The map covers the McKinney Creek area, to the north of Bridesville, between Rock Creek and Baldy Mountain and bordering
on OF 2007-7. It further expands westwards, studies of the pre-Tertiary rocks by Fyles in the Greenwood area (1990). The
area is underlain predominantly by Paleozoic rocks belonging to the Anarchist Schist. These comprise a meta-sedimentary
unit of quartzite (meta-chert), argillaceous quartzite, quartz-chlorite and quartz-biotite schists with
minor metabasalt and limestone, and a meta-volcanic unit of massive greenstone flows with minor
breccias and tuffs and minor meta-sediments. The general map pattern of the metasedimentary and
metavolcanic units seems to define a major northwesterly trending fold. However, the lack of conclusive way-up structures
and stratigraphic relationship precludes determining if the fold is antiformal or synformal.
Intrusive rocks rim the McKinney Creek area on north, west and south
sides. Jurassic intrusions comprise two major bodies – the McKinney Creek and Mount Baldy granodiorites as well as an
unnamed suite of ultramafic and mafic intrusions. The granodiorites have been correlated with the mid-Jurassic Nelson
Intrusions, though geochronological data is lacking. The mafic rocks may be an older phase of the Nelson suite and are
both intruded by granodiorite as well as included as xenoliths in granodiorite. The north-eastern margin of the map area
is marked by a white to pinkish K-spar megacrystic granite intrusion typical of the Coryell Suite. Tertiary-age porphyry
dykes abound through the area intruding all older lithologies.
Gold veins of the Camp McKinney camp and the surrounding area are hosted
in the Anarchist Schist but are believed to be genetically related to Tertiary intrusions. The band of ?Jurassic mafic
and ultramafic intrusions is related to those seen to the southwest of the map sheet (e.g. the Old Nick) and similarly
bear chromite and magnetite mineralization, as well as talc and soapstone.
