Mining in Manitoba

Secondary Mineral Deposits

 

Primary Mineral Deposits

  • Syngenetic
  • Epigenetic

 

Regional Metamorphism

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Primary deposits through the action of weathering give rise to secondary deposits. Weathering includes both mechanical weathering or the breaking down of rock masses by changes of temperature, the expansion of water as it freezes in cracks, the growth of roots and abrasion from moving solid particles, and chemical weathering caused by the solvent action of surface waters.

These deposits are divided into 3 groups:

1) Sedimentary rocks

These include the plastic sedimentary rocks, such as slate, sandstones and quartzite, formed from the products of mechanical weathering and chemical precipitation. This group includes organic deposits, such as certain iron ores, phosphate deposits, and coal.

2) Secondarily Enriched Deposits

These are formed by the dissolving or leaching of the metal from the upper part of the deposit close to the surface, the metal content of the solutions collecting on the metallic minerals below, forming an enriched zone.

3) Residual and Detrital Deposits

By the removal of soluble material from the original substance the insoluble material remaining may form valuable residual deposits.

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