News that Monopros has commenced a bulk-sampling program on the diamondiferous Victor kimberlite pipe in the James Bay Lowlands of northern Ontario is sparking renewed interest in the region.
The March 2000 issue of Diamond Focus, the Canadian newsletter of
Monopros is collecting a 10,000-tonne bulk sample of the Victor pipe, one of 20 kimberlites found about 90 km west of the town of Attawapiskat. The company owns the rights to 18 of these bodies, 16 of which have been drilled. The largest of these, at more than 10 ha, is the Victor pipe. Victor underwent testing for macrodiamonds in 1997 and 1999.
The 10,000-tonne bulk sample consists of 2,500 tonnes, collected using a large-diameter (24-inch) drill, with a further 7,500 tonnes taken from two surface trenches. The bulk sample will be processed on-site this spring and summer in a temporary 10-tonne-per-day diamond recovery pilot plant involving crushing, scrubbing, sizing, dense-media-separation and X-ray sorting.
This year’s winter work has required the construction of an 80-person campsite, a 3.3-km extension to an existing winter road and a temporary winter airstrip. The bulk-sampling and delineation drilling program will enable Monopros to predict a modelled grade, value and resource estimate for the Victor pipe.
The James Bay Lowlands have long been thought to be the source of indicator minerals and alluvial diamonds found as far south as Indiana state and in glacial sediments surrounding the Great Lakes. James Bay is thought to be at the apex of a glacial dispersion fan along which diamonds were carried by continental ice sheets. Surveys conducted by Selco Exploration and the Canadian Rock Company in the 1960s and by the Ontario Division of Mines in 1975 recognized 53 pyrope grains in 32 sites in the James Bay Lowlands, near the Kapuskasing High, a positive gravity anomaly that extends from Chapleau to Moosonee.
The James Bay Lowlands was an exploration hotspot in the early 1990s, involving such companies as KWG Resources, Spider Resources, Ashton Mining of Canada, Continental Precious Metals, Jonpol Explorations, Noront Resources, Garde Mining Exploration, Glencairne Explorations and Strike Minerals.
Through 1993 to 1997, two distinct ages of kimberlites were identified on the joint-ventured Spider No. 1 property, held by KWG and
Ashton was involved in the Spider No. 1 joint venture in its early years. The MacFayden No. 1 and No. 2 bodies and the Kyle Lake body were discovered in 1994. A 163.6-kg aggregate sample of diatreme facies kimberlite from MacFayden No. 1 returned 7 micros and 2 macros
Xenoliths
The Kyle Lake body, however, showed a strong macrodiamond count in two zones. A total 151.4 kg of sample returned 88 micros and 31 macros measuring greater than 0.5 mm. A 283-kg sample from the second hole in Kyle Lake intersected a complex kimberlite diatreme containing numerous xenoliths and yielded 291 micros and 79 macros.
Ashton drilled a further two holes into the Kyle Lake No. 1 body in 1995 and recovered 1.8 tonnes of material for macrodiamond testing. The MacFayden No. 1 kimberlite was further tested with one vertical hole that recovered about 1 tonne of sample. The results were disappointing. Kyle Lake was interpreted by Ashton to be a deeply buried, complex multi-phase body with an erratic, low diamond content (only seven stones measuring more than 0.85 mm were recovered), and no diamonds were recovered from MacFayden No. 1. Ashton relinquished its right to earn an interest in the Kyle Lake No. 1 body.
In subsequent work on the Kyle Lake No. 1 body, KWG and Spider recovered 10.2 tonnes of material from 11 drill holes. This mini-bulk sample was processed for a microdiamond count using caustic fusion analysis in some cases and gentle attrition milling followed by gravity separation in others.
During the 1995 spring season, KWG discovered the Kyle No. 2 and No. 3 kimberlite bodies, about 80 km north of initial Kyle Lake discovery. Both new bodies tested positive for microdiamonds. The discovery hole on Kyle No. 3 yielded 3 macros and 45 micros from 154 kg of material, whereas Kyle No. 2 returned 4 macros and 14 micros from a 552-kg sample. Under terms of the joint-venture agreement, Ashton elected to evaluate Kyle No. 3 further, and, in the process, recovered 1 macro and 18 micros from a 101.8-kg sample taken from a 52.5-metre-wide intercept.
Near-vertical
Based on the results of five holes, Kyle No. 3 was determined to be a near-vertical, dyke-like kimberlite body extending over a length of 450 metres. The western portion is 10-13 metres wide, ballooning to 120 metres wide in the centre before narrowing to 32 metres in the eastern end. An early 1996 KWG hole yielded 15 macros and 34 micros in a 57.4-kg sample.
In April 1996, after exploring the James Bay Lowlands for more than three years, Ashton sold its right to earn a 51% interest in the project to Spider for $1 million. Ashton retained a 25% back-in right to any discovery, excluding the original Kyle Lake No. 1 body.
Later that year, KWG and Spider announced the discoveries of Kyle No. 4 and No. 5 in the general vicinity of the Kyle Lake No. 1 body.
In more recent news,
Under a joint-venture agreement, Navigator can earn a half-interest in the Severn project from Canabrava by spending $1.7 million on exploration over two years, with a firm commitment to spend $1 million in the first year. Navigator is the operator of the project.
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