お知らせ • Feb 02
Tristar Gold - Castelo De Sonhos Drilling Succeeds on Two Fronts
TriStar Gold Inc. announced results from 18 holes (2,645m) completed in November of last year at the Castelo de Sonhos gold project ("CDS"). There are two drilling programs currently underway at CDS. New infill holes are designed to improve confidence in resource estimates, while new holes in open extensions beyond the preliminary pits defined by the PEA (September 17th, 2018 press release entitled "35% increase in resources at Castelo de Sonhos as preliminary economic assessment begins") are designed add to resources. Geological reasoning, combined with artificial intelligence, has been used to develop targets for significant gold mineralization that may lie below the reach of an open pit project. New holes in these areas will investigate the geology and grade to improve TriStar's understanding of the potential for underground mining at CDS. The best results from exploration upside holes lie south of a granite outcrop in the center of the plateau, where CSH-20-498 encountered carbonate minerals not previously encountered in shallower drilling, along with abundant fuchsite; the highest grade in this hole was 4.5 g/t over 0.6m, near the bottom of the hole where it approached the granite. The drilling in the north of Esperança South continues to show that significant gold mineralization is open down dip, to the west, and along strike, to the north and northwest into the valley. Once drilling in this area reaches the required spacing, there will be considerable potential for converting Inferred resources to Indicated resources, and for broadening the footprint of Inferred resources. Drilling in mid-Esperança South has returned broader low-grade intersections that will be used in the mineral resource update, and that will enable the definition of additional low-grade Indicated resources. Drilling on one of the open down-dip extensions at Esperança East shows that gold mineralization continues down-dip to the west, in the same manner as seen elsewhere on the plateau. In the Fall of 2020, TriStar began systematically collecting multielement chemistry data from every hole; artificial intelligence and machine learning studies coordinated by GoldSpot Discoveries Inc. ("GoldSpot") have demonstrated that multielement data is of great value in building detailed models of stratigraphy and structure. GoldSpot will soon extend their cluster analysis to Esperança East, where the folding and faulting are more complex, and where detailed models of stratigraphy and structure will be essential for
feasibility study resource models. TriStar geologists have recognized the potential for higher-grade bands to exist at depth, where granitic intrusions may have provided a heat source and fluids for taking paleo-placer gold in to solution, moving it slightly, precipitating and possibly concentrating it in a new location outwards and ahead of the intrusion. The investigation of this possibility has begun with a detailed 3D model of the granites and the
mineralized conglomerate band at depth. The hole that provides the greatest insights into the possibility of remobilized gold is the diamond drill hole of the four exploration upside holes, CSH-20-489, which was collared in the sediments south of a granite outcrop, and angled toward the intrusion. This hole contained abundant fuchsite, a mineral not commonly observed in shallower holes, and also contained the project's first confirmed carbonate
minerals. Both of these observations show that the nearby granite has heated the surrounding rock and injected hydrothermal fluids for a few hundred meters outwards. The 4.5 g/t interval toward the bottom of
the hole is a promising indication, but only one sample. As shown on Figure 1, additional deep holes are being drilled to the east and north of the same intrusion, approach it from two other sides. Once the
geological observations from all three holes are available, along with the gold assays and multielement chemistry, TriStar geologists will be able to review and refine their understanding of the potential for deep mineralization in the center of the plateau. Three near-surface RC holes in the exploration upside program have returned assay results. One of these, in Esperança East, had to be abandoned prior to reach its target depth. The other two, near a
granite on the footwall side of the main conglomerate band in Esperança South, did encounter low-grade gold mineralization near surface. A more complete understanding why this area supported a large
artisanal operation will be possible when two additional near-surface holes are drilled on the north side.
