• Title/Summary/Keyword: altered minerals

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A brief review on Oyster shells origin and sedimentary evolution for the formation of limestone

  • Ramakrishna, Chilakala;Thriveni, Thenepalli;Whan, Ahn Ji
    • Journal of Energy Engineering
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    • v.27 no.3
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    • pp.48-56
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    • 2018
  • The shell waste biomineralization process has known a tremendous metamorphosis and also the nanostructure with the identification of matrix proteins in oyster shells. However, proteins are represented in minor shell components and they are the major macromolecules that control biocrystal synthesis. Aragonite and calcite were derived from molluscan shells and evaluated the source of carbonate minerals and it helps for the formation of limestone. The oyster shell wastes are large and massive. The paleoecological study of oyster beds has discovered a near-shore and thin Upper Rudeis formation with storm influence during the accumulation of oysters with highly altered by disarticulation, bioerosion, and encrustation. It is possible even in the Paleozoic mollusks provided sufficient carbonate entirely to the source of microcrystalline of limestone. The present review is to discuss paleoecologically a number of oyster shell beds accumulated and sediment to form the different types of limestone during the Middle Miocene time.

Occurrence types and mineralogical characteristics of asbestos for the Kwangcheon area, Chungnam (충남 광천지역 석면의 산출 유형 및 광물학적 특징)

  • Song, Suckhwan;Hwang, Jung Hwan;Hwang, Byum Goo;Kim, Hyunwook
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.18 no.4
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    • pp.271-281
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    • 2008
  • This study is to characterize the occurrence types and mineralogical characteristics of asbestos for the Kwangcheon areas, Chungnam. The mine areas had been exploited as asbestos mines for several decades since 1930. Host rocks of the asbestos are serpentinites and altered rocks of the ultramafic rocks. Representative samples of the host rocks and minerals were sampled and were examined with microscopes. To confirm for the existences and compositions for the asbestos, the rock samples were analysed with EPMA, XRD and EDS. Chrysotile, tremolite and actinolite were found as asbestos and non-asbestos forms in these areas. Chrysotiles, as non-asbestos forms, occur in the host rocks with mesh and hourglass textures. They, as asbestos forms, are mainly found as the veins. The tremolite and actinolite, as asbestos types, occur as alteration products of the olivine and pyroxene within the host rocks. They, as asbestos types, are also found following the cracks and fractures. Overall results suggest that three types of the asbestos are found in the Kwangcheon and Kaewol mine areas. Based on the occurrence types for the asbestos, additional studies are required for the asbestos in the top soil and air.

Studies on the Skarn-type Ore Deposits and Skarn Minerals in Gyeongnam Province (경남지구(慶南地區)의 스카른형(型) 광상(鑛床)의 성인(成因)과 스카른광물(鑛物)에 관(關)한 연구(硏究))

  • Woo, Young Kyun;Lee, Min Sung;Park, Hee-In
    • Economic and Environmental Geology
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    • v.15 no.1
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    • pp.1-16
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    • 1982
  • Many skarn type iron ore deposits are distributed in Kimhae-Mulgeum area of Gyeongnam Province. Integrated field, mineralogic, geochemical and fluid inclusion studies were undertaken to illustrate the character and origin of the ores in this area. The iron ore deposits in this area are NS or NNE trending fracture filling magnetite veins which are developed in andesitic rocks near the contact with late Cretaceous micrographic granite bodies. Symmetrically zoned skarns are commonly developed in the magnetite veins of this area. Zoning of skarn from center to margin of the vein are as follows; garnet quartz skarn-epidote skarn-epidote orthoclase skarn-altered andesitic rocks. Major ore mineral is magnetite and small amount of hematite, pyrite, pyrrhotite, chalcopyrite and sphalerite are associated. Vein paragenesis reveals four depositional stages; 1) skarn stage, 2) iron sulfide and oxide stage, 3) skarn stage, 4) sulfide stage Minute halite-bearing polyphase inclusions and liquid inclusions are contained in quartz. Filling temperatures range from $257^{\circ}$ to $370^{\circ}C$.

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Metabolic Activity of Desalted Ground Seawater of Jeju in Rat Muscle and Human Liver Cells

  • Kim, Bo-Youn;Lee, Young-Ki;Park, Deok-Bae
    • Fisheries and Aquatic Sciences
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    • v.15 no.1
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    • pp.21-27
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    • 2012
  • Ground seawater in the east area of the volcanic Jeju Island contains abundant minerals. We investigated the metabolic activity of electrodialyzed, desalted ground seawater (EDSW) from Jeju in both cultured cells and animals. The addition of EDSW to the culture medium (up to 20%, v/v) reduced the leakage of lactate dehydrogenase and increased MTT activity in CHO-IR cells. EDSW (10%) promoted insulin-induced glucose consumption in L6 muscle cells as well as the activities of the liver ethanol-metabolizing enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, EDSW suppressed palmitate-induced intracellular fat accumulation in human hepatoma $HepG_2$ cells. Activities of AMP-stimulated protein kinase and acetyl CoA carboxylase, enzymes that modulate fat metabolism, were altered by EDSW in $HepG_2$ cells toward the suppression of intracellular lipid accumulation. EDSW also suppressed hepatic fat accumulation induced by a high-fat diet in mice. Taken together, EDSW showed beneficial metabolic effects, including the enhancement of ethanol metabolism and insulin-induced glucose consumption, and the suppression of intrahepatic fat accumulation.

A Study on Nutritional Characteristics of Common Korean Dietary Fiber Rich Foods (한국인 상용 식이섬유 급원 식품의 영양 생리적 특성)

  • 이선영;오현인
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.2
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    • pp.296-304
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    • 1998
  • The effects of common Korean dietary fiber-rich foods(dried sea mustard, Lentinus edodes and Korean radish leaves) on total gut transit time of diet, serum cholesterol level and mineral apparent absorption ration and tissue level were investigated. Twenty eight male were divided into 4 groups and were fed a control diet(containing 2% cellulose) and three fiber supplementary diet mixed with 10% of the above dietary fiber rich foods for 4 weeks, respectively. Body weight gain and food efficiency ration were not affected by the supplementary diet of fiber but the total gut transit time of diet was shortened in all dietary fiber groups. The Lentinus edodes reduced significantly serum total cholesterol and increased the HDL-cholesterol/total cholesterol ratio at 4th week without and effect on calcium and iron apparent absorptions and tissue levels of the minerals. Radish leaves decreased significantly iron apparent absorption ration with a tendency to increase iron retention in spleen and did not alter serum cholesterol level. Serum cholesterol concentration and calcium and iron apparent absorptions were not significantly altered by the ingestion of sea mustard, while it had more soluble dietary fiber than mushroom and radish leaves.

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Geological Occurrence and Mineralogy of Pyrophyllite Deposits in the Jinhae Area (진해 납석광상의 산상과 광물학적 특성)

  • Kwack, Kyo-Won;Hwang, Jin-Yeon;Oh, Ji-Ho;Yoon, Keun-Taek;Chi, Sei-Jeong
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.2
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    • pp.163-176
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    • 2009
  • The pyrophyllite deposits located in Jinhae area have been studied through field observations and laboratory works including the X-ray diffraction (XRD), X-ray fluorescence (XRF), Electron probe microanalyzer (EPMA) and Inductively Coupled Plasma (ICP). The pyrophyllite deposits consist of mainly illite, dickite, pyrophyllite, diaspore, chlorite, pyrite and copiapite. According to the mineral assemblages, geological occurrences and alteration modes, the altered rocks can be classified into four types: Type A; quartz with silicifictaion, Type B; quartz + illite with illitization, Type C; quartz + dickite + illite with kaolin alteration, Type D; pyrophyllite + illite + dickite + diaspore with pyrophyllite alteraion. Rocks in Type A, which is generated by silicifictaion, have high $SiO_2$ contents more than 90 wt% and distinctive equigranular textures with microcrtstalline quartz. The pyrophyllites from the study area belong to 2M polytype. The host rocks of the pyrophyllite ore in this mine are rhyolitic rock, andecitic tuff and volcanic breccia. The alteration products seem to be controlled by the different lithology of the host rocks. The hydrothermal solution formed the deposits would be inferred to the acidic and have relatively high ionic activity of hydrogen and silica judging from alteration mineral assemblage. Pyrophyllite alteraion zone is generated by highest temperature condition of all alteration zone.

Structural Stability, Weathering and Conservation Method of Granite Standing Sculptured Buddha at Hwangsang-dong, Kumi (구미 황상동 마애여래입상의 구조적 안정성, 풍화 및 보존방안)

  • Lee, Chan Hee;Choi, Suck Won;Suh, Mancheol;Chae, Sang Jeong
    • Journal of Conservation Science
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    • v.9 no.1
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    • pp.21-32
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    • 2000
  • Rock composition of the Hwangsang-dong Granite Standing Sculptured Buddha (Treasure No. 1122) in the Kumi City is biotite-hornblende granodiorite which consists of about 30 pieces of individual rock blocks of same compositions. However, the cap rocks is pebble-bearing coarse sandstone. Rock blocks of the Standing Buddha and surrounding out crops occur well developed several joint systems of $N25^{\circ}$ to $45^{\circ}W$ strike and nearly vertical (70 to $85^{\circ}SE$) dipping. Rock blocks of the Standing Buddha showed vertical, horizontal and oblique joints, and those blocks are well supported by individual blocks. However, the junction part of the blocks are under dangerous situation due 10 seriously mechanical and chemical weathering. Host rock of the Standing Buddha belongs to the HW grade, therefore mostly rock-forming minerals of the granodiorite Standing Buddha altered with clay and iron hydroxide minerals by mineralogical and chemical weathering. Near surface of the Standing Buddha show spore and mycelium of green algaes, and a joint plane alive with weeds. We suggest that if structural stability for the Standing Buddha remove essentially a unstable rock blocks from the main body, and the main body necessitate supporting by rock bolting method because of repeated unstability and minimizing stress to the rock blocks. For the opened joint planes, fractured surface and alive weeds will attempt to fill in a petro-epoxy, petro-filler and biochemical treatments for the algaes, and ground water curtain and wall seems to be necessary for water flow and diminishing humidity of the Standing Buddha.

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Copper Mineralization Around the Ohto Mountain in the Southeastern Part of Euiseong, Gyeongsangbug-Do, Republic of Korea (경북·의성 동남부 오토산 주변의 동광화작용)

  • Lee, Hyon Koo;Kim, Sang Jung;Yun, Hyesu;Song, Young Su;Kim, In-Soo
    • Economic and Environmental Geology
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    • v.26 no.3
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    • pp.311-325
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    • 1993
  • The Ohto and Tohyun copper mine which are located 4 km southeast of Euiseong, Gyeongsangbukdo, Republic of Korea show various common geologic and mineralogic features. Both copper deposits are of hydrothermal-vein types, and associated with fracture system developed during formation of the Geumseong-san caldera in late Cretaceous age. According to structures and mineral assemblages, the mineralization processes have progressed in four stages: three hypogene mineralization stages and one supergene stage. Three hypogene stages are 1) stage I forming $N5{\sim}20^{\circ}E$ veins in the Ohto mine, 2) stage II building $N5^{\circ}W{\sim}N5^{\circ}E$ veins in the Tohyun mine, and 3) stage ill bringing $N80^{\circ}E$ veins which crosscut veins of the stage II. The vein ores consist mainly of pyrite, arsenopyrite, galena and chalcopyrite, minor or trace amounts of magnetite, hematite, pyrrhotite, stannite, bournonite, boulangerite, stibnite, galenobismutite, native bismuth, marcasite, geothite and malachite. The main gangue minerals are quartz and calcite. Wallrock is altered by sericitization, chloritization, pyritization, carbonitization and argillization. Arsenic and copper contents in arsenopyrite increase from stage I to stage III (from 31.28 to 33043 atom.% As) and (from 0.04 to 0040 atom.% Co). Going from stage I to stage III Fe and Mn contents in sphalerite decreases from 12.56 to 0.44 wt.% and from 0.24 to 0.01 wt.%, respectively. The compositional data of arsenopyrite in the early stage I indicate a temperature of $420{\sim}365^{\circ}C$ and sulfur fugacity of $10^{-6.5}{\sim}10^{-8.3}$ atm. Chalcopyrite and pyrrhotite assemblage suggest that Middle stage I was deposited at below $334^{\circ}C$. The compositional data of arsenopyrite in early stage II suggest a temperature range of $425{\sim}390^{\circ}C$ and sulfur fugacity codition of $10^{-6.4}{\sim}10^{-7.3}$ atm. Based on fluid inclusion the Middle stage II was regarded as to be deposited at $420{\sim}337^{\circ}C$ (Chi et al., 1989). Referring composition of sphalerite and stannite middle-late stage II seem to be deposited around $246^{\circ}C$ and $10^{-16.5}$ atm. sulfur fugacity. The ${\delta}^{34}S$ values of sulfide minerals in the Stage I, II, III range from 4.9 to 7.6%0 and indicate igneous ore fluid origin. Based on differences in mineral assemblages, chemical composition and chemical environments of Ohto and Tohyun mine its mineralization are considered to be formed at diffent mineralization ages and by different ore fluids.

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The Nature of Gold Mineralization in the Archean Sunrise Dam Gold Deposit in Western Australia (호주 Sunrise Dam 광상의 금 광화작용)

  • Sung, Yoo-Hyun;Choi, Sang-Hoon
    • Economic and Environmental Geology
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    • v.43 no.5
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    • pp.429-441
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    • 2010
  • The Sunrise Dam gold deposit is located approximately 850 km ENE of Perth, in the eastern part of the Yilgam Craton, Western Australia. The mine has produced approximately 153 t of Au at an average grade of 4.2 g/t, which stands for the most significant gold discoveries during the last decade in Western Australia. The deposit occurs in the Laverton Tectonic Zone corresponding to the corridor of structural complexity in the Laverton greenstone belt, and characterized by tight folding and thrusting. The mine stratigraphy consists of a complexly deformed and altered volcaniclastic and volcanic rocks. These have been overlain by a turbidite sequence containing generally well-sorted siltstones, sandstones and magnetite-rich shales, which are consistently fining upwards. These sequences have been intruded by quartz diorite, ultramafic dikes, and rhyodacite porphyry (Archean), and lamprophyre dikes (Palaeoproterozoic). These rocks constitute the asymmetric NNE-trending Spartan anticline with north-plunging thrust duplication of the BIF unit. The deposit is located on the western limb of this structure. Transported, fluvial-lacustrine and aeolean sediments lie unconformably over the deposit showing significant variation in relief. Gold mineralization occurs intermittently along a NE-trending corridor of ca. 4.5 km length. The 20 currently defined orebodies are centered on a series of parallel, gently-dipping ($\sim30^{\circ}$) and NESW trending shear zones with a thrust-duplex architecture and high-strain characteristics. The paragenetic sequence of the Sunrise Dam deposit can be divided into five hydrothermal stages ($D_1$, $D_2$, $D_3$, $D_4a$, $D_4b$), which are supported by distinctive features of the mineralogical assemblages. Among them, the D4a stage is the dominant episode of Au deposition, followed by the $D_4b$ stage, which is characterized by more diverse ore mineralogy including base metal sulfides, sulfosalts, and telluride minerals. The $D_4a$ stage contains higher proportions of microscopic free gold (48%) than D4b stage (12%), and pyrite is the principal host for native gold (electrum) followed by tetrahedrite-group minerals in both stages.

Limitation of Natural Analogue Studies on Rock Matrix Diffusion (기질내에서의 확산작용에 관한 자연유사연구의 한계)

  • Kim, Chang-Lak;Chang, Ho-Wan
    • Journal of the Korean Society of Groundwater Environment
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    • v.1 no.2
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    • pp.100-104
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    • 1994
  • The rock matrix diffusion provides a retarding mechanism for sorbing and especially non-sorbing radionuclides. It has to be verified not only theoretically and experimentally but also from natural phenomena, before the mechanism can be incorporated fully into transport codes. The natural analogue studies, such as the concentration variation of radionuclides in profiles perpendicular to fluid-conducting fractures and to intrusive contact zones, have been believed to provide a validation. In thermal alteration zones of Naeduckri granite intruded by a pegmatite, large alkali and alkaline earth elements such as K, Rb, Sr, and Ba were moderately migrated during thermal alteration. Li, V. and Nb were also migrated about 9cm in width from the contact between the granite and the pegmatite. The concentration variation of these elements in thermally altered zones seems to be resulted from the local migration due to the re-equilibration among the elements released from the breakdown of primary minerals in the granite. Most of these natural analogue studies simply show only the concentration variation of elements without detailed informations on the diffusion time and other important data fir interpreting the behaviour of radionuclides, because of the absence of appropriate minerals for age data. Despite this problem, natural analogue studies will be needed for transport models of radionuclides in safety assessment.

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