Drilling and assay results from Lavras Gold Corp.’s (TSXV: LGC) LDS Project in southern Brazil confirm that a significant new gold deposit has been found at its Matilde target.
These results come just two months after Lavras Gold announced bonanza gold grades at Zeca Souza and three months after a NI 43-101 compliant resource for the Cerrito Deposit increased the company’s consolidated gold resources to one million ounces.
“We are very gratified with these results from Matilde,” said Michael Durose, Lavras Gold’s President and Chief Executive Officer. “We are seeing long broad zones of continuous intercepts of important gold mineralisation accentuated with multiple narrower higher-grade intervals and in certain instances, bonanza gold grades associated with visible gold.
“Long continuous zones of gold mineralization both laterally and to a vertical depth of more than 480 metres where it is still open, indicate a very strong and large gold system at Matilde.
“Our next steps will be to follow up on these results to test for extensions to gold mineralisation along strike to the west and to the northeast where we are drilling at Matilde Extension.
“Work will also focus on better defining the nature of the structures that host the gold, alteration styles associated with mineralisation, and their relationship to the large three-kilometre-long gold in soil anomaly that is centred on the Matilde target.”
Matilde highlights
Located approximately 4.5 kilometres south of the town of Lavras do Sul, Matilde is one of six priority drilling targets. There are 23 known gold occurrences at LDS. Other drilling targets include Matilde Extension, Caneleira, Vila Marieta, Mato Feio, and Zeca Souza.
Important gold mineralisation occurs in 91% or 30 out of 33 holes totalling 9,847 metres drilled at Matilde to date. This company has received new assay results from 26 drillholes totalling 8,349 metres. Highlights are as follows:
Strike-length continuity
- The structure “bends” to the northwest along the western part of the magnetic anomaly before trending west again. The structure turns to the northeast at the eastern side where it strikes towards the Matilde Extension target about 750 metres away.
- Drilling is currently testing for extensions of gold in both directions at Matilde where mineralised zones remain open.
- Depth and continuity open – Long continuous intervals of gold mineralization occur in holes 20MT-001, 20MT-002, 20MT-008, and 22MT-034.
- Hole 22MT-034 is particularly noteworthy as the hole was drilled 557 metres (approximately 483 metres vertical distance) and bottomed in gold mineralisation. This suggests that Matilde has deep roots, typical of porphyry style mineral systems.
- Zones of gold mineralization are usually associated with green to musky green coloured hydrothermally altered granodiorites consisting of sericite (phengite), quartz and 2-3% disseminated pyrite. These mineral associations are typical of a phyllic style of alteration in porphyry systems.
- However, evidence of potassic alteration is beginning to develop at a depth of approximately 419 metres (drill core interval) in the form of potassium feldspar. This is important, as it is common for the potassic zones of porphyry systems to host higher gold and copper grades.
- Broad continuous zones of moderate gold mineralization accentuated by narrower higher-grade intervals – Long-intervals of gold characterized by zones of moderate grades in the 0.4-0.7 g/t gold range are accentuated by narrower higher-grade intervals typically in the 1-1.5 g/t gold range, but sometimes as high as 2-4 g/t gold. Examples include:
- 20MT-001 – 62.53 metres grading 0.62 g/t gold from 189.70 metres including 12.77 metres grading 0.89 g/t gold from 191.48 metres and 14.00 metres grading 1.13 g/t gold from 228.40 metres
- 20MT-002 – 144.60 metres grading 0.69 g/t gold from 117.00 metres including 27.00 metres grading 1.04 g/t gold from 184.0 metres
- 21MT-008 – 10.00 metres grading 0.88 g/t gold from 83.00 metres including 3.00 metres grading 1.33 g/t gold from 83.00 metres
- 21MT-026 – 28.00 metres grading 1.05 g/t gold from 174 metres including 8.00 metres grading 2.59 g/t gold from 189.00 metres
- 22MT-034 – 19 metres grading 0.67 g/t gold from 56.00 metres including 3.00 metres grading 1.04 g/t gold from 64.00 metres; 29.00 metres grading 0.82 g/t gold from 198.00 metres including 4.00 metres grading 2.57 g/t gold from 203.00 metres; and 2.00 metres grading 4.13 g/t gold from 205.00 metres.
- Bonanza gold grades (more than 10.00 g/t) usually associated with visible gold – At least two different relationships have been observed:
- Cross-cutting (interpreted) lamprophyre dykes suggesting a possible gold precipitation mechanism in at least two areas:
- 20MT-002 yielded 0.60 metres grading 30.90 g/t gold from 261.00 metres. Visible gold specs are observed within an aphanitic glassy matrix of quartz adjacent to a quartz-carbonate veinlet and an interpreted lamprophyre dyke. The lamprophyre dyke appears to have assimilated quartz fragments.
- 22MT-034 returned a zone of 1.00 metres grading 2.84 g/t gold from 407.00 metres. The gold grade seems unusually low given the presence of visible gold and the sample is being re-assayed. Nevertheless, visible gold is observed within an aphanitic matrix of silica (glassy quartz) adjacent to an interpreted lamprophyre dyke that appears to have been silicified. It is possible this interpreted silicified “lamprophyre dyke” is a felsic dyke.
- Visible gold associated with a late-stage centimetre-scale cross-cutting milky quartz veinlet within hydrothermally altered granodiorite.
- 22MT-034 returned 0.66 metres grading 13.10 g/t gold from 419.34 metres. The hydrothermal alteration includes sericite (phengite), chlorite, potassium feldspar, silica, and hematite. Further work focusing on better understanding the nature of these relationships is on-going.
- A northeast-southwest structural trend is emerging – This trend leads directly to the Matilde Extension target about 675 metres to the northeast where drilling is underway. This structure is interpreted to have been intersected in drillholes 21MT-007 and 21MT-009A.
- The geological field team are selecting drill targets to test along this trend. Seven holes have tested the Matilde Extension target, and results will be released once all assay results are received.
- Gold targets associated with structures immediately south of Matilde east-west structural corridor have been identified and require follow-up – These targets are characterised by coincident magnetic low signatures overlying gold in soil anomalies.
Petrographic work confirms gold from Matilde has a magmatic hydrothermal origin
In addition to the drilling programme, Renaud Geological Consulting of London, Ontario, completed petrographic studies on samples from the Matilde target (sample 20MT-002)
The study concludes that “Matilde is a highly altered intrusive rock with primary textures dominantly replaced by hydrothermal alteration. The rock has undergone multiple hydrothermal events dominated by poikilitic growth of hydrothermal quartz and feldspar.
“The rock is dominated by a distinctive green-yellow colour attributed to a groundmass of phengitic micas, chlorite, and albite. The rock appears brecciated and sealed by extremely fine-grained phengitic-paragonitic muscovite, albite, iron-chlorite, and manganese-iron carbonate. Sulphide minerals include pyrite, arsenian pyrite, arsenopyrite, marcasite, silver-bearing tetrahedrite, and electrum. The rock is cross-cut by late-stage anastomosing veinlets of quartz-carbonate.”
These conclusions add to the growing evidence that the gold-bearing fluids that formed gold at Matilde are of a magmatic hydrothermal origin, and that this is primarily a large intrusive hosted gold system with epithermal and porphyry characteristics.
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