D 15 to 55 for most deposits are consistent with a fluid in isotopic. These ore indicators have districtwide and more local sig. Magmatic and metamorphic ore deposits skarn deposits. This partly explains the high level of controversy on the origin of some. Magmatic and metamorphic ore deposits introduction. Contact metasomatism contact metasomatism is a process of formation of new mineral by reaction between the contact rock and the escaping high temperature gaseous emanation with other important materials from the magma chamber. Pdf magmatic and metamorphic ore depositsskarn deposits. Metamorphogenic deposits article about metamorphogenic. Structural deformation may alter the form and attitude of some of these deposits. Deposits are typically found in shales, cherts, limestone, dolomites and sandstone as well as hydrothermal veins or as chemically dissolved phosphate minerals in igneous and metamorphic rocks. Magmatic and metamorphic ore depositsmetamorphic ore forming environments.
The types of metals in the deposit depend on the magma. Lode and veinstyle gold deposits are a distinct class of hydrothermal ore deposit. Exploring for and assessing ore deposits in metamorphic terranes are facilitated by the recognition of a range of lithologicmineralogic guides that result from metamor phism of preexisting ores and their associated host rocks. In some occurrences, minerals can be extracted at a profit by mining. Igneous, metamorphic, and sedimentary ore deposits fig 1, a, b einaudi, 2000,stated that all mineral deposits can be classified into three types based on process, namely magmatic deposits, hydrothermal deposits, and surfacial deposits formed by surface and groundwater.
The authors comprehensively describe the physical and chemical characteristics of ore deposits, and correlate them with environments and conditions of deposition since ore deposits are best interpreted as extensions of the environments responsible for their enclosing rocks. If youve been searching for a modern textbook on metallic ore deposits, this is a good. Geology and ore deposits of the shafter mining district, presidio county, texas by clyde p. Examples of concentrating and transporting agents are groundwater, seawater, and magma. The role of fluids in syntectonic mass transport, and the localization of metamorphic veintype ore deposits. Chapter d gold deposits in metamorphic rockspart i gold in the united verde massive sulfide deposit, jerome, arizona by ed dewitt and jerome waegli the alaskajuneau and treadwell lode gold systems, southeastern alaska by thomas d. One of the worlds largest phosphate deposit is the phosphoria formation, located in southeast idaho. Ore deposits are classified based on how they form, whether as a result of an igneous, metamorphic, or sedimentary process, or a hydrothermal exposure process.
Ore deposits contact metamorphism linkedin slideshare. Within these three broad modes of origin, a mineral deposit of economic value might have originated due to set of simple or complex processes. Metamorphic fluids and their relationship to the formation. Richen zhong, wenbo li, yanjing chen and hongliang huo, oreforming conditions and genesis of the huogeqi cupbznfe deposit in the northern margin of the north china craton.
Mineral deposit formation of mineral deposits britannica. Metamorphosed deposits form as a result of the processes of regional and local metamorphism of minerals. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Metallic ore deposits can form wherever there is igneous activity, due to either vulcanism or plutonism. Ore deposits formed by lateral secretion are formed by metamorphic reactions during shearing, which liberate mineral constituents such as quartz, sulfides, gold, carbonates, and oxides from deforming rocks, and focus these constituents into zones of reduced pressure or dilation such as faults. Introduction ore deposits are crustal concentrations of useful elements that can be exploited at a pro. Pdf economic geology metamorphic ore deposits researchgate. Pdf magmatic and metamorphic ore depositsintroduction nima.
Surficial uranium deposits report of the working group on uranium geology, iaeatecdoc322, 1985. The deposits are subdivided into metamorphosed and metamorphic deposits. Valuable nonmetallic mineral deposits are formed from rocks chiefly by the crystallization and. As a consequence, a general role in gold deposition for fluid mixing, temperature decrease andor fluid pressure decrease and boiling is unlikely, although such effects. Metamorphosed and metamorphogenic ore deposits contents ores and metamorphism. Magmatic and metamorphic ore deposits porphyry deposits. Examples and illustrations emphasize structural, chemical, and temporal. Mcqueen crc leme, australian national university, canberra, act 0200 and school of rehs, university of canberra, act 2601. Principles of igneous and metamorphic petrology anthony philpotts. Some deposits are related to metamorphic processes and are as such classified as deposits of metamorphic origin. The chief agencies involved are heat, pressure, time, and various solutions. Metamorphic and metamorphosed ore deposits metamorphic ore deposits is a class that owes its economic interest to largely isochemical metamorphic re equilibration and recrystallization of preexisting material which had no use in. Goldrich deposits can be formed at all stages of orogen evolution, so that evolving metamorphic belts contain diverse gold deposit types that may be juxtaposed or overprint each other. Many hydrothermal ore deposits are hosted by metamorphic rocks, and so the possibility that ore deposits may form from metamorphic fluids.
Asbestos minerals were once used in a wide variety of products. For example, slate and marble are building materials, garnets are used as gemstones. Asbestos minerals were once used in a wide variety of. Gilligan editors, mechanical and chemical remobilization of metalliferous mineralization. The role of metamorphic fluids in the formation of ore deposits. Metamorphogenic deposits mineral deposits formed in the process of metamorphism under conditions of high pressure and temperature. Pdf mineral deposits ore deposit environments formation of mineral deposits introduction the hydrologic cycle the rock cycle types of sedimentary.
The correlation of major gold deposits with rock type, even when the gold is primarily in veins, argues for rock. Metamorphosed shales and graywackes, which make up much of the sedimentary component of the upper crust, initially contain. Mineral deposits formed as a consequence of sedimentary processes. The terms metamorphosed, metamorphic, and metamorphogenic as applied to ores are also considered.
Vein mineral deposits includes a considerable variety of ore deposits formed under various conditions by the concentration of the ore from the molten rock in process of cooling, and its subsequent deposition in fissures and joints, crevices, and pores. Mineral resources of igneous and metamorphic origin. Only students with a semestermodule mark of more than 50% and an exam mark of more than 35% will be. The role of fluids in syntectonic mass transport, and the. Mineralization in the contact metamorphic ore deposits of the. The contact metamorphic ore deposits in the environs. Metamorphic belts are complex regions where accretion or collision has added to, or thickened, continental crust. Lenticular masses, veins, lodes and zones of disseminated mineralization result from metamorphic processes. The most common is silica, which forms a number of materials, including silica sand, sand and gravel, and flint. Students who gain less than 40% in the exam will be considered to have failed the course, irrespective of the semestermodule mark. Metasomatic and metamorphic talc and magnesite deposits may also be important sources of these. Pdf economic geology metamorphic ore deposits find, read and cite all the research you need on researchgate. The metallic ore deposits can be found near sites of recent igneous activity or activity that happened sometime during the geologic past.
Hydrothermal mineral deposits, springerverlag, berlin. Knowledge of metamorphic processes and rocks is valuable, because metamorphic minerals and rocks have economic value. Magmatic and metamorphic ore depositsporphyry deposits. Relating to the rocks, ore deposits, and springs produced by hot water or magma. Petrology of ore deposits university of south alabama. Chapter 3 metamorphic rocks study guide by juliejeffrey includes 33 questions covering vocabulary, terms and more. This may occur without much hydrothermal fluid flow. They eventually create richmetallic fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals. As an example of early classification of hydrothermal ore deposits, here is enclosed lindgrens evans, 1993 classification based on approximate t empe ra t ure s of f orm at ion. Table of contents pdf society of economic geologists. Hydrothermal mineral deposits are accumulations of valuable minerals which formed from hot waters circulating in earths crust through fractures. Ore deposits formed by metamorphism metamorphic processes profoundly alter preexisting mineral deposits and form new ones.
Gold deposits in metamorphic rocks of alaska mineral. Recognition of the environment and existence of potentially economic mineral deposits may be based upon a. An ore deposit may be either of igneous or of sedimentary origin. Hypot her mal 300 600 ec, mes o t h er mal 200 300 ec. Pdf magmatic and metamorphic ore depositsmetamorphic.
Pdf magmatic and metamorphic ore depositsintroduction. Volcanic deposits surficial deposits metasomatite deposits metamorphic deposits lignite black shale deposits other types of deposits literature. Ross abstract the shafter mining district is principally notable for the presidio mine, which. The materials acted upon are either earlier formed mineral deposits or rocks. Mineral deposits form because some medium serves as a concentrating and transporting agent for the ore minerals, and some process subsequently causes the transporting agent to precipitate, or deposit, the minerals. Sedimentary deposits are formed through the erosion, transportation, and redeposition of minerals that can survive the rigors of transportation.
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