The Crescent (L.1711) occurrence is located approximately 2.7 kilometres northeast of the centre of Greenwood at anelevation of 1280 metres. Access is on a side road that connects the Phoenix road to the old railway grade on Montezuma Ridge.
The Greenwood-Grand Forks area contains late Paleozoic and Mesozoic volcanic and sedimentary rocks, mainly in the greenschist facies of regional metamorphism, intruded by Mesozoic plutons and unconformably overlain by Tertiary volcaniclastic and flow rocks. The pre-Tertiary stratiform rocks are contained in a series of five, north-dipping thrust slices with bounding faults, which at many places are marked by layers and lenses of deformed serpentinite. These thrust slices lie above high-grade metamorphic complexes.
The Upper Paleozoic rocks in the Greenwood area are Devonian to Permian Knob Hill Group chert, greenstone and related diorite and serpentinite and Carboniferous to Permian Attwood Group dark-grey argillite, limestone and minor volcanic rocks. They are unconformably overlain by the Brooklyn Formation of clastic sedimentary rocks, limestone and largely submarine pyroclastic breccias and related dioritic intrusions. These rocks probably formed in an environment of growth faulting and explosive volcanism (Open File 1990-25).
The distribution of the Tertiary rocks is controlled by a complicated array of extension faults. Three sets are recognized. The oldest are gently east-dipping, at or near the base of the Tertiary. Later, dominantly west-dipping, listric normal faults have caused rotation so that the Tertiary strata dip to the east at moderate angles; the apparent offset on each of the five of these faults is measured in kilometres. The third and latest faults are north to northeast-trending, steeply dipping, strongly hinged and influenced by the earlier faults.
The hostrocks on the Crescent claim are mostly dark-grey argillite and some conglomerate of the Attwood Group accompanied by a minor amount of serpentinite and ‘old’ diorite.
The mine development consists of a shaft and adit (now mostly collapsed) on a narrow quartz vein. The vein strikes 020 degrees and stands vertically. It consists of 15 centimetres of quartz mineralized with galena, sphalerite (zincblende) and tetrahedrite (grey copper). Near the vein the country rock has the appearance of an iron cap owing to oxidation of original pyrite.
A sample across the vein assayed 8.2 grams per tonne gold, 204 grams per tonne silver and 0.2 per cent lead. The sorted ore reportedly assayed 3806 grams per tonne silver.
In 1985, a sample from a trench located near the southwest border of the Crescent Fraction (L.2462) to the southwest assayed 10.6 grams per tonne silver over 3 metres (Property File - Skylark Resources Ltd. [1985-06-01]: Map - Plan Showing Claims, Geology and Surface Features - Skylark group).
Production from this claim was intermittent from 1905 to 1959, with the greatest tonnage recorded in 1905 and 1908. The total mine output was 250 tonnes yielding 1.90 kilograms of gold; 453.76 kilograms of silver; 3030 kilograms of lead and 3482 kilograms of zinc.
The area has been explored since the early 1900s with at least two shafts and adits being developed, and production starting in 1905. During the 1980s, the area was examined by Skylark Resources Ltd examined the area in conjunction with the nearby Skylark (082ESE011) mine. In the mid-1980s, Rocket Energy Resources examined the area as part of their Greenwood claims project.
