矿床学试题（Ore deposit examination questions）

矿床学试题（Ore deposit examination questions） 矿床学试题(Ore deposit examination questions) A glossary (a total of 10 points, 2 points for each item) 1, the ore grade, the useful components of ore content. 2, wall rock alteration, refers to the surrounding rock in the ore hydrothermal metasomatism occurred under the action of a series of old mineral was replaced by a more stable mineral of the new. A homogeneous magma body 3, magmatic liquation that under high temperature, when the temperature and pressure drop, separated into melt two or more than two kinds of immiscibility of action. 4, into the original rock formed by metamorphism, deposit refers to the deposit or the original deposit formed by metamorphism with another technology characteristic of deposit. 5, source of ore - forming minerals in sedimentary rock that has been preliminary enrichment and can be activated in epigenetic stage migration out of rock. Two, fill in the blanks (a total of 25 points, each 0.5 points) 1. deposit by the ore body and surrounding rock, ore from ore and gangue, ore from ore and gangue minerals. 2. magmatic deposits knot late magmatic deposits refers to magmatic condensatecrystalline, useful minerals (or mineral) later crystallized from magma enrichment and the formation of the deposit, the main mineral late magmatic deposits is vanadium, titanium, iron ore, its typical structure is sideronitic texture; the main mineral early magmatic deposits is a typical structure of chromium ore is euhedral crystal structure. 3. in the pegmatite deposit, banded structure is the most important and common. The development of banded structure intact, pegmatite rock from the edge to the center, can be divided into the marginal zone and outer zone, middle zone, with several kernel. Pegmatite deposit is an important source of some rare metals and rare earth elements; important mineral areas such as Xinjiang Altai pegmatite deposit. The 4. main components of gas water hydrothermal water, its main source of magmatic water, metamorphic water and groundwater. The five stage 5. skarn deposit formation of two phases, namely skarn period including ____ early (dry) skarn ___, __ late (wet) ___ __ skarn stage and _ oxide ___ stage, including the early period _ (iron sulfide copper sulfide) and ______ __ late stage ___ sulfide (Pb Zn). The 6. porphyry copper deposit alteration zone is well developed, from the inside to the outside is divided into 1 ___ (k) of potassic alteration zone _), 2) __ quartz sericite (like 1000 rock) with ___, 3) _ clay (clay) with propylitization, 4) belt, ore bodies are mainly distributed in __ quartz sericite (like 1000 rock) ___ belt. The 7. metal sulfide deposits in supergene zones from top to bottom can be divided into oxidation zone, __ secondary sulfide enrichment zone and __ primary sulfide ore ________ belt, which can be divided into oxidation zone from top to bottom and completely oxidized subzone (gossan), ___ leaching ________ subzones and ____ secondary enrichment _____ subbelt oxide. Necessary conditions of 8. salt deposit is formed in arid climate and closed or semi closed basin environment. 9. microbes in four main ways to play a role in mineralization, That is _ __ caused the ore-forming elements aggregation, _____ change physical and chemical conditions of the environment, _ _ produce organic acids _______ and __ through the role of the elements of The new supersedes the old. change from one state to another state ________. 10. coal accumulation periods in China mainly include Carboniferous, Permian, Jurassic and third periods. The 11. main factors of metamorphic mineralization is _ temperature, pressure and _ hydrothermal; metamorphic deposits can be divided into three main types, namely contact metamorphic deposits, regional metamorphic deposit and migmatitization deposit. 12., the most famous global giant metallogenic domains are circum Pacific metallogenic domain and paleo Mediterranean Himalaya metallogenic domain (or Tethyan metallogenic domain). Three, choice (a total of 10 points, 1 points for each question, the correct answer fill code in parentheses) 1. mineral resources in China are seriously short of minerals (A) A. chromium, platinum, cobalt, potassium salt, diamond and so on. B., chromium, rare earth, diamond, etc.; C. chromium, platinum, copper, diamond and so on. D., tungsten, lead, zinc and so on 2. according to Carbo Va's stage, skarn type lead zinc deposits formed in (D) stage. A. late skarn; B. oxide; C. early sulfide; D. late sulfide 3. dolomitization is usually related to tungsten and tin minerals. It is the product of alteration (A). A. high temperature hydrothermal solution; B. medium temperature liquid; C. low temperature hydrothermal solution; D. epithermal solution 4., Hunan tin ore deposit is the main output (B) of the deposit. A. tin; B. antimony; C. iron; D. lead zinc 5. Jiangxi Xingzi kaolin deposit belongs to (A) clay deposit. A. residue; B. deposition; C. deposition metamorphism; D. hydrothermal solution 6. alluvial sand deposits have obvious sequence. The main ore bearing layer of placer deposits is (B). A. bedrock layer; B. gravel layer; C. small gravel layer; D. gravel layer and peat layer 7., the Xuan long Lu Jia Bao iron deposit is produced in (A) in the formation of Yu Ling gou. A. Mesoproterozoic: B. Sinian; C. Cambrian; D. Devonian 8. potassium salt is deposited in the late evaporation of brine. Valli Yash C proposed (D) hypotheses to explain the formation of potash deposits. A. said B. said the desert sand;; C. said D. said Saline Lake dry sebkha; 9. the graphite deposit formed by the obvious change of material composition and fabric structure of bituminous coal is called (C). A. sedimentary deposit; B. magmatic deposit; C. becomes ore deposit; D. is metamorphosed ore deposit 10. the Yarlung Zangbo Suture Zone of Tibet belongs to (B) world-class metallogenic domain. A. circum Pacific; B. Tethys; C. Central Asia; D. Central Africa Four, to determine the problem (a total of 10 points, 1 points every day, right "?" said; "'said," wrong and correct) 1. in the process of double metasomatism, SiO2 is transferred from magmatic rock to surrounding rock. (?) The skarn and ore bodies of the 2. contact metasomatic ore deposits are spatially separated. (s) Correct answer: contact metasomatic skarn and ore body can be separated in space, can be stacked. 3. porphyry ore refers to magnetite veins in the ore deposit in porphyrite. (1) Correct answer: porphyry ore refers to continental volcano rocks (porphyrite) related to iron ore deposits. The assimilation of 4. magma refers to some components of surrounding rock, through chemical reactions or directly added to the molten magma in the role of. (1) Correct answer: assimilation refers to the magma in the formation and rise, surrounding rock is melted or dissolved, so that the magma composition change effect. 5. Jiangxi West Huashan useful mineral ores are mainly of scheelite. (1) Correct answer: Jiangxi West Huashan ore minerals are mainly wolframite. 6. mechanical sedimentary differentiation mainly refers to the debris in the handling and deposition process, according to the size, shape, proportion of differences between different. (?) 7. outside Hequ often form placer ore. (1) Correct answer: Hequ inside often form placer ore. 8. diatomite often produced in Cretaceous and Quaternary strata, in the three century. (?) 9. in the colloid chemical sedimentary deposits usually iron ore deposits than manganese deposit form. (1) Correct answer: in the colloid chemical sedimentary deposits usually iron ore deposits than manganese deposit is formed. 10. peat is mainly composed of sapropelic substance transformation and. (1) Correct answer: peat is mainly composed of humic substances and transformation Five, short answer (a total of 25 points, 5 points for each item) 1, the list of metallogenic magmatite exclusive features (5). Answer: 1) and magnesian ultrabasic rocks (such as peridotite) of chromite, copper and nickel output; (1 points) 2) and basic rocks (such as gabbro, Xie Changyan) on the production of vanadium titanium magnetite; (1) 3) and Kimberly rock diamond mine output; (1 points) 4) and alkaline rocks (such as carbonate) on the output of rare earth ore, magnetite etc.; (1) 5) related to granite output of rare metals (Nb, Ta), rare earth ore etc.. (1 points) The characteristics of the 2. gas water filling deposit of hydrothermal ore deposits. Answer: 1) the morphology of ore body is hosted on the host space to the original structure; (1) 2) orebody and surrounding clear boundaries; (1) 3) the composition of ore and rock is obvious differences; (1 points) 4) with unidirectional growth belt, crystal family shape, comb such typical structure; (1) 5) rock alteration is not developed. (1 points) 3. the formation conditions of weathering deposits. Answer: 1) the original rock conditions: with metallogenetic attributes, such as weathering of BASALT LATERITE deposits can be formed of aluminum and nickel; iron rich ultrabasic basic rocks weathering lateritic iron ore deposits can be formed and the nickel deposit; (1 points) Climatic conditions: 2) is one of the most important conditions, such as in the warm tropical subtropical climate area, Conducive to the formation of large aluminum, iron, manganese and other weathering deposits; (1 points); 3) geomorphic conditions: the mountain area and hilly terrain with little elevation difference are most favorable for the formation of weathering deposits; (1 points) 4) hydrological conditions: play a very important role in determining the size and depth of weathered deposits; (1 points) 5) geological structure condition: platform area is favorable for large-scale weathering ore deposit formation. Regional tectonics also plays a controlling role in the formation of weathering deposits, and the base level of erosion determines the final thickness of weathering crust. (1 points) 4., the basic content of "chemical Genesis theory" (Gaja Kopf, 1937) to form phosphorite deposits is briefly described. Answer: 1) the plankton in the photosynthetic zone absorbed the phosphorus in the sea water, making the surface water almost no phosphorus; (1 points) 2) after the death of the organism, it sinks to the bottom of the ocean and takes the phosphorus from the surface water to the deep layer; (1 points) 3) when decreasing, due to the decomposition of organic matter, the CO2 content increases with the increase of the depth, the CO2 partial pressure increases, the capacity of dissolved phosphorus increases, and eventually, the phosphorus water with high CO2 partial pressure is completely decomposed. (1 points) 4) due to the vertical circulation of the sea water, the phosphorus rich and CO2 deep water along the continental slope of the continental shelf zone; (1) 5) because of the shallower depth, the increase of water temperature and the photosynthesis of plants, the partial pressure of CO2 diffusion decreases, which results in the supersaturation of carbonate and phosphate. In the shallow water wave environment, clastic rocks with oolitic and clastic structures can be formed. (1 points) 5. briefly describe the basic characteristics of stratabound deposits. Answer: 1) ore hosting rock series: ore deposits occur in certain stratigraphic horizons and have the characteristics of time control, for example, Nanling lead-zinc deposits are mainly produced in Devonian strata, and are produced in particular lithofacies, often with multi layer mineralization characteristics. (1 points) 2) the source bed: there is a special source bed, the source bed and the reservoir bed (including ore bed), but the same stratum, but also different horizons. (1 points) 3) ore body shape: the ore body is bedded, quasi bedded and lenticular, which is integrated with strata and a few irregular penetrating orebodies, but its mineralization range is still limited to certain stratigraphic horizons. (1 points) 4) ore characteristics: component, sedimentary transformation is relatively simple, transformation and superposition of magma volcano sedimentary composition is relatively complex; which may be residual ore deposition of typical structure, and has the hydrothermal activity obvious signs, such as filling metasomatic recrystallization texture; (1 points) 5) the alteration of surrounding rock: generally, there are alteration of middle and low temperature wall rocks, such as silicification, carbonate, etc.. (1 points) Six, a summary of questions (20 points) 6. The main genetic types (at least four types) and the basic characteristics of various types of iron deposits in China are reviewed, and the examples of ore deposits are given. Answer: 1) late magmatic crystallization differentiation origin (magmatic type) iron deposit Basic features: (1) orebody shape: penetration type: clear boundary between vein and surrounding rock; irregular shape: mainly layered. The ore features: Structure: penetration type is mainly of compact structure, crystal form and aerosiderite structure; shaped by dense disseminated, a massive banded structure. The ore composition is different from that of parent rock. The ore minerals are magnetite, ilmenite and gangue minerals, which are mainly rock forming minerals. Alteration of surrounding rocks: epidote, carbonate, biotite, petrochemical and so on. Examples: Sichuan Panzhihua deposit (or Hebei Temple) of vanadium and titanium magnetite deposit. 2) contact metasomatic origin (skarn type) iron deposit Basic features: 1. Characteristics of ore bodies: the shape is dominated by irregular shape; others are similar to stratiform, nested, vein and so on. The size of ore bodies is mainly small and medium. The main contact zone is near and inclined to the surrounding rock side. The ore composition characteristics: skarn minerals: garnet type (CaAl - CaFe) pyroxene (calcium iron series), hornblende, wollastonite; metal oxide minerals are most common, especially magnetite, hematite, common sulfide: chalcopyrite and sphalerite, galena, pyrite etc.; Ore structure: characterized by coarse-grained structure, various structures formed by metasomatism are very common. Ore structure: massive, disseminated structure, also have banded, geode. (3) alteration of surrounding rock: high temperature alteration occurs in skarn and so on. Low and middle temperature alteration includes silicification, epidote, carbonate, chlorite and so on. Example of deposit: Daye iron deposit in Hubei. 3) continental volcano hydrothermal genesis (porphyrite iron deposit) Basic features: The orebody characteristics: complex geometry shape, breccia and - shaped, bell shaped ring, vein and stratiform etc.; The ore features: disseminated and veinlet disseminated mineralization rock in the middle of the mineral assemblage is albite diopside apatite magnetite assemblage (Tao Linshi); rock top and side (inner contact zone) brecciform and stockwork mineralization of iron mineral assemblage; Yang Qishi (Tou Huishi) - (- apatite magnetite assemblage Washan type); produced in the contact zone of mineralization, ore mass, breccia, quartz and hematite. (Mei Shanshi). The wall rock alteration, wall rock alteration associated with iron mineralization, skarn type early (lower light alteration zone), middle (central dark propylitization alteration zone), late for mud, silicification, carbonatization (or mud paleokarstification), (the upper light alteration zone). Examples of ore deposits: iron deposits in Ning Wu area of China (such as Jiangsu iron ore in Meishan). 4) regional metamorphic genetic iron deposits The basic characteristics of the ore deposit occurs in the region: characteristics of metamorphic rocks, with obvious horizontal zoning mineral (zeolite, greenschist facies, glaucophane schist facies and amphibolite granulite facies, rock facies, eclogite facies); The shape of ore deposits is generally regular, with stratiform and stratiform as the main and large scale; The ore features: palimpsest fabric: palimpsest banded, wrinkles like structure, fine cryptocrystalline structure, palimpsest structure; into fabric: such as flake, Gneissose, taxitic, brecciform, vein and stockwork structure, changing crystal structure, cataclastic structure, embedded crystal structure etc.. Ore composition: the main minerals are magnetite (host), hematite, siderite and so on. Alteration of surrounding rock: usually, the wall rock alteration is strong, and the alteration intensity of the surrounding rock is proportional to the development degree of the rich iron ore body. Common magnesium iron, petrochemical, pomegranate petrochemical, green mud, petrochemical and so on. Examples of ore deposits: Gongchangling iron deposit in Liaoning (Anshan style iron ore) 5) colloidal chemical sedimentary (sedimentary) iron deposits Basic features: 1. Characteristics of the ore body: occurring in the lower part of the transgressive rock series, With the iron mineral zonation (from the shore to the ocean: facies, iron oxide minerals typical minerals are hematite, goethite and limonite; facies, silicate minerals are mainly oolite chlorite facies, carbonate minerals; mainly siderite; facies, sulfide minerals such as pyrite, Marcasite melnikovite, etc.), the orebody is layered, and rock occurrence is consistent; The characteristics of ore ore with oolitic and pisolitic, kidney shaped, banded structure, colloidal structure; The ore is the main component of iron oxide, carbonate minerals, iron silicate and sulfide for The wall rock alteration is not obvious. Deposit example: Hebei pangjiabu iron ore deposits (xuanlong-type iron deposits).