Finding Ores

• What does COOG stand for?

  Cut off ore grade
• What is cut off ore grade?


  The minimal grade required in order for a mineral or metal to be economically mined

  -measured in grams per tonne
• Ore


  mineral that contains other, more valuable minerals
• Ore deposits


  a naturally occurring concentration of one or more metallic minerals that can be extracted economically
• IR spectroscopy


  minerals emit different infrared radiation at different wavelengths
• Gravimetry


  Gravimeters detect variations in gravity caused by variations in density and mass. igneous rocks are usually more dense than sedimentary.
• Magnetometry


  Magnetometers detects rocks that are more magnetic
• Seismic surveys


  Echos from controlled explosions or seismic vibrations can give information on depth, density and shape of rock strata
• Rsistivity


  Measurement of the difficulty, with which electricity passes through a material.

  Sedimentary rocks have lower resistivities, than igneous as they have higher water contents
• Trail drilling


  Most expensive per sampling site- is only method that actually produces samples of the rock underground
• Chemical analysis


  Laboratory tests confirm the chemical composition and purity of the minerals in the rock samples.
• Mineral


  a naturally occurring, inorganic substance found in the lithosphere- has economic value
• Remote sensing


  technique that gives information without taking direct samples

  -satellite, aircraft, ground based surveys
• Large scale surveys


  Expensive but most cost effective- low cost per unit
• Geological mapping


  Studying physical aspects and structures of rocks on the earths surface
• Geophysical methods of exploration


  Gravity, Magnetics, Seismic

  -helps detect minerals beneath earths surface
• geochemical techniques


  Testing soils, rocks, water and vegetation for trace of minerals
• Biochemical methods


  Using organisms to find anomalies in the content of elements
• Interpretation of data


  used to determine location, size, orientation and value of the prospective mineral deposit