District Metals Corp. (TSX-V:DMX) has reported assay results for the remaining 11 drill holes from the Phase II drill program at its high-grade polymetallic Tomtebo property located in the Bergslagen mining district in south-central Sweden.
The company said a total of 4,906 metres (m) in the drill holes was completed during the program that was carried out from October to December 2021.
District noted that three holes - TOM21-027, -028 and -032 - targeted the Steffenburgs zone as a follow-up from hole TOM21-025, which returned 14.3m at 14.2% zinc equivalent (ZnEq) from 210 to 224.3m. Hole TOM21-028 was drilled 60m up plunge from TOM21-025 and intersected the longest interval of continuous strong sulphide mineralization at Tomtebo to date.
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Hole TOM21-027 was drilled approximately 80m down plunge from hole TOM21-025 and encountered stringer and vein sulphide mineralization along the northwest edge of the massive sulphide lens at the Steffenburgs zone. Hole TOM21-032 was drilled approximately 35m northwest from hole TOM21-025 and also encountered stringer and vein sulphide mineralization.
From late January to early February 2022, District said borehole electromagnetic (BHEM) surveys were conducted, and interpretations are underway. At the Steffenburgs zone, the interpreted BHEM results will assist in delineating the massive sulphide lens to optimize drill targeting at depth.
"The new massive sulphide intersection in hole TOM21-028 provides another excellent intersection in the Steffenburgs zone massive sulphide lens,” District technical advisor Rodney Allen said in a statement. "This intersection shows a zonation from intense "stringer" sulphide veining in the stratigraphic footwall, followed by a thick interval of massive sulphide, which is in turn overlain by relatively weakly mineralized hanging-wall rocks.
Allen said the massive sulphide interval also shows zoning, comprising a core of massive pyrite with relatively minor sphalerite, enclosed by massive pyritic sulphide with numerous prominent bands of rich sphalerite-galena.
“These zoning relationships are common in high-grade VMS deposits; they indicate that the massive sulphide grew progressively and evolved with time,” he added.
The company said high-temperature solutions welled up in the footwall stringer zone, dissolving zinc-lead-silver-gold from the footwall side of the deposit, leaving a massive pyritic "residue" in the lower to central parts of the massive sulphide lens and concentrating the metals in the upper and lateral parts of the lens.
“These relationships provide further confirmation that we have intersected classic VMS (Volcanogenic Massive Sulphide) mineralization on a major VMS ore horizon,” Allen said.
Additionally, District said in several places, sphalerite-galena bands in the massive sulphide can be seen to form tight folds, providing further evidence that the Steffenburgs zone massive sulphide is deformed and may be folded also on the larger scale.
“We now have a number of good intersections of both massive sulphide and stringer sulphide in several drill holes and because the mineralization is likely folded it is not yet entirely certain how the various intersections join up from drill hole to drill hole,” Allen continued. “We anticipate that data from recent geophysical surveys and lithogeochemical analysis of drill core samples, combined with the geological mapping of the drill cores will enable us to better understand the geometry of the mineralization and to plan the best locations for additional drill holes."
Highlights from the drilling include:
- TOM21-028 intersected 30.05m at 10.9% ZnEq (148.35 to 178.40m), including 21.8m at 14.3% ZnEq (152 to 173.8m), including 10.05m at 17% ZnEq(157.15 to 167.2m)
- TOM21-032 intersected 6.80m at 2.5% ZnEq (149.2 to 156 m) and 12.7m at 3.3% ZnEq (221.3 to 234m)
- TOM21-027 intersected 3.5m at 4.7% ZnEq (61.4 to 64.9 m), 8m at 2% ZnEq (229 to 237m), and 2.7m at 7.2% ZnEq (274.4 to 277.1m)
"The Steffenburgs zone is showing great promise that is most recently highlighted with a wide intercept of strong polymetallic mineralization in hole TOM21-028 that has returned 30m at 10.9% ZnEq,” District CEO Garrett Ainsworth added.“Elevated gold values were observed above and below the massive sulphide intercept in hole TOM21-028, which supports the occurrence of successive mineralizing events that opens up additional targets at Tomtebo.”
Ainsworth said assay results from hole TOM21-027 show that the polymetallic mineralization at the Steffenburgs zone remains open, and it appears that this hole clipped the northwest outside edge of the plunging massive sulphide lenses encountered by holes TOM21-001, -025, and -028.
“Our next phase of drilling at Tomtebo is planned for early April and will focus on the Steffenburgs zone where targeting will be finalized based on the BHEM and whole-rock geochemistry interpretations," he concluded.
The Tomtebo project in the Bergslagen mining district of Sweden is District's main exploration focus.
Tomtebo comprises 5,144 hectares and sits between the historic Falun mine and Boliden's Garpenberg mine, which are 25 kilometres (km) to the northwest and southeast, respectively.
Two historic polymetallic mines and numerous polymetallic showings are located on the Tomtebo Property along an approximate 17 km trend that exhibits similar geology, structure, alteration and VMS/SedEx style mineralization as other significant mines within the district.
Contact the author at stephen.gunnion@proactiveinvestors.com