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Spanish Mountain Gold

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Sediment Hosted Vein Deposits

Recent work on Spanish Mountain recognized that gold mineralization is not only found in quartz veining, but also in shale and siltstone sedimentary rocks. Spanish Mountain has recently been interpreted as a Sediment Hosted Vein Deposit (SHV) by Klipfel, a well-known authority on the subject. SHV deposits are associated with prolific placer gold fields. They usually occur in groups, with one large and associated satellite deposits. They are associated with prolific placer gold fields.

These deposits have typically low grade gold but represent some of the largest deposits in the world. Some possibly comparable examples include Muruntau (60-plus million ounces gold), Natalka (40-plus million ounces gold) and Sukhoy Log (30-plus million ounces gold). Deposits currently mined around the world tend to have similar if not lower grades to those being developed at Spanish Mountain.

Spanish Mountain SHV (from Skygold)

  • One of the first large sediment hosted bulk tonnage gold deposits interpreted in B.C., measuring over 1 sq.km. in size (over 0.5 sq.mi.).
  • Only 20% of the current soil-geochemical and geophysical anomalies has been tested with Diamond Drilling.

Characteristics

According to Klipfel (2005), common features seen in SHV deposits as a group include tectonic setting, host rocks, alteration style, metal content, hydrothermal fluid chemistry, and to some extent, absolute and relative timing of formation.

SHV deposits are hosted in extensive belts of shale and siltsone deposited along the edges of continents known as passive margins. SHV deposits are found in sedimentary belts that have undergone fold-thrust deformation.

SHV are gold-only systems and metallurgically simple, with only minor amounts of other metals (arsenopyrite, stibnite, W, Bi and Te; no or minor Cu, Pb, Zn sulfides). Quartz and quartz-carbonate veins with gold are the hallmark of SHV.

Common alteration includes carbonate and/or sericitic alteration and pyritization of the host rock. Bleaching of the host rock produces pastel colors.

SHV deposits usually occur in rocks of late Proterozoic to early Paleozoic age. Most SHV are mid to late Paleozoic. Some are younger.