DIAMOND PAGE — SouthernEra samples till at Back Lake

SouthernEra Resources (SUF-T) has resumed exploring the Back Lake project in the Northwest Territories. The company is attempting to find the source of glacially transported kimberlite boulders on the shore of Munn Lake, while, at the same time, further defining several kimberlite indicator mineral trains.

A large portion of the $1.5 million budgeted by SouthernEra for Territorial exploration in 1998-99 will be spent on the 70%-owned Back Lake project. Its two partners in the joint venture are Kalahari Resources (KLA-V), with a 19.38% interest, and Island-Arc Resources (IAR-V), with 10.62%. Kennecott Canada, an affiliate of Rio Tinto (RTP-N), holds a back-in right to a 30% interest from SouthernEra.

This past spring, SouthernEra drill-tested 10 high-priority ground geophysical targets at Munn Lake, up-ice of the Yuryi kimberlite float area, only to find a single 0.75-metre-wide kimberlite dyke.

On the basis of test-pitting, the company concluded that the likely source of the diamond-bearing kimberlite float material was up-ice, beneath Munn Lake, where a strong development of kimberlite mud is said to exist along the shoreline.

The Yuryi kimberlite was discovered last year during follow-up sampling on a strong kimberlite indicator mineral train. A 581.29-kg sample of weathered kimberlite, recovered from surface pits, yielded 62 macrodiamonds and 164 micros. (A macro is defined as measuring greater than 0.5 mm in at least one direction.) The largest recovered diamond weighed 0.12 carat, with one 0.03-carat and three 0.01-carat stones. Most of the diamonds are described as clear and colorless.

The kimberlite float exists in a 150-metre-diameter area of the Yuryi. Some of the larger kimberlite pieces range from 10 to 20 metres in diameter.

A 6-hole program near the Yuryi kimberlite find encountered kimberlite dykes ranging in thickness from 0.1 to 1.5 metres in four of the holes. A comparison of the chromite microprobe chemistry between the kimberlite dyke material and the kimberlite float suggests the two are not related.

In the spring, a 335-line-km grid was established, covering a portion of Margaret Lake, where a strong heavy mineral indicator was traced to the lake’s western shore. A 6-hole follow-up program to test five ground geophysical targets returned negative results.

In a bid to establish up-ice cutoffs for the Yuryi float and the Margaret Lake indicator trains, a sonic drill will be used to collect till material from the bottom of Munn and Margaret Lakes. A previous program of lake sediment sampling, carried out in conjunction with a bathymetric survey (lake-bottom depth), sampled only the surface of the lake bottom sediments.

The sonic drill will collect the entire bottom sediment sequence and can sample up to several metres of bedrock as well. As ice conditions are needed, the sonic drilling is not scheduled to start until mid-January of 1999.

In the meantime, SouthernEra is conducting till sampling in an effort to define three other weak indicator trains on the Back Lake property. About 300 samples will be collected.

SouthernEra holds interests varying from 10% to 100% in Territorial land holdings totalling 546,700 ha.

Kennecott is expected to carry out extensive exploration work on properties near Lac de Gras in which SouthernEra has interests.