The Marshall (Lot 2388) and adjoining Sylvester K (Lot 2382) claim (082ESE046) claim are centred near Providence Lake, 1.7 kilometres northwest of Phoenix and 5.8 kilometres northeast of Greenwood. Access is via the Providence Lake road which runs north from the Phoenix mine site.

Between 1967 to 1975, 370 tonnes of ore was shipped from the Marshall claim, yielding 15.2 kilograms of gold, 17.6 kilograms of silver, 0.47 tonne of copper, 2.3 tonnes of lead, and 0.56 tonne of zinc.

The Marshall claim was Crown granted in 1904. Several hand dug trenches and two shafts near the west boundary of the claim are the only remnants from the early years of prospecting. The first major exploration activity was undertaken in 1938 when seven holes comprising 411 metres of diamond drilling and much bulldozer trenching was completed between the two old shafts. The first shipment of ore was in 1967 by leasees from an open cut on the 'San Jucinto zone', 120 metres west of Providence Lake. In 1968 this zone was explored further by 560 metres of diamond drilling and bulldozer trenching. This eventually resulted in the ore shipments. Bulk sample work in 1974 by San Jacinto Explorations Limited, indicated a resource of 45,350 tonne at 17 grams per tonne gold (Northern Miner, October 25, 1979).

The principal rocks underlying the Sylvester K and Marshall claims are sedimentary units of the Triassic Brooklyn Group and offshoot apophyses and dikes of the Lower Jurassic Providence Lake microdiorite stock. The Brooklyn beds are steep, mostly easterly dipping, comprising thick basal sharpstone conglomerates, overlain by a relatively thin transitional argillaceous facies, and a thick upper limestone unit. The Providence Lake microdiorite stock, dated 206 Ma, intrudes the limestone and conglomerate, feeding the somewhat younger volcanic rocks of the Eholt Formation.

Mineralization comprises stratabound massive sulphide in limestone lenses and sulphide disseminations in the accompanying sharpstones and argillaceous rocks of the Brooklyn sequence. The ore mineralogy consists principally of pyrite and smaller amounts of pyrrhotite and marcasite, and traces of chalcopyrite accompanied by carbonates, quartz, and chlorite. The San Jacinto zone has a somewhat broader array of minerals that includes magnetite, specularite, galena, sphalerite, garnet, epidote, and amphibole. The effect of the mineralizing solutions on wallrocks of the ore zone is well displayed in the Sylvester K zone where the footwall argillites have been transformed locally into a fine grained biotite bearing hornfels. Here numerous thin pyrite stringers carry gold and silver values for more than 10 metres distal from the massive sulphide bodies. Elsewhere, chlorite and hematite are common on joints and cracks in the host rocks.

Source of the mineralizing solutions is believed to be the microdiorite stock, although no significant mineralization is visible south of Providence Lake where the main microdiorite body intrudes the Brooklyn limestone. However, considering the wide distribution of microdiorite dikes in the area, it is possible that the principal plutonic body lies at depth.