xenoliths are more commonly observed close to the contact with the surrounding supracrustal rocks. The tuff is very fine-grained and is strongly foliated.

Mineralization

Mineralization and Alteration
Rank	Mineral Name	Class	Economic Mineral Type	Alteration Mineral Type	Alteration Ranking	Alteration Intensity	Alteration Style
1	Diamond	Economic	Ore

Mineralization Comments

Dec 07, 2005 (A Wilson) - A 64.7 kg sample collected by Spider Resources in 1997 returned 5 microdiamonds and 4 macrodiamonds (total weight 666399 octocarats).

Mineral Record Details

Mineral Zones - Size and Shape

Rank: 1 Structure Type: None

Zone Name: Detour Lake - Rank 1
Shape	Length	Thickness	Depth	Strike	Dip	Plunge	Trend	Age	Reference
Unknown		4		335				2703 MA	OFR 6016

Site Visit Information

Date: Nov 24, 2000

Geologist: A Wilson

Notes: The western margin of the dike disappears into an adjacent swamp and the dike cannot be traced along strike for greater than 5 m.