Meteoric Resources (ASX: MEI) has announced an encouraging update on the company’s deep drilling program to test an interpreted giant Au-Cu rich porphyry system identified in geological, geophysical, and geochemical data immediately below the high-grade Epithermal Juruena Gold Deposit within Brazil’s Alta Floresta Belt.
The company said that the first of three drill deep holes (JUDD042) at Juruena has now reached 500m and is close to intersecting the first major drill target: a large geophysical IP chargeability anomaly interpreted to be associated with a giant Au- Cu rich Porphyry System.
MEI said that an appreciable increase in sulphide content (pyrite) was recorded as having the presence of vein hosted molybdenite and magnetite from 440m downhole.
The company said that JUDD042 is then expected to intersect a second major target: The Au-Cu rich Crentes-Style breccia hosted mineralisation within the Juruena Fault system at approximately 1,000m depth.
The company reported that the final assay results from the 2020 drill program were also received.
2020 drill program assay results
The company reported that the remainder of the assay results from the 2020 drill program were received and will be used in the latest JORC Resource Update due for release shortly.
The company noted that the standout intersection from these assays came from drill hole JUDD039, which intersected the Crentes Epithermal Au-Cu Prospect within a zone of intense hydrothermal brecciation cemented by intense silicification and assayed 51.0m @ 1.40 g/t Au & 0.25% Cu from 118m.
MEI said that three styles of mineralisation occur within the Crentes breccia zone: Weak Brecciation, with best intersection 14.39m @ 2.25g/t Au and 0.55% Cu; Chloritic Brecciation, with best intersection 2.81m @ 18g/t Au, and 0.84% Cu, and 4.64m @ 3.09 g/t Au and 0.29% Cu; and Silicified Brecciation, with best intersection 1.34m @ 1.87g/t Au.
2021 deep drilling program at the Juruena
The company had commenced 2021 deep drilling program at the Juruena project area on the 15th of February with the first of three 1,200m long holes.
Follow-up on IP survey results
MEI said that these three holes were designed to follow up results from the deep IP survey carried out over the region at the end of 2020. This survey was definitive in highlighting Juruena’s potential to contain various major magmatic hydrothermal related Porphyry and Epithermal styles of Au-Cu mineralisation.
The IP survey had returned a large, high chargeability anomaly just below the outcropping high-grade Epithermal Au-Cu deposits, centered at the Uilliam/Mauro Target. The high chargeability anomaly was interpreted to be located approximately 500m below the surface and associated with a potential giant Porphyry Au-Cu target.
Two Au-Cu styles of mineralisation
The integration of both shallow and deep IP surveys with the geology and Au-Cu values obtained in historical drilling identified two Au-Cu styles of mineralisation at the Juruena Project.
The company said that these two targets are the focus for the Deep Drilling Program: Target 1 being the Porphyry Au-Cu target identified in the IP Survey below 500m depth and Target 2 the Crentes-Style Epithermal Au-Cu breccia mineralisation on the Juruena Fault and anticipated to be intersected at approximately 1,000m down hole.
MEI said that based on the latest assay results in JUDD039 (51.0m @ 1.40 g/t Au & 0.25% Cu from 118m), the Target 2 Crentes-Style Epithermal Au-Cu breccia mineralisation at the intersection of the Juruena Fault and IP chargeability anomalies could have the most potential for high-grade Cu-Au mineralisation.
Drilling nearing the tip of Cu-Au porphyry target
The company said that the first of the 3 planned deep drillholes (JUDD042) is currently at 500m and expected to intersect the initial target area in a number of days.
MEI said that JUDD042 is close to intersecting the first major drill target: a large geophysical IP chargeability anomaly interpreted to be associated with a giant Au- Cu rich Porphyry System
The company noted that from 440m downhole, an appreciable increase in sulphide content (pyrite) was recorded as having the presence of vein hosted molybdenite and magnetite, which is common in many porphyry systems.
MEI said that JUDD042 is then expected to intersect a second major target: The Au-Cu rich Crentes-Style breccia hosted mineralisation within the Juruena Fault system at approximately 1,000m depth.
MEI’s Managing Director, Andrew Tunks said, “This is an exciting time for Meteoric with the first deep drill hole just now reaching the top of the interpreted Deep IP anomaly, targeting a potential source for the shallow copper and gold we see at Dona Maria and Crentes.
At this stage of the drilling, we have intersected regional alteration and some pyrite rich zones along with minor molybdenite which is common in the porphyry environment. The hole will continue to test the centre of the IP anomaly and then go on to test the Juruena Fault zone at a depth of around 1,000m. The intercept of 50m @ 1.4 grams per tonne gold and 0.25% Copper is an encouraging indication of the potential of the Juruena fault to be both a host to mineralisation and as a fluid pathway from deeper systems.
Whilst we know there is extensive copper gold mineralisation near surface, imagine if we also strike similar at depth, it would immediately open a further exciting exploration opportunity.”
*Image Source: Meteoric Resources