The Rich Rock showing is located in the upper watershed of Rendell Creek, approximately 1.7 kilometres northwest of Lightning Peak.
The showing occurs in a pendant of limestone and volcanic tuff of the Devonian-Triassic Harper Ranch Group which is hosted by diorite and granodiorite of an unnamed Middle Jurassic intrusion.
Mineralization at the showing consists of pyrite, chalcopyrite and possibly arsenopyrite as streaks on fracture faces in a shear zone. A pyritic and siliceous limy tuff forms the hangingwall of the shear; grey-blue coloured limestone forms the footwall. At the south end of this exposure, the limestone has been partly altered to long-fibre wollastonite and garnet. Limonite is common in the shear zone, as are lenses and fracture-coatings of siderite. The limestone bedding dips steeply to the east.
The Lightning Peak area has seen extensive exploration since the early 1900s, with most of the effort directed at the silver-rich, polymetallic veins common in this camp. Trenches exist at the showing which probably date from the 1930s, however no records of their origin exist.
From 1968 to 69, International Mines Services Ltd. carried out geochemical surveys in the general area north of the showing.
From 1984 to 85, Zalmac Mines Limited carried out VLF-EM and IP surveys over portions of the BIG P 1, 2 & 3 claims to the north and northeast of the showing. The 1984 surveys identified 3 polarizable anomalies coincident with east-west VLF-EM conductors. It was speculated that these anomalies may represent mineralized shear zones. In 1985, several east to northeasterly trending VLF-EM conductors were identified in the area. No trenches were dug in this area during the 1985 trenching program, but an old trench was noted to expose a pyritic shear zone, hornfels and skarn.
In 1988, Zalmac Mines Ltd. carried out a trenching program on the showing. Trench 88TR-4A exposed a steeply dipping bed of oxidized sulphides, 25 to 40 centimetres thick. The bed was followed for about 40 metres until soft ground prevented further excavation. A semi-massive to massive zone of sulphides occurs along the contact between the limestone and the meta-volcanics. Sulphides are disseminated in both the hangingwall and footwall of the zone.
A grab sample assayed 6.6 grams per tonne silver and 0.11 per cent copper (Assessment Report 17984). A sample of the semi-massive sulphide zone, collected during a 1991 re-examination of the showing, assayed 0.105 per cent copper and 0.284 per cent tungsten (Assessment Report 22875).
In 2011, Tower Resources optioned the property and completed a program of geological mapping and sampling from outcrops, trenches, and dump piles located near old workings. New areas of precious metal enriched rocks were also identified during this work. The 39 samples, collected over an area of 4 by 1.3 kilometres, average 112 grams per tonne silver and 0.9 gram per tonne gold. A single sample from the showing (VQ) returned 13.6 grams per tonne silver (http://www.towerresourcesltd.com).
