Abstract

The scheelite ore bodies are enclosed within beds of limestone and skarn, which conformably overly argillite, and dip eastwards into intrusive granite. The resultant contact and trough structure are essential for the formation of persistent ore zones. Faulting is found along the main granite contact and minor faults that strike subparallel to the troughs have exercised a definite structural control. Mineralization arising from deep within the granite was distributed by medium of quartz-tourmaline veins and siliceous veins traversing breccia zones and faults. Tungsten solutions were also concentrated by dikes of granite and pegmatite that cut across the trough.Four distinct types of host-rock are recognized: skarn, limestone, quartz, and greisenized granite. Pyrrhotite and biotite are generally present in the first three types and a close association is shown between scheelite and quartz in all four types. Most of the scheelite is finely disseminated and distinguished only by use of the ultra-violet lamp.The ore bodies are lenticular and tend to thin and splay out on the flanks. They are contact metamorphic in origin. In close proximity to the ore zones the granite is greisenized. The concentration of scheelite in the contact zone is attributed largely to the processes of greisenization. A genetic relationship is inferred between quartz-biotite veins and scheelite.The Emerald and Dodger troughs have each been tested over a length of over 4,000 feet, and the troughs follow the general stratigraphic grain of the country.

First Page Preview

First page PDF preview
You do not currently have access to this article.