Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42C02NW00037

Record: MDI42C02NW00037

General

Mineral Record Identification
Record Name(s)	Sandor Occurrence - 1993
Related Record Type	Simple
Related Record(s)
Record Status	Occurrence
Date Created	2000-Nov-23
Date Last Modified	2022-Sep-16
Created By
Revised By

Commodities

Primary Commodities: Diamond

Location

Township or Area: Lalibert

Latitude: 48° 12' 46.14" Longitude: -84° 50' 55.62"

UTM Zone: 16 Easting: 659805.94 Northing: 5342191.76 UTM Datum: NAD83

Resident Geologist District: Sault Ste. Marie

NTS Grid: 42C02NW

Point Location Description: South end of roadside outcrop painted with a maple leaf

Location Method: Field Visit with GPS

Access Description: Drive north along Highway 17 from the junction of highway 101 for a distance of approximately 32 km. The occurrence outcrops on the east side of the highway in a 4 m high outcrop.

Exploration History

1993-95: S. Surmacz and M. Hauseux - prospecting, sampling. 1996-2000: Spider Resources Inc. - sampling, mapping, 10-tonne mini bulk samples.

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	Spessartite	Xenolith - Rich	Host
Mafic lava flow-unsubdivided	2			Near

Lithology Comments

Dec 07, 2005 (A Wilson) - The lamprophyre has a fine-grained groundmass and hosts isolated mantle xenoliths of actinolite+talc+carbonate up to 1 m in size. The xenoliths characteristically show radiating actinolite bladed crystals and are rimmed with talc. Other xenoliths have carbonate cores and talcose rims. The xenoliths are characteristically round. The lamprophyre also hosts numerous supracrustal xenoliths.

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) - The original chemical analyses of the host rock returned values of 540 ppm Cr, 380 ppm Ni, 5.2 ppm Cs, 138 ppm Rb. In 1995 a sample of the dike returned one macrodiamond and 5 microdiamonds from a 18.1 kg sample. Two samples (31.6 kg and 36 kg) collected by Spider Resources in 1996 returned 10 and 54 diamonds respectively; 8 were macrodiamonds. To the end of 2000, a total of 97 diamonds, comprising 1 commercial stone, 13 macrodiamonds and 83 microdiamonds have been recovered from 308.6 kg. A 2.724 tonne bulk sample collected in 2001 by Spider returned 8 commercial sized diamonds (one dimension > 1 mm) and 3 additional macrodiamonds (one dimension > 0.5 mm). Second mini-bulk sample (2.476 tonnes) returned 3 commercial sized diamonds and 5 additional macrodimaonds from the westernmost outcrop of the showing. A third mini bulk sample of 2.41 tonnes returned 1 macrodiamond. All three bulk samples were collected within the Sandor structure.

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
Irregular		5		120				2703 MA	OFR 6016

Site Visit Information

Date: Nov 23, 2000

Geologist: A Wilson

Notes: The dike is easily distinguished from the surrounding bedrock but it cannot be traced more than 25 m along strike.

References

File - Resident Geologist files WP Rabazo-32, WP_Lalibert-02

Publication Number: Date:

Author:

Publisher Name:

Location: SSM RGP office

Map - Precambrian Geology, Lalibert Township

Publication Number: OFM0221 Scale: 1:15,840 Date: 1993

Author: Sage R.P.