Lefroy Exploration Limited (ASX: LEX) announced that the ongoing 3000m diamond drilling program evaluating the Burns copper gold prospect within the Eastern Lefroy tenement package of the greater Lefroy Gold Project (LGP) in WA has established 55m vertical depth extension and further strong mineralisation.
After the first diamond hole, LEFD004, successfully twinned and extended discovery hole LEFR260, the company had commenced the drilling of second hole, OBURCD025, collared west of LEFD004 to evaluate the host porphyry rocks 55m vertically below the mineralised zones in LEFD004.
LEX reported that the second hole OBURCD025 intersected a 189m downhole interval of the Eastern Porphyry from 179m followed by biotite-chlorite altered basalt to EOH at 396.6m.
The company said that two mineralised zones totalling 57m in length were found – 35m of strong mineralisation from 201m to 236m, including 17m of strong hematite (red rock) altered porphyry with magnetite veining from 219-236m; and a further 22m of strong red rock altered porphyry, with chalcocite, trace chalcopyrite in veins and disseminated pyrite, was found from 269-291m.
The company said that the drilling also established that the Eastern Porphyry is over 100m in true width. Lefory said that the assays from holes LEFD004 and OBURCD025 are expected in late June.
LEX said that the third diamond drill hole in the current 14-hole plan, LEFRD267, is now underway to evaluate the Eastern Porphyry a further 60m vertically beneath hole OBURCD025.
Drilling at Burns copper gold prospect
The company had commenced a 14-hole, 3000m diamond drill program on 20 April 2021 to evaluate the Eastern Porphyry over a 200m strike length on 40m spaced drill sections.
First DD hole LEFD004
LEX had completed the first hole of the program, LEFD004, on 3 May 2020. LEFD004 was designed to twin and extend past the high-grade interval found in discovery hole LEFR260 (38m @ 7.63g/t Au & 0.56% Cu from 134m to 172m) to determine the width of the Eastern Porphyry.
The host Eastern Porphyry was intersected in LEFD004 from 117m to 304.5m, a down hole interval of 187.5m.
Second DD hole OBURCD025
The company has now announced the completion of the second hole of the program, OBURCD025, on 10 May 2021. LEX reported that OBURCD025 was aimed to test the depth extent of the host porphyry approximately 55m below that intersected in LEFD004 and to provide important constraints to the geometry of the mineralisation and the Eastern Porphyry.
Lefroy’s second DD hole OBURCD025 was collared west of LEFD004 to evaluate the host porphyry rocks 55m vertically below the mineralised zones in LEFD004.
LEX announced that a 189m downhole interval of the Eastern Porphyry was intersected from 179m followed by biotite-chlorite altered basalt to EOH at 396.6m.
The company said that two mineralised zones totalling 57m in length were found. The first was 35m of strong mineralisation from 201m to 236m, including 17m of strong hematite (red rock) altered porphyry with magnetite veining from 219-236m. This is the expected position of the high-grade mineralisation in LEFR260
LEX said that a further 22m of strong red rock altered porphyry, with chalcocite, trace chalcopyrite in veins and disseminated pyrite, was found from 269-291m. This is vertically below the 50m mineralised interval, which was newly discovered in LEFD004, so demonstrates vertical continuity of this new zone.
The visual estimate of sulphide mineralisation by type from alteration zones in OBURCD025 is as shown below.
LEX said that observations from hole OBURC025 support the Company’s view that the amount of magnetite-chalcopyrite veining has increased with depth when compared with that observed in LEFD004. This supports the Company’s interpretation that the strength of the Burns Cu-Au mineral system may be increasing with depth.
Third DD hole LEFRD267
The company announced that the next diamond drill hole, LEFRD267, which is the third hole in the current 14-hole plan, is now underway to evaluate the Eastern Porphyry a further 60m vertically beneath hole OBURCD025.
The company said that based on the above interpretation and the encouragement of the observations in hole OBURCD025 it was decided to extend hole LEFR267 to a depth estimated at 440m downhole.
LEX said that the hole is already pre collared to 244m and has an estimated final depth of 440m. This will be the deepest hole yet to be completed at Burns by the Company.
Next steps
The company said that the assays from holes LEFD004 and OBURCD025 are expected in late June. LEX said that the diamond drill program is ongoing. The company said that the drilling is currently being undertaken using one drill rig on a single shift but can be increased to double shift subject to availability of drill crews.
Image Source: Lefroy Exploration Limited
