The showings are on Cornwall Creek, about 5 kilometres upstream from Ashcroft Manor (ca. 1939) and about 6.5 kilometres west of Ashcroft. The workings and exposures are spread along the northeast wall of the creek for several hundred metres.

The hostrock for the chromite prospect is projected to be serpentinite of the eastern facies of the Carboniferous to Jurassic Cache Creek Complex. This consists of a Late Triassic accretionary prism/subduction complex associated with the Nicola volcanic arc. The melange contains Pennsylvanian and Early Permian limestones, chert, basalt, argillite and ultramafic rocks in a matrix of Permo-Triassic chert and argillite.

At Cornwall Creek, two large bodies of serpentinite abut greenstones, ribbon cherts and limestone. The greenstone consists of fragmental debris flows and lesser amounts of massive vesicular flow rocks. The ribbon chert is highly contorted with layering of up to several centimetres. Some thin argillite lenses are interbedded with the chert. Limestone is generally white, massive and recrystallized.

The serpentinite is massive and well fractured to sheared. Contacts with the surrounding rocks have not been described. The serpentinite contains abundant bastite, relict pyroxene and olivine, indicating harzburgite as the protolith. Chromite mineralization consists of disseminated grains in serpentinite. A sample from the best disseminated material from a dump of an opencut, presumably representing a pod intersected in the opencut, assayed 0.3 per cent Cr2O3 (Stevenson, 1941).

The original claims, the Chrome Ore 1-4 and 11-14, were staked in 1938 for the Calgary Mineral Syndicate; the Chrome Ore claim was staked by Lester Starnes of Ashcroft. In 1939, some exploratory work was carried out by the Syndicate with J.O. Williams of Ashcroft in charge. This work consisted of eight opencuts that exposed serpentinite, some minor chromite mineralization and adjacent sediments. One adit was driven into the bank at 080 degrees for 16 metres with a 10-metre opencut approach. This working exposed sheared serpentinite and a major fault zone trending 075 degrees and dipping 70 degrees south (Stevenson, 1941). The original claims were allowed to lapse and the showings were restaked (3 claims?) by T. Blakiston-Gray of Lytton and his associates, but no work was reported.