MNE 210 Exam Questions and Answers Rated 100%

MNE 210 Exam Questions and Answers Rated 100% (T/F) Kimberlites are emplaced by a rapid intrusive advance from great depth (up to150 km). Just below the surface, high pressure builds up as the magma encountersground water and degasifies; this pressure builds up until an explosion blows out ofthe surface material. Kimberlite pipes are shaped like carrots. (1pts) - Answers True Name 2 Things that can affect the color of a gem stone - Answers trace element impurities heat special conditions of formations (T/F) The value of gems derives from their unique and strong colors, their rarity(except diamonds), and their ability to be cut into shapes that reflect light. (1pts) - Answers True (T/F) Van der Waals forces are responsible for geckos being able to walk on glass.(1pts) - Answers True What geologic structure is the major source of platinum in South Africa? - Answers Layered Mafic-Ultramafic Intrusions Bushveld Complex What commodity is mined a Banded Iron Formation deposit - Answers Iron What is the leading theory for how BIF's formed - Answers Algoma- from submarine volcanoes Superior-can have, but not necessarily, some volcanic input w/ most or all the ore derived from chemical sediments precipitated from seawater What is the age of most BIF's - Answers 4-.5 Billions Years Ago (T/F) Mississippi Type Deposits are found along the margins of major sedimentary basins within mid-continent areas that have very gentle dips. The ore has been deposited in open spaces in breccias, in enlarged joints and fractures. - Answers True What type of economic minerals would you mine in a MVT deposit - Answers Galena Sphalerite Barite Fluorite Order of Precipitate Minerals. What type of Deposits would contain these minerals? - Answers 1. Calcite 2. Gypsum or Anhydrite (if T and S are higher) 3. Halite 4. Sylvite Evaporites What are the likely host rocks for the mineralization in a MVT deposit - Answers Carbonates Dolomite Jasperoid Breccias Where in the world would you explore for porphyry copper deposits and Why? - Answers Subduction Zones (such as Arizona) That is where they form (T/F) Kimberlites are found from the Precambrian into the Cenozoic period (1,600 to55 Ma) along continental margins - Answers False Found in stable parts of continents Name 2 types of deposits that provide ingredients for fertilizer - Answers Phosphates: Phosphorite Evaporites What physical properties does a mineral hare to have to be found in a placer deposit? - Answers high specific gravity durable not weathered Does a sand and gravel mine have a high intrinsic or high place value, why? - Answers High Place Value Describe the emplacement mechanisms for LMI deposits - Answers Magmatic ore deposits are derived from accumulations of crystals of metallic oxides, or immiscible sulfide, or oxide liquids that formed during the cooling and crystallization of magma With epithermal deposits having such a high grade, why aren't they mined more often or looked at for exploration targets? - Answers Usually to small and complicated to mine economically Malachite - Answers Fizzes, Green, Mamillary CU2 (CO3)(OH)2 Carbonate (T/F) Do copper porphyry's need to have a nipple structure in order to produce an economic deposit? - Answers Often times yes, as ore grade is low, so a large ore body is required to make it economically feasible to mine. What is the principle host rock in red bed copper deposits? What environment are they deposited in? - Answers Ore Shale in the Ocean Can also be hosted by siltstones quartzite and arkose Sandstones These often have ridges and hills which many copper minerals will deposit into (T/F) Bauxites are not weather deposits - Answers False, Bauxites from by weathering clay rocks in tropical climates. Can be formed by alteration as well What is one common mineral where beryllium is found? - Answers Beryl Emerald (Beryl Alteration) Aquamarine Name 4 Major types of Coal - Answers Lignite Anthracite Bituminous Peat If you were going to see a coal deposit being formed today, where would you go? - Answers Swamps and Areas which border water. Aquatic Areas What depositional environment do you find evaporite in? - Answers Marine origin, fresh bodies of water. Anywhere evaporation exceeds precipitation. How do evaporites form? - Answers When evaporation exceeds precipitation. Name one geographic location where you can find borates - Answers Mohave Desert, Boron California, Death Valley