Los Cerros Limited (ASX: LCL) announced that diamond drilling has intersected indications of two separate gold porphyry systems within the Chuscal target of the company’s 100% owned Quinchia Gold Project in Colombia.
The company said that the drillholes CHDDH10, CHDDH11, and CHDDH12 focused on the Chuscal Eastern (Guyacanes) Porphyry Target. LCL said that CHDDH12 intersected porphyritic diorite (assays pending) while CHDDH10 intersected 38m @ 1.14g/t Au from 82m within 94m @ 0.63g/t Au from 82m.
Los Cerros said that drillhole CHDDH13 is expected to commence shortly.
Drilling at Quinchia project
The company had recently commenced diamond drilling and additional porphyry-focussed drilling at the Quinchia project after a maiden program of exploratory drill holes completed last year at Chuscal to aid in porphyry target selection.
Drillhole CHDDH09 had intersected high grade epithermal veins before entering zones of a western (Corporacion) porphyry system. Intercepts included 1.35m @ 10.57g/t Au & 89.77g/t Ag from 133m incl 0.4m @ 94.9 g/t Ag from 133m – epithermal veining; 2.10m @ 37.94g/t Au & 18.64g/t Ag from 232.5m incl 0.8m @ 98.3g/t Au and 44.80g/t Ag from 233.8m – epithermal veining; and 43.70m @ 0.99g/t Au with elevated Cu & Mo from 414m – classic porphyry style alteration and veining.
Hole CHDDH09 was the first occasion that porphyritic diorite, interpreted to be part of the causative porphyry intrusive suite, with associated magmatic breccia, was logged in the western porphyry target.
The company has now announced the updates from drillholes CHDDH10, CHDDH11, and CHDDH12.
Two potential porphyry systems
LCL announced that the recent diamond drilling successfully intersected indications of two separate gold porphyry systems within the expansive Chuscal anomalous footprint.
The company said that the drillholes CHDDH10, CHDDH11, and CHDDH12 focussed on the eastern (Guyacanes) porphyry target. LCL said that the DD hole CHDDH12 intersected porphyritic diorite and assays are pending. The company reported that CHDDH10 intersected 38m @ 1.14g/t Au from 82m within 94m @ 0.63g/t Au from 82m.
Los Cerros said that in addition to this intercept, within a broader ~236m intercept of magmatic breccias is a ~75m magmatic breccia sub zone from 75m downhole with greater density of porphyry vein textures, increased magnetite and elevated gold, and porphyry pathfinders. As a result, DD hole CHDDH11 was commissioned from the same drill pad but oriented to the north-northwest.
Los Cerros reported that a 164m wide zone of magmatic breccia from 211m with classic porphyry pathfinder characteristics – such as pervasive secondary biotite, very high magnetite plus elevated sulphides and vein density was identified. LCL said that of particular interest in terms of gold potential at depth are multiple pulses of diorite adjacent to 164m of magmatic breccia in CHDDH12 with classic porphyry pathfinder characteristics.
Los Cerros said that it was the first occasion that diorite, interpreted to be part of the target causative porphyry intrusive suite, was logged within the eastern target zone, which together with the characteristics of the 164m breccia zone, suggests proximity to porphyry target.
The company said that further work would include additional drilling to systematically test the nature and extent of mineralisation. LCL said that the objective of the drill program is to provide a guide to the mineralization potential of the system, both in terms of potential grade and volume, to guide resource targeted drilling in a third phase drilling program.
LCL said that the next drill hole (CHDDH13) will step 150m further south from pad CHDDH12 and, given the drop in pad elevation, will drill some 200m below the above-mentioned intersections to test for the presence of an underlying causative gold porphyry. The company said that the DD hole CHDDH13 will be targeting the interpreted eastern porphyry under the ‘hot spot’ now defined by five diamond holes (CHDDH01, ‘02, ’10, ’11, and ’12).
Los Cerros Managing Director, Jason Stirbinskis said: “This is a highly encouraging development. Through an iterative approach we believe we are narrowing the area in which we expect to hit the eastern Guyacanes causative porphyry. In-fact, pending receipt of assays from CHDDH12, we might have already hit the porphyry target in CHDDH12.
The developing geological model is not dissimilar to the more advanced Tesorito model in which we see distinguishable pulses of different diorites belonging to the porphyry suite with varying degrees of mineralisation.
There is clearly a zone of significant interest from 318m worthy of follow up defined by porphyritic diorite, magmatic breccias and elevated copper and molybdenum. The deeper zone from 530m with a range of molybdenum grades that are typically associated with mineralised porphyries, could be attributable to the same porphyry source swelling at depth.”
*Image Source: Los Cerros Limited