The Halfmile-Stratmat integrated project is 100% held by Trevali Mining (Maritimes) Ltd., a 100% owned subsidiary of Trevali Mining Corporation.
On June 30, 2023, Trevali Mining Corporation announced that the Supreme Court of British Columbia granted an order in the Company's ongoing Companies' Creditors Arrangement Act proceedings (the "CCAAProceedings") pursuant to which FTI Consulting Canada Inc., the Court appointed "Monitor", has been granted enhanced powers in the CCAA Proceedings with respect to the Company's business and affairs.
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Summary:
The Halfmile and Stratmat projectss are volcanic massive sulphide (VMS) deposits typical of the Bathurst Mining Camp (BMC). The BMC hosts 45 volcanic-sediment hosted massive sulphide deposits and 95 occurrences, including the world-class Brunswick 12 Mine. BMC deposits formed in a sediment-covered back-arc continental rift during periods when the basin was stratified with a lower anoxic water column. The basin was subsequently intensely deformed and metamorphosed during multiple collisional events related to east-dipping subduction of the basin.
The VMS deposits typically form lenses of polymetallic massive sulphide. Most deposits are zoned vertically and laterally from a high temperature, vent-proximal, copper-polonium bismuth-rich veined and brecciated core to vent-distal zinc-lead-silver-rich hydrothermal sediments. The vent complex is commonly underlain by a highly deformed sulphide stringer zone that extends hundreds of metres beneath deposits and consists of veins and impregnations of sulphides, silicates, and carbonates that cut chloritized and sericitized volcanic and sedimentary rocks.
The Stratmat claims are underlain by a magnetic northeast-southwest trending sequence of predominantly felsic volcanic rocks and lesser sedimentary rocks which are host to all massive sulphide deposits on the property. Provincial Government regional mapping projects have classified the rocks as belonging to the Flat Landing Brook formation of the Middle Ordovician Tetagouche group, which places the deposits stratigraphically above the Nepisiguit Falls formation hosted Heath Steele Minedeposits (Wilson, 1993) located 3 to 5 km to the south. Regional metamorphism is lower greenschist facies.
Coeval foliated gabbro intrusive rocks are common in the eastern half of the property and crosscut and locally assimilate portions of the favourable stratigraphy including parts of the Main Zone. Narrow, magnetic to non-magnetic discordant diabase dykes intrude western portions of the project area, with many aligned parallel to or along east- southeast-trending fault structures. A red to green unfoliated Silurian syenite dyke trends east-southeast, west of the Boundary deposit and cuts stratigraphy at least as far south as the Heath Steele ACD zones. The syenite dyke also displays a magnetic signature. A quartz-feldspar porphyry dyke, reminiscent in many respects of Heath Steele hangingwall (HW) rocks, was intersected in one hole northwest of the Boundary depositt. Distinctive intrusive rock types now number four.
Structurally, the property is highly complex with five periods of deformation being documented in the area (McBride 1976; de Roo et al. 1990; Park 1996). Tectonic thickening and repetition of the mineralized horizon has both enhanced grades and produced mineable widths of ore at the Boundary deposit and N-5 Zones. In cross section, property scale F2 folds manifest themselves as the Boundary antiform, S- 1/North zone synform and the synform/antiform fold repetition of the favourable horizon at depth, below the Boundary open pit. Best grades and widths of economic mineralization at the S-1 deposit tend to occur along the limbs of the major folds, adjacent to the closure areas. The detailed structural study conducted by Adrian Park on the N-5 and Boundary deposits has indicated extremely complex structure on the mine scale. Structures that exist at Boundary/N-5 no doubt persist elsewhere along the Horizon and complicate the rudimentary interpretations of borehole date.
Two consistent fault orientations have been documented. The Stratmat fault trends east-northeast, and overall movement appears to be dextral strike-slip, with a small dip slip component, down to the south (Park 1996). Parallel structures are interpreted at the S-1 deposit and along with Stratmat fault, are believed to be the earliest generation fault structures. A certain periodicity seems to be displayed by these faults.
Periodic east-southeast trending faults are the second and presumably younger orientation observed. Sinistral movement can be implied based upon ground geophysics (magnetics). Locally, these fault zones appear to be intruded by diabase and, west of the Boundary project, by syenite dykes. Although not believed to disrupt stratigraphy, evidence from drilling suggests that a major fault crossing the baseline at approximately 12300E appears to be a pivot or scissor fault because of dip changes immediately east and west of the structure.
The sulphide minerals consist of disseminated and massive pyrite-sphalerite-galena and chalcopyrite. The sulphide minerals are fine- to medium-grained, and are coarser than those typically found in deposits of the BMC.
Disseminated mineralization, commonly of economic grade, occurs in the phyllitic sedimentary rocks as well as in the talc layers which locally grade into massive sulphide. A layer of massive pyrite-chalcopyrite, typically less than 1 m thick, occurs locally on the stratigraphic footwall side of the economic mineralization.
Stratigraphic relationships are based on observations of drill and rock exposures. The copper-rich layer may be in contact with, or grade into pyrite-poor massive sphalerite galena ore that locally is up to a few meters thick (grades average 5 to 15% lead and 15 to 35% zinc). Gangue minerals include muscovite, talc, chlorite, quartz, and carbonates. Many of the copper-rich and lead-zinc-rich massive sulphide layers are separated by talcose or phyllitic zones that commonly carry disseminated sulphide mineralization. Calcite is the most common carbonate, but ferroan dolomite and siderite also are present.