Week 2 - Importance of Minerals PDF

Mineral Resources EARTH SCIENCE MINERAL AS A RESOURCE PRE-DISCUSSION Mineral Occurrence – concentration of a mineral that is of scientific or technical interest Mineral Deposit – mineral occurrence of sufficient size and grade or concentration to enable extraction under the mos...

Mineral Resources EARTH SCIENCE MINERAL AS A RESOURCE PRE-DISCUSSION Mineral Occurrence – concentration of a mineral that is of scientific or technical interest Mineral Deposit – mineral occurrence of sufficient size and grade or concentration to enable extraction under the most favorable conditions Ore – naturally-occurring material from which a mineral or minerals of economic value can be extracted. Ore Deposit – mineral deposit that has been tested and known to be economically profitable to mine. Aggregate – rock or mineral material used as filler in cement, asphalt, plaster, etc; generally used to describe nonmetallic deposits MINERAL DEPOSITS Most rocks of the Earth's crust contain metals and other elements but at very low concentrations There are naturally occurring processes (geologic processes) that can concentrate minerals and elements in rocks of a particular area. TYPES OF MINERAL RESOURCES: METALLIC AND NONMETALLIC Metallic mineral deposits: gold, silver, copper, platinum, iron Non-metallic resources: talc, fluorite, sulfur, sand, gravel OCCURRENCE OF MINERAL RESOURCES The geologic processes involved in the rock cycle play major role in the accumulation and concentration of valuable elements/ minerals. Plate Tectonics: deposits minerals in certain areas. CLASSIFICATION OF ORE MINERALS Magmatic Ore Deposits valuable substances are concentrated within an igneous body through magmatic processes such as crystal fractionation, partial melting and crystal settling. magmatic processes can concentrate the ore minerals that contain valuable substances after accumulating elements that were once widely dispersed and in low concentrations within the magma. CLASSIFICATION OF ORE MINERALS Hydrothermal Ore Deposits concentration of valuable substances by hot aqueous (water-rich) fluids flowing through fractures and pore spaces in rocks hydrothermal solutions - are hot, residual watery fluids derived during the later stages of magma crystallization and may contain large amount of dissolved metals. There are numerous hydrothermal mineral deposits as compared to the different types of deposits: Vein Type, Disseminated, Massive Sulfide, and Stratabound Deposits CLASSIFICATION OF ORE MINERALS Hydrothermal Ore Deposit CLASSIFICATION OF ORE MINERALS Sedimentary Ore Deposits Some valuable substances are concentrated by chemical precipitation coming from lakes or seawater Evaporite Deposits: This type of deposit typically occurs in a closed marine environment where evaporation is greater than water inflow. As most of the water evaporates, the dissolved substances become more concentrated in the residual water and would eventually precipitate. Iron Formation: These deposits are made up of repetitive thin layers of iron-rich chert and several other iron bearing minerals such as hematite and magnetite. CLASSIFICATION OF ORE MINERALS Placer Ore Deposits Deposits formed by the concentration of valuable substances through gravity separation during sedimentary processes. Usually aided by flowing surface waters either in streams or along coastlines. Usually involves heavy minerals that are resistant to transportation and weathering. CLASSIFICATION OF ORE MINERALS Residual Ore Deposits A type of deposit that results from the accumulation of valuable materials through chemical weathering processes. During the process, the volume of the original rock is greatly reduced by leaching. Important factors for the formation of residual deposit include parent rock composition, climate (tropical and sub-tropical: must be favorable for chemical decay) and relief (must not be high to allow accumulation) Common deposits are bauxites and nickeliferous laterites. REFERENCES  Tarbuck, E. Lutgens, and F.Tasa, D., Earth Science: 13th Edition, pp 45 – 47 Carlson, D. H., Plummer, C. C., Hammersley L., Physical Geology Earth Revealed 9thed, 2011, pp564-566 Marshak, S., Essentials of Geology, 4th ed., 2013, pp 379-383 https://www.youtube.com/watch?v=xmXT1YgfoTA. https://mining.cat.com/cda/files/2786351/7/GroundRules- MineralsEverydayLife-15-18.pdf http://www.tulane.edu/~sanelson/eens1110/minresources.htm. http://encyclopedia2.thefreedictionary.com/hydrothermal+solution. http://www.britannica.com/science/hydrothermal-solution. http://earthsci.org/mineral/mindep/depfile/vei_dep.htm. http://geology.com/rocks/pegmatite.shtml. Frank, D., Galloway, J., Assmus, K., The Life Cycle of a Mineral Deposit – A Teacher’s Guide for Hands-On Mineral Education Activities, USGS General Information Product 17, 2005