Late Devonian intrusive rocks of the McLymont Plutonic Suite form a large mass bounding the Newmont fault on the southeast. The fault is the southeast bounding fault of the McLymont graben. The Tetra showing occurs about 1 kilometre southeast of the fault.

Host geology to the Tetra showings consists of quartz feldspar porphyry intruding a dioritic, coarse to fine-grained phase forming injection breccias and lobate quartz feldspar bodies.

This area of mineralization occurs at the 1750 metre elevation level on the Kerr 5 claim. Prospecting crews identified a zone of iron carbonate alteration hosting discrete stringers of quartz-barite plus/minus carbonate with varying amounts of tetrahedrite plus chalcopyrite. Veins range from 1 to 30 centimetres in width, and strike between 050 and 070 degrees. A series of mafic dikes, parallel to the veining, display local variation in mineralogy and textures, suggesting multiple dike events. At least one of these dikes was observed to crosscut the veining, suggesting these may be late features. Chalcopyrite and tetrahedrite are the main sulphide minerals, occurring within the veins and in the immediate wall rock. Locally, the veining displays internal brecciation and crustiform textures where the quartz veining is cut by carbonate/iron-carbonate.

The showings host precious metal values up to 18.99 grams per tonne gold and 1093.72 grams per tonne silver; copper up to 1 per cent was obtained (Assessment Report 21006). Veins trend approximately 230 degree and follow a major structure. A proximal association of the veins to a megacrystic quartz-plagioclase porphyry is suggested. Mineralization with corresponding gold and silver values has been intermittently identified for 250 metres of strike length along the structure.

An historic Tetra trench sample graded 13.39 grams per tonne gold, 156 grams per tonne silver 0.75 per cent copper, 0.22 per cent zinc, 20.1 parts per million nickel and 21.6 parts per million cobalt (Sample A0039531, Assessment Report 39128).

Work History

The Kerr 1-4 claims were staked in late October 1987 by Pamicon Developments Ltd who followed up in 1988 with a small assessment work program. No previous work or mineral occurrences were known at the time. A total of 21 man-days were spent prospecting the claims and an additional 32 units were staked. Minimal work was done in 1989 by Pamicon. In 1990, Consolidated Caprock Resources Ltd conducted a prospecting and sampling program, collecting a total of 524 rock chip samples and 269 soil samples on the Kerr 1-6 claims; 14.7 kilometre of ground magnetics and VLF-EM were also completed.

In 2019, Crystal Lake Mining (later changed to Enduro Metals Corporation) collected 2070 rock samples and 6125 hyperspectral measurements were collected throughout the Newmont Lake property. The area was also extensively covered by a property-wide soil sampling program. A total of 2624 soils samples were collected, with a main focus around the Chachi Corridor (including Tetra), Cuba, North/Kerr Glacier, and Thumper areas. In addition to geological and geochemical work, approximately 18 line-kilometres of an Induced Polarization (IP) survey was completed along the northern portion of the west side of the Chachi corridor over known showings that included QS (104B 446), Tetra (104B 448), Chochi (104B 461), Tic 5 (104B 549), Leo (104B 717), Brass Rose (104B 723) and Grey Rose (104B 728).

See Northwest (104B 281) for details of work after the amalgamation of tenures by Romios Gold Resources Inc in the 2000s.