Examples

• Main Authors: Karen D. Kelley, Robert R. Seal, Jeanine M. Schmidt, Donald B. Hoover, Douglas P. Klein, Red Dog, Rammelsberg (germany) Faro
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Sullivan; Yukon; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.693.6542; http://pubs.usgs.gov/of/1995/ofr-95-0831/CHAP29.pdf

Deposit geology Lens-like bodies of stratiform sulfide minerals (lead, zinc, ± iron) as much as a few tens of meters in thickness are interbedded with fine-grained dark clastic and chemical sedimentary rocks. These deposits may have large lateral extent (hundreds of meters to kilometers). Mineralized rock varies from a single layer to numerous bodies that may be vertically stacked or lateral equivalents. The most common associated sulfate mineral is barite which may be peripheral to or stratigraphically above the deposit (Rammelsberg and Meggen, Germany; Tom, Yukon Territory; Lady Loretta, Australia; and Red Dog, Alaska), or it may form crudely segregated mixtures with sulfide minerals (Cirque, British Columbia). Many deposits have no associated barite (HYC, Australia; Sullivan, British Columbia; and Howard's Pass, Yukon Territory). Stockwork, disseminated, or vein-type ore, interpreted as feeder zones to stratiform mineralized rock, are sometimes found underlying or adjacent to stratiform ore and are sometimes accompanied by alteration of footwall rocks (fig. 1). U.S. Bureau of Mines (1993) statistics show that in 1993 the two mines in the United States with greatest zinc output were Red Dog, Alaska and Balmat, N.Y. In 1994, the Red Dog mine produced 533,500 t of zinc concentrate with an average grade of 55.8 weight percent zinc (Mining Journal, 1995). Mines in the Balmat district produced 499,000 t in 1993. Both mines also produce lead and silver.