• Title/Summary/Keyword: hydrothermal quartz

Search Result 264, Processing Time 0.022 seconds

Au-Ag Minerals and Geneses of Weolyu Gold-Silver Deposits, Chungcheongbukdo, Republic of Korea (월유광산산(月留鑛山産) 금(金)-은(銀)광물(鑛物)과 광상(鑛床)의 생성환경(生成環境))

  • Lee, Hyun Koo;Yoo, Bong-Cheal;Jeong, Kwang Young;Kim, Kee Hyun
    • Economic and Environmental Geology
    • /
    • v.27 no.6
    • /
    • pp.537-548
    • /
    • 1994
  • The Weolyu gold-silver deposits at Hwanggan, Chungcheongbukdo, is of a late Cretaceous $(74.24{\pm}1.63Ma)$ epithermal vein-type, and is hosted in the quartz porphyry of late Cretaceous age. Based on mineral paragenetic sequence interpreted from vein structure and mineral assemblages, three stages mineralization were distinguished. A variety of ore minerals occurs including pyrite, sphalerite, chalcopyrite, galena with small amount of electrum, native silver, argentite, pearceite, sb-pearceite, argyrotite. The gangue minerals are quartz, rutile, calcite, apatite, fluorite and rhodochrocite. Wall-rock alteration such as pyritization, chloritization, sericitization, silicification is observed near the quartz veins. Au-Ag minerals were crystallized at middle and late stage of the two mineralization sequences. Results from the analysis of fluid inclusion and thermodynamic calculation indicate that Au-Ag mineral deposits were formed primarily by cooling and dilution of hydrothermal fluids($165{\sim}313^{\circ}C$, 0.4~2.4wt.% equivalent NaCl) with some degree mixing of meteoric water.

  • PDF

Growth of Blue Quartz by Hydrothermal Method (수열법에 의한 청색수정의 성장)

  • Lee Young Kuk;Yu Young Moon;Jung Suk Jong;Koh Jae Cheon;Bak Ro Bak
    • Korean Journal of Crystallography
    • /
    • v.8 no.1
    • /
    • pp.15-19
    • /
    • 1997
  • Single crystals of Co-doped quartz (blue quartz) were grown hydrothermally from the $Na_2CO_3$ solution. The size of as-grown crystal was $100{\times}50{\times}35mm^3$ and the growth rate was 0.55 mm/day under the growth condition of $5wt.\%\;Na_2CO_3$ mineralizer, growth temperature of $343^{\circ}C$ and temperature gradient of $22^{\circ}C$. Visible spectrum showed a typical absorption feature of the synthetic blue quartz near 545, 570 and 643 nm. The concentration of color of the as-grown blue quartz related not to the concentration of cobalt in raw material but to the growth temperature.

  • PDF

SUBMILLIMETER SCALE VARIATION OF THE OXYGEN ISOTOPE COMPOSITION OF GOLD-BEARING QUARTZ VEIN AT THE HISHIKARI DEPOSIT, JAPAN

  • Hayashi, Ken-ichiro
    • Proceedings of the KSEEG Conference
    • /
    • 2003.04a
    • /
    • pp.20-23
    • /
    • 2003
  • Low-sulfidation style ore deposits, the major source of Au, Ag, and Hg, are formed from neutral-pH, reduced hydrothermal solutions close to equilibrium with their host rocks. The waters are low-salinity (〈1 wt % NaCl equiv.) but relatively gas rich (1-2 wt % $CO_2$), and are largely meteoric water. However, the contribution of magmatic components to the epithermal system, its temporal importance, and its relation to the source of ore metals are largely controversial. (omitted)

  • PDF

Geochemical and Stable Isotopic Studies of the Hwacheon Granite (화천 화강암에 대한 지화학 및 안정동위원소 연구)

  • Gyun, Go-Bo;Park, Yeong-Rok
    • Proceedings of the KSEEG Conference
    • /
    • 2003.04a
    • /
    • pp.189-190
    • /
    • 2003
  • Oxygen and hydrogen isotopic data of whole rocks and mineral separates generally provide constraints on the nature of hydrothermal systems. We here report preliminary results of analyses of samples taken from the peraluminous granitic rocks and banded gneiss country rocks in Hwacheon area. Oxygen isotopic values for quartz and feldspar separates from the granitoids in Hwacheon area range from 8.2 to 10.6$\textperthousand$ and 5.8 to 8.5$\textperthousand$, respectively. (omitted)

  • PDF

Fluid Inclusion Study of Quartz Veins in Zogdor Copper Mineralized Area, Southern Mongolia (몽골 남부 족도르 동 광화 지역 석영맥의 유체포유물 연구)

  • Davaasuren, Otgon-Erdene;Lee, Bum Han;Kim, Namhoon;Koh, Sang-Mo;Yoo, Bong Chul;Seo, Jung Hun
    • Korean Journal of Mineralogy and Petrology
    • /
    • v.34 no.2
    • /
    • pp.147-156
    • /
    • 2021
  • We report fluid inclusion study results of copper-bearing quartz veins in Zogdor area, which is located within the Gurvansayhan island arc terrane of Southern Mongolia. At the Zogdor area, structurecontrolled copper mineralization is hosted in granodiorite-porphyry, which emplaced in the late Cretaceous formation. Within this granodiorite porphyry, copper-bearing quartz veins are associated with the hydrothermal alteration that includes quartz-epidote-magnetite, and quartz-magnetite in the propylitic zones. The veins are classified into two types, according to their mineral composition, which occur mainly as chalcopyrite, rare amounts of bornite, magnetite, and pyrite. Fluid inclusions in the quartz veins from the quartz-magnetite±chalcopyrite and quartz-epidote-magnetite veins are two-phase aqueous inclusions having bubble sizes of 5-30 vol.%, evident salinities of 2.0-22.6 wt.% NaCl, and homogenization temperatures of 107-270℃. Based on mineral assemblages of the observed veins, along with the geochemical properties and alteration faces of the host rock, fluid inclusion data show that the study area corresponds to propylitic alteration zone in the porphyry Cu related mineralization.

Skarnization and Fe Mineralization at the Western Orebody in the Manjang Deposit, Goesan (만장광상 서부광체의 철스카른화 작용 및 생성환경)

  • Lim, Euddeum;Yoo, Bongchul;Shin, Dongbok
    • Journal of the Mineralogical Society of Korea
    • /
    • v.29 no.3
    • /
    • pp.141-153
    • /
    • 2016
  • The Manjang deposit is emplaced in Hwajeonri formation comprising limestone that is interbeded with slate and phyllite in the central Okcheon Group. It consists of the Main and the Central orebody of Cu-bearing hydrothermal vein deposit and the Western orebody of iron skarn deposit. Based on coexisting mineral assemblage the skarnization can be divided into prograde skarnization (stage I : clinopyroxene ${\pm}$ magnetite ${\pm}$ quartz, stage II : garnet + clinopyroxene ${\pm}$ magnetite ${\pm}$ quartz) and retrograde hydrothermal alteration (stage III: magnetite + amphibole + quartz ${\pm}$ garnet ${\pm}$ clinopyroxene ${\pm}$ chlorite ${\pm}$ epidote ${\pm}$ fluorite ${\pm}$ calcite, stage IV: fluorite ${\pm}$ pyrrhotite ${\pm}$ chalcopyrite ${\pm}$ amphibole ${\pm}$ quartz ${\pm}$ calcite). Diopside is abundant in stage I, and hedenbergite was produced in stage II and III. Garnet compositions change from grandite to andradite, which suggests a redox transition from relatively reduced to oxidized condition during the skarn formation. Magnetite in stage I and II has relatively constant Fe contents, while in the stage III it has increased Si and Ca concentrations. This variation could indicate that magnetite was more strongly affected by host rocks during the retrograde stage. Sulfur isotope compositions of pyrrhotite and chalcopyrite produced in stage IV are within the range of + 5.9~6.9 ‰, corresponding to igneous origin, but slightly high sulfur isotope values could be attributed to an interaction with host rocks, limestone.

Au-Ag-bearing Ore Mineralization at the Geochang Hydrothermal Vein Deposit (거창 열수 맥상광상의 함 금-은 광화작용)

  • Hong, Seok Jin;Lee, Sunjin;Choi, Sang-Hoon
    • Economic and Environmental Geology
    • /
    • v.55 no.2
    • /
    • pp.171-181
    • /
    • 2022
  • The Geochang Au-Ag deposit is located within the Yeongnam Massif. Within the area a number of hydrothermal quartz and calcite veins were formed by narrow open-space filling of parallel and subparallel fractures in the granitic gneiss and/or gneissic granite. Mineral paragenesis can be divided into two stages (stage I, ore-bearing quartz vein; stage II, barren calcite vein) by major tectonic fracturing. Stage I, at which the precipitation of major ore minerals occurred, is further divided into three substages (early, middle and late) with paragenetic time based on minor fractures and discernible mineral assemblages: early, marked by deposition of pyrite with minor pyrrhotite and arsenopyrite; middle, characterized by introduction of electrum and base-metal sulfides with minor sulfosalts; late, marked by hematite with base-metal sulfides. Fluid inclusion data show that stage I ore mineralization was deposited between initial high temperatures (≥380℃ ) and later lower temperatures (≤210℃ ) from H2O-CO2-NaCl fluids with salinities between 7.0 to 0.7 equiv. wt. % NaCl of Geochang hydrothermal system. The relationship between salinity and homogenization temperature indicates a complex history of boiling, fluid unmixing (CO2 effervescence), cooling and dilution via influx of cooler, more dilute meteoric waters over the temperature range ≥380℃ to ≤210℃. Changes in stage I vein mineralogy reflect decreasing temperature and fugacity of sulfur by evolution of the Geochang hydrothermal system with increasing paragenetic time. The Geochang deposit may represents a mesothermal gold-silver deposit.

Synthesis of Zeolite Using Discharged Fly Ash in an Industrial Complex in Ulsan (울산지역 공단에서 발생되는 비산재를 이용한 제올라이트 합성)

  • Lee, Chang-Han;Park, Jong-Won
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.33 no.5
    • /
    • pp.301-306
    • /
    • 2011
  • In this study, zeolite was synthesized by hydrothermal, fusion, and fusion/hydrothermal methods with fly ash, coal fly ash, and a waste catalyst discharged from thermal power plants and incinerator in Ulsan area. Coal fly ashes (CFAs) and a waste catalyst containing amounts of $SiO_2$ and $Al_2O_3$ ranging from 60.29 to 89.62 wt%. CFAs were mainly composed of quartz and mullite which were assayed by a XRD pattern. Zeolite could be synthesized by CFAs and the waste catalyst when all methods were used. Na-A zeolite (Z-C1, Z-C2, and Z-W5) are mainly synthesized by the fusion method from CFAs and the waste catalyst. Z-C1 and Z-C2 formed by-products, calcite peaks, which is caused by the content of CaO in CFAs and the addition of $Na_2CO_3$ for a synthetic process.

The Trench Exploration of the Gold Deposits of the Tanggung Area of Java, Indonesia (인도네시아 자바 땅긍지역의 금광상에 대한 트렌치탐사)

  • 김인준;이재호;이사로;서정률;김유봉;이규호
    • Economic and Environmental Geology
    • /
    • v.37 no.3
    • /
    • pp.277-290
    • /
    • 2004
  • The trench exploration was carried out on the quartz veins of the Tanggung area of Java, Indonesia. The chemical values of quartz vein samples for hydrothermal alteration zones in this area are defined such as over values of Ag : 2∼190ppm(Celak); 2∼41 ppm(Cilangkap), Au : 21∼17,400 ppb(Celak); 24∼91,100 ppb(Cilangkap), Cu : 9∼3,340 ppm(Celak); 2∼l,600 ppm(Cilangkap), Pb : 60∼52,900 ppm(Celak); 16∼2,960 ppm(Cilangkap), Zn : 12∼13,950 ppm(Celak); 14∼1,520 ppm(Cilangkap), respectively. Two drilling areas, Mt. Subang area(Celak area) and Mt. Cilangkap area(Cilangkap area), have been chosen based on the factors such as, geologic settings associated with gold mineralizations, highly anomalous areas revealed by geochemical survey such as chemical analysis of ore and soil, trench exploration, statistical processing of the chemical analysis, and petrographic studies of igneous rocks related to its mineralization, and graphic presentation of anomalous areas.

Wall Rock Alteration and Genetic Environment of the Milyang Pyrophyllite Deposit (밀양 납석광상의 모암변질작용과 생성환경)

  • Lee, Kangwon;Moon, Hi-Soo;Song, Yungoo;Kim, In Joon
    • Economic and Environmental Geology
    • /
    • v.26 no.3
    • /
    • pp.289-309
    • /
    • 1993
  • Milyang pyrophyllite deposit which was formed by hydrothermal alteration occurs in Late Cretaceous andesitic tuff in the Milyang area, Gyeongsangnamdo. The wall rock alteration and genesis of the Milyang pyrophyllite deposit were studied. The ore minerals are composed dominantly of pyrophyllite accompanied by small amounts of quartz, kaolinite, pyrite, dumortierite and diaspore. The alteration halo of this deposit can be divided into three zones on the basis of mineral assemblage; pyrophyllite, sericite and chlorite zone. The common mineral assemblages of each alteration zone are as follows: (1) pyrophyllite zone; pyrophyllite-quartz-kaolinite-pyrite-dumortierite-diaspore, (2) sericite zone; sericite-quartz-pyrite-kaolinite, and (3) chlorite zone; chlorite-plagioclase-quartz. Major element chemistry shows that characteristic depletion in MgO, CaO, and $Na_2O$ and relative increase in FeO from less altered chlorite zone to extensively altered pyrophyllite zone corresponding to variation in mineral assemblages. The paragenesis of ore minerals, oxygen isotope data, chlorite and illite geothermometry suggest that ore deposit was formed at about $250{\sim}330^{\circ}C$. Both hydrogen and silica activities are high in pyrophyllite zone. Potassium activity increases in sericite zone while hydrogen activity becomes low in chlorite zone. The pyrophyllite zone was formed relatively higher temperature than those of sericite and chlorite zones. The ore fluid was considered to be magmatic water in origin derived from the residual granitic magma which interacted with meteoric water.

  • PDF