Mantle Thrust Sheet Gem Deposits: The Zabargad Island, Egypt, Peridot Deposits

  • Peter C. Keller


Gemstones formed at great depth; in the earth’s mantle, can be studied and recovered only when this mantle material is brought to the earth’s surface through one of a number of geologic processes. Corundum, such as the rubies from the Chanthaburi-Trat area of Thailand, may be formed in the mantle and brought to the surface as basaltic volcanic eruptions. Diamonds are exclusively brought from great depths in the mantle through unique types of volcanoes known as pipes. Where the earth’s crust thins due to rifting, mantle material, including peridot, may be thrust to the surface in sheets (Fig. 8-1).


Fluid Inclusion East African Rift Mantle Diapir Diabase Dike Early Rift 
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Copyright information

© Van Nostrand Reinhold 1990

Authors and Affiliations

  • Peter C. Keller
    • 1
  1. 1.Natural History Museum of Los Angeles CountyUSA

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