Geology of Canadian Mineral Deposit Types
This volume defines and summarizes in a comprehensive and systematic manner the essential characteristics of all economically significant types of Canadian mineral deposits. These summaries reflect the current understanding of mineral deposits and correspond closely to the definition of mineral-deposit types in common use. A large color section serves to illustrate details of some of these mineral deposits, and locations of all known deposits are presented on an oversize figure and are indexed in an appendix, as well. Like previous volumes of this type, this volume will be a long-standing premier reference for academia, industry, and government institutions alike.
Abstract
Vein-stockwork deposits of tin and tungsten occur in a wide variety of structural styles that include individual veins, multiple vein systems, vein and fracture stockworks, breccias, and replacement zones in altered wall rocks adjacent to veins. The deposits generally occur in or near granitic intrusions which have been emplaced at relatively shallow levels (1 to 4 km) in the Earth’s crust. The associated intrusions are highly fractionated and typically enriched in lithophile elements such as Rb, Li, Be, Sn, W, Mo, Ta, Nb, U, Th, and REEs, and volatile elements such as F and B.
Hydrothermal alteration of wall rocks associated with vein-stockwork tin and tungsten deposits is commonly greisen-type alteration that is characterized by Li-, F-, and/or B-bearing minerals such as topaz, fluorite, tourmaline, and various F- and/or Li-rich micas. Vein-stockwork deposits with extensively greisenized wall rocks that contain disseminated tin and/or tungsten minerals have been referred to as “greisen” deposits (Shcherba, 1970; Taylor, 1979; Reed, 1986). Such deposits are included in this review as vein-stockwork deposits; “greisen” is used primarily in reference to a type of alteration rather than as a type of deposit.