While still in the early stage of exploration, the lonore gold prospect in the James Bay region of north-central Quebec is shaping up to be quite a find.
In a first phase of drilling, which has been under way since August,
“The results have been spectacular and could signify a major new gold discovery in Quebec,” First Associates mining analyst Don Poirier states in a Nov. 29 research report. “We believe lonore is an important discovery for Virginia, presenting significant upside potential.”
A series of sub-parallel mineralized zones hosted in highly altered sediments were exposed by mechanized trenching earlier this summer and followed almost continuously over a lateral distance of 200 metres in a north-south direction. The mineralized zones, which reach up to 12 metres in width, have been systematically channel-sampled, producing impressive results in terms of both grade and continuity. Channel sampling shows consistent high-grade values ranging up to 19.75 grams across widths of 3-13 metres, with individual grab samples assaying as high as 80.7 grams.
Drilling so far has intercepted a steeply dipping, gold-bearing mineralized system over a strike length of nearly 300 metres and to a depth of at least 230 metres. Virginia is drilling off the discovery on 25-to-50-metre spacing. Thirty-eight holes have been reported, and the results show a highly uniform, well-mineralized system that has remarkable continuity from hole to hole. The system comprises at least two main zones, Roberto and Roberto Est, which remain open laterally and to depth. “Both zones are still very much alive,” says Paul Archer, Virginia’s vice-president of exploration.
Drilling has delivered consistent values in the range of 2.7-27.8 grams across intervals of up to 19.2 metres true width. Virginia has demonstrated the continuity of the Roberto zone over a lateral distance of 250 metres between grid lines 28+50N and 31+00N, and to a vertical depth of 230 metres, where the deepest hole (no. 34) intersected 14.5 grams across 7.7 metres (all true widths) on section 30+50N. At an average thickness of 4-5 metres, Poirier estimates the zone averages roughly 12 grams in grade, based on results from the first 23 holes.
The consistent nature of the high-grade mineralization is best illustrated section by section. On grid line 29+50N, where trenching returned 16.7 grams across 5 metres, Virginia stepped back and intersected:
— 13 metres grading 18.8 grams at a depth of about 50 metres in hole 2;
— 9 metres of 7.33 grams (including a 2.7-metre section of 14.6 grams) at about 100 metres from surface in hole 8; and
— 1.9 metres of 7.34 grams at 165 metres vertical depth in hole 28, the deepest drilled on this section.
Stepping out 25 metres along strike, where trenching had returned 6.12 grams across 6 metres on grid line 29+75N, Virginia encountered a 14-metre interval averaging 14.3 grams at 80 metres below surface in hole 9.
This was undercut by hole 14, which hit 8 metres of 9.89 grams (including a 4-metre interval of 14.8 grams) at roughly 125 metres vertical depth.
Hole 27 passed through a 6.6-metre section grading 6.62 grams (including a higher-grade 2.7 metres of 10.9 grams) at a depth of 170 metres. This sample interval contains up to 60% barren pegmatite material.
On section 30+00N, Virginia stepped back from a surface showing that ran 12.7 grams across 5 metres and intersected:
— 9.8 metres grading 7.77 grams (including a 2.7-metre interval of 14.8 grams) at 60 metres depth in hole 13;
— 4.5 metres of 10.6 grams (including a 2-metre section of 14.5 grams) at a vertical depth of 90 metres in hole 10;
— 5.8 metres of 8.6 grams, followed closely by a second lens in the footwall grading 3.6 grams across a core length of 7 metres in hole 22, 140 metres from surface; and
— a 0.7-metre interval of 4.97 grams at 190 metres vertical depth in hole 26.
The Roberto zone appears to be closing off to the north. Holes 19, 20 and 31 intersected an altered zone containing little mineralization and low gold values at depths of about 90, 120 and 175 metres vertically on section 31+25N. Results for hole 35, which tested the zone a farther 25 metres to the north at a vertical depth of 225 metres, are pending.
Though the Roberto zone may be cut-off, the drilling on grid line 31+25N has confirmed the northern extension of Roberto Est, a second distinct sub-parallel zone that lies some 50 metres east of Roberto. The drilling is designed to hit both zones. While hole 19 intersected no significant values in the zone at a shallow depth of 30 metres, hole 20 cut 12 metres grading 7.05 grams (including a 3.8-metre section of 14.1 grams) at a 70-metre vertical depth, and hole 31 hit 17 grams across 2.6 metres at a depth of 130 metres from surface.
The Roberto Est zone is traced at surface and by drilling over a distance of 250 metres between sections 28+75N and 31+25N. The zone is better developed in a 100-metre-long northernmost portion where two main lenses, called FW and HW, have been identified. Drilling shows good vertical continuity to a depth of at least 130 metres, based on the results of 15 holes. “Typical footwall and hangingwall widths are 4-8 metres and have a weighted average grade of approximately 9 grams gold per tonne,” states Poirier.
A 75-metre-long corridor of low or insignificant gold values isolates the southern end of Roberto Est, where results from another 10 holes show potential. A series of four holes drilled on section 29+25N intersected the mineralized zone to a vertical depth of 200 metres, and are highlighted by:
— 19.2 metres averaging 2.74 grams gold at 20 metres depth in hole 7;
— 1.9 metres of 4.98 grams occurring 45 metres from surface in the hangingwall of hole 29, followed by 2.9 metres of 6.54 grams in the footwall at a vertical depth of 60 metres;
— 5.1 metres of 11.5 grams in hole 30, about 80 metres from surface; and
— 7.58 grams across 4.1 metres in hole 15, the deepest intersection, at a vertical depth of 200 metres.
John Kaiser, publisher of the Bottom-Fishing Report, suggests lonore could contain a potential resource somewhere in the neighbourhood of 500,000 to 1 million oz., based on a preliminary back-of-the-envelope estimate.
As Virginia puts more holes into lonore, new zones are emerging. A quartz vein hosted in an altered diorite dyke and carrying several specks of visible gold was intersected by hole 23 in a new mineralized setting 60 metres east of Roberto Est. Hole 23, drilled in this, the Veine zone, returned 122 grams (or 3.6 oz.) across 0.8 metre. In follow-up drilling, hole 34 undercut this intercept by about 20 metres, hitting 34.7 grams across 2 metres. Holes 25 and 33, a farther 25 metres to the north, have also crosscut the narrow east-northeast-oriented mineralized structure, with intersections of 70.1 grams over 0.75 metre and 24.5 grams across 0.4 metre.
The wholly owned lonore project is 320 km northeast of the town of Matagami and covers 521 sq. km of the Ell Lake area in the eastern part of the Opinaca reservoir. The Opinaca reservoir can be reached by a 60-km-long gravel road off kilometre marker 395 of the James Bay paved road. It is then a 35-km-long journey by boat to the property, which is also accessible by helicopter or float plane from the Nemiscau airport, 100 km due south.
The project is in the Lower Eastmain belt, straddling the contact between two major tectonic stratigraphic assemblages, namely the volcanic rocks of the La Grande sub-province to the south and the sedimentary rocks of the Opinaca sub-province to the north. In the vicinity of the Opinaca reservoir, these rocks are intruded by syn-to-late tectonic dioritic and tonalitic plutons. This assemblage, or belt, of rocks is more than 25 km long and 3-4 km wide.
The lonore property block is centred on a discrete diorite-tonalite intrusion, measuring 10 km in diameter, at the northern margin of a vast batholithic complex and in the contact between the La Grande and Opinaca sub-provinces.
Ell copper showing
Virginia began reconnaissance work in the area in 2001 to evaluate the former Ell copper showing discovered by
An induced-polarization (IP) ground geophysical survey was conducted that winter over the area of the main showing, followed by additional prospecting and mapping in the summer of 2002. The discovery of several copper-gold-silver occurrences in the dioritic intrusion extended the mineralized system by another 2 km to the northeast. More importantly, this program led to the discovery of a different style of mineralization. A large, 2-metre-in-diameter, angular boulder of quartzo-feldspathic metasediment, with disseminated arsenopyrite and pyrrhotite, assayed 22.9 grams gold in a grab sample. Re-sampling of the boulder yielded 13.9 grams.
The 2003 exploration program at lonore was tailored to find its source. A new grid was cut on the northwest and north shores of Ell Lake and covered with ground magnetic, EMH and IP surveys at 200-metre spacing. A soil geochemical survey was also conducted utilizing mobile metal ion (MMI) analysis. Many additional boulders of mineralized metasediments were uncovered in an area measuring 4 by 2 km. Several of these boulders returned anomalous gold values above 500 ppb, with values as high as 19.03 grams.
Using a special backhoe brought in by helicopter, Virginia began an extensive stripping program in 2003 and exposed a limited portion of the probable source area of the boulders in a highly altered and mineralized sedimentary sequence, at the margin of the Ell Lake diorite intrusion. The first trenches in the area returned several local grabs of above 1 gram, including 29 grams, whereas results from channel sampling included 37 metres grading 0.81 gram, and 5.2 metres of 2.42 grams.
Last winter, Virginia carried out further IP and standard-frequency horizontal loop electromagnetic surveys over the ice of Ell Lake and conducted an airborne magnetic survey targeting the northern contact between the Ell Lake diorite and the sedimentary sequence. The sediments at the northern edge of the intrusion are an assemblage of sandstone-greywacke conglomerate. These sediments are intruded by dioritic dykes and appear to be affected by east-west-trending folding and faulting. The sedimentary package grades gradually to pegmatite-bearing paragneisses to the north, suggesting a steep metamorphic gradient.
Prospecting and hand stripping initiated at the beginning of the summer resulted in the discovery of the Roberto showing, which delivered 4.29 grams across 12 metres (including 6.16 grams over 5 metres) and 15.8 grams across 3 metres in the first two adjacent channels.
“We quickly realized that this was something special, so we brought in a rig and started to drill late August,” says Archer.
One rig is currently devoted to the Roberto area. Virginia recently added a second rig, which has begun to test some regional IP targets and other metasediment showings. Exploration work to date has outlined gold mineralization over an area in excess of 10 sq. km at the northwestern and northern margins of the Ell Lake intrusion.
The Roberto and Roberto Est zones are hosted in a sedimentary unit strongly altered to sericite, albite, epidote, tourmaline, muscovite and chlorite, presenting an intense potassic alteration. Finely disseminated sulphide mineralization, consisting of less than 5% pyrite, pyrrhotite arsenopyrite and trace chalcopyrite, is developed in the sediments in association with some quartz veining and stockwork. The zones, which strike broadly north-south and dip steeply (80) to the east, are described by Archer as being part of a replacement-style system of en echelon lenses.
“It’s not a typical quartz lens like you would see in Val d’Or [Quebec],” explains Archer. “It’s definitely more the style of Hemlo [in Ontario].”
The gold mineralization in the sandstone-greywacke assemblage has an arsenic-antimony signature associated with silica-potassic-tourmaline alteration. “In this model, the underlying diorite intrusion acts as the source of hydrothermal fluids and/or heat source of a hydrothermal system,” states a recent company technical report. “Some sediment layers may have a chemical or competency contrast that could act as a trap for migrating fluids and lead to precipitation of gold.” The company has noted striking similarities in the alteration found both in the sediments and the diorite intrusion, some 500 metres away.
Fine-grained
Microscopic studies indicate the gold is fine-grained, and a good proportion occurs freely between the microcline and biotite silica grains, says Archer. There is some gold attached to the pyrrhotite and arsenopyrite.
Drilling has been confined by Roberto’s peninsula location, with Ell Lake immediately to the south. The company’s ability to test even the vertical component of Roberto was limited, until quite recently, by swampy conditions off to the east, which impeded the drill rig from stepping back to go deeper. The swamp is now frozen solid and Virginia has backed-up the rig and is drilling deeper holes on Roberto and Roberto Est.
Virginia has completed one line of IP over the Roberto zone, and it’s a good conductor, says Archer. “There are still about two kilometres of strike length that are completely open between the diorite plug and the Roberto area.”
Drilling at lonore is being suspended for the Christmas break and will resume early in the new year, when the ice should be thick enough to begin stepping out on both the southern and northern extensions of the Roberto system.
Several juniors have tied-on to Virginia’s land position in the Opinaca reservoir, including
Sirios acquired, by map staking, two separate projects. Glenn Mullan’s
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