The Simpson occurrence is situated in the Mitchell Range east of Takla Lake, near the summit of a mountain known locally as Chrome Peak. It comprises occurrences X12-X14 as outlined by Whittaker (Fieldwork 1982-1, Table 1) and is one of numerous small chromite occurrences located in the southern part of the range (see 093N 034, 35, 36, 37, 38, 39, 40). The showing was originally staked by Hunter Simpson and associates in 1941, but no work was recorded and the claims were allowed to lapse.

The Chrome Peak area is underlain by allochthonous serpentinized ultramafics, formerly assigned to the Middle Permian to Late Triassic Trembleur intrusions, and now termed Mississippian to Triassic Oceanic Ultramafites. These rocks host local pre-tectonic orthopyroxenite veins, both pre- and post-tectonic gabbro dikes and "alteration dikes" of albitite-rodingite. The massif is bound by north-northeast and east-trending lineaments and is both surrounded by, and hosts xenoliths of sedimentary rocks assigned to the Carboniferous to Jurassic Cache Creek Complex. Late Triassic-Early Jurassic Topley intrusions have been emplaced into the Cache Creek Complex rocks immediately west and north of the allochthon.

The allochthon comprises widely serpentinized, tectonized harzburgite with minor dunite. The harzburgite is a mottled black-green to black-brown colour on fresh surfaces and is generally intensely foliated. It weathers to a deep brown colour with pale, silvery brown talcose patches. The dunite comprises fine to medium-grained anhedral olivine occurring in contorted, irregularly- shaped patches that reflect the internal deformation of the harzburgite. Xenoliths up to 1 square kilometre in area commonly occur in the southern part of the massif and consist of limestone, dolostone, siltstone with chert laminae and shaly siltstone. Smaller xenoliths occur to the north.

Fine to medium-grained chromite is common as disseminations throughout the ultramafic rocks, varying from trace to two per cent by volume. Harzburgite, however, hosts all but one of the layered and nodular aggregate and massive chromite occurrences in the area, including the Simpson (Fieldwork 1982-1, page 237).

At the Simpson occurrence, numerous small aggregate (greater than 75 per cent) and massive chromite nodules lying parallel to a gently dipping fracture plane are exposed southwest of Chrome Peak. The nodules range from 3 by 8, to 40 by 15 centimetres in area and are believed to have limited vertical extent (Geological Survey of Canada Memoir 252, page 189). Two other aggregate chromite nodules also occur to the north. Much of the chromite was reported to be clean and bright.

Chemical analysis of a composite chip sample collected from all the nodules by C.S. Lord in 1942 gave the following results (Geological Survey of Canada Memoir 252, page 189):

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                 Cr2O3                     45.7 %
                 Cr                        31.3 %
                 Fe                        15.55 %
                 Cr:Fe                     2.01:1
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Work History

Chromite was identified in the area by at least the early 1940s. Little or no other work is reported until at least the 1980s.

In 2004, the area was staked as the IR, PT, PD and OS claims by Ursula G. Mowat and a program of rock and silt sampling and geological mapping was completed. Sampling was reported to be disappointing in that no chromite was located and the rock samples that were analyzed contained no significant values in platinum group elements. Elevated nickel values were encountered in the ultramafics, especially on the IR and PD claims.

In 2009, FPX Nickel Corp. prospected and sampled the area as the Mesa 8-14 claims.