• Economic and Environmental Geology
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• v.34 no.2
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• pp.157-166
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• 2001

Numerous base-metal bearing hydrothermal quartz vein deposits occur in the Hunan province of southern China. The Tangguanpu lead-zinc-tin-silver mine is the major producer among these deposits. Lead-zinc-tin-silver mineralization occurs in a single stage of massive quartz veins which filled fractures in fault zones within Paleozoic metasedimentary rocks. Sphalerite, chalcopyrite, galena, pyrite, arsenopyrite and pyrrhotite are the principal sulphide minerals in the Tangguanpu lead-zinc ores with minor amounts of tin- and antimony-bearing sulphides (stannite, teallite, boulangerite and tetrahedrite). Based on the iron and zinc partitioning between coexisting stannite and sphalerite, the formation temperature for this mineral assemblage range from 300$^{\circ}$ to 330$^{\circ}$C, which relatively agree with the upper part of homogenization temperature of fluid inclusion in quartz (20T-358$^{\circ}$C). Fluid inclusion data show that main lead-zine-tin-silver mineralization occurred from $H_{2}O$-NaCl fluids with relatively low salinities (11.2-7.3 wl.% eg. NaCI) at temperatures between 207$^{\circ}$ and 358$^{\circ}$C. The relationship between homogenization temperature and salinity suggests a history of cooling and dilution followed by initial boiling. Evidence of initial fluid boiling may indicate the fluid trapping pressures of 180 bars. The ${\delta}^{34}S{{\Sigma}S}$ values of -5.0 to 1.1 %, indicate an igneous source of sulfur in the Tangguanpu lead-zinc-tin-silver hydrothermal fluids.

• Economic and Environmental Geology
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• v.40 no.6
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• pp.713-726
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• 2007

The Daebong deposit consists of gold-silver-bearing mesothermal massive quartz veins which fill fractures along fault zones($N10{\sim}20^{\circ}W,\;40{\sim}60^{\circ}SW$) within banded gneiss or granitic gneiss of Precambrian Gyeonggi massif. Ore mineralization of the deposit is composed of massive white quartz vein(stage I) which was formed in the same stage by multiple episodes of fracturing and healing and transparent quartz vein(stage II) which is separated by a major faulting event. The hydrothermal alteration of stage I is sericitization, chloritization, carbonitization, pyritization, silicification and argillization. Sericitic zone occurs near and at quartz vein and includes mainly sericite, quartz, and minor illite, carbonates and epidote. Chloritic zone occurs far from quartz vein and is composed of mainly chlorite, quartz and minor sericite, carbonates and epidote. Fe/(Fe+Mg) ratios of sericite and chlorite range 0.36 to 0.59($0.51{\pm}0.10$) and 0.66 to 0.73($0.70{\pm}0.02$), and belong to muscovite-petzite series and brunsvigite, respectively. Calculated $Al_{IV}-Fe/(Fe+Mg)$ diagrams of sericite and chlorite suggest that this can be a reliable indicator of alteration temperature in Au-Ag deposits. Calculated activities of chlorite end member are $a3(Fe_5Al_2Si_3O_{10}(OH){_6}=0.00964{\sim}0.0291,\;a2(Mg_5Al_2Si_3O_{10}(OH){_6}= 9.99E-07{\sim}1.87E-05,\;a1(Mg_6Si_4O_{10}(OH){_6}=5.61E-07{\sim}1.79E-05$. It suggest that chlorite from the Daebong deposit is iron-rich chlorite formed due to decreasing temperature from $T>450^{\circ}C$. Calculated $log\;{\alpha}K^+/{\alpha}H^+,\;log\;{\alpha}Na^+/{\alpha}H^+,\;log\;{\alpha}Ca^{2+}/{\alpha}^2H^+$ and pH values during wall-rock alteration are $4.6(400^{\circ}C),\;4.1(350^{\circ}C),\;4.0(400^{\circ}C),\;4.2(350^{\circ}C),\;1.8(400^{\circ}C),\;4.5(350^{\circ}C),\;5.4{\sim}6.5(400^{\circ}C)\;and\;5.1{\sim}5.5(350^{\circ}C)$, respectively. Gain elements (enrichment elements) during wallrock alteration are $K_2O,\;P_2O_5,\;Na2O$, Ba, Sr, Cr, Sc, V, Pb, Zn, Be, Ag, As, Ta and Sb. Elements(Sr, V, Pb, Zn, As, Sb) represent a potentially tools for exploration in mesothermal and epithermal gold-silver deposits.

• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.154-157
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• 2005

제주도 남제주군 사계리 해안에서 발견된 사람과 각종 동물 발자국 화석의 생성 연대를 규명하기 위하여 문화재청에서 한국지질자원연구원에 연구 용역을 의뢰하여, 사람 발자국 화석이 산출되는 지층에서 유기물의 탄소동위원소 연대 측정과 광여기루미네선스(Optically Stimulated Luminescence, OSL) 연대 측정을 실시하였다. 그 결과, Humin 유기물에 대한 탄소동위원소 측정값은 상부로부터 $10,901{\pm}60$년, $13,513{\pm}65$년 그리고 $15,161{\pm}70$년이고, Humic 유기물에 대한 탄소동위원소 측정값은 $9,289{\pm}90$년, $8,622{\pm}90$년 및 $8,098{\pm}50$년 이며, OSL 연대 측정 방법에 의하면 $6,800{\pm}300{\sim}7,600{\pm}500$년이다. 이 측정 자료에서 한국지질자원연구원은 탄소동위원소에 의한 측정값은 배제하고, OSL 연대 측정값인 $6,800{\pm}300{\sim}7,600{\pm}500$년을 사람 발자국 화석의 생성 연대로 해석하였다. 그러나 Humin 유기물에 의한 탄소동위원소 측정값을 배제한 가장 중요한 이유로 Humin 유기물이 산성 또는 알칼리에 잘 녹지 않기 때문에 재순환되어 발자국 화석이 생성될 당시 외부에서 유입되어 더 오래된 연대값을 나타낸다고 주장하였는데, 이러한 주장은 아무런 근거가 없다. 또한 송악산의 분출이 약 10,000년 이내에 분출하였다는 명확한 근거가 없으며, 석영을 이용한 OSL 연대 측정은 연대를 결정하기 위해 고려되는 여러 요소들에 수반되는 불확실한 요소(예를 들면, 수분 함량 문제 등)들로 인해 탄소동위원소 연대 측정에 비해 정밀도와 정확도가 낮으며, 특히 화산 기원 석영의 경우, 정확한 등가선량의 측정이 어렵기 때문에 연대 측정에 오류가 발생할 수 있음이 잘 알려져 있고, 주변의 화산 활동으로 인한 열수에 의해 OSL 신호가 영향을 받을 수 있는 가능성을 배제할 수 없다. 따라서 현재의 연대 측정 결과만으로 사람 발자국 화석의 생성 연대를 결정하는 데 가장 신뢰성이 있는 자료는 Humin 유기물에 의한 탄소동위원소 연대 측정값이며, 이를 근거로 할 때, 사람 발자국 화석의 생성 연대는 $13,513{\pm}65{\sim}15,161{\pm}70$년 사이로 보는 것이 가장 합리적이고 타당하다.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.155-162
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• 2002

There are many typical epithermal deposits scattering in the Taran of central Kalimantan. Indonesia. To get the shallow geological information, we carried out the geophysical exploration: spontaneous potential survey, in-suite magnetic susceptibility measurement and relistivity survey method in this area for a few weeks from September 30th to October 27th in 1997. SP survey (Fluke 27 multimeter)/magnetic susceptibility (EK -7 meter) measurement was carried out with a 250m$\times$10m lattice net in N45$^{\circ}$W direction. The dipole-dipole array resistivity survey was conducted with an electrode spacing of ${\alpha}$=30 m and electrode separation index n=7 at the line 5. The result shows that was the gold bearing quartz vein area can be divided into two type lone: low sulfidation type and high sulfidation type zone. The low resistivity value in the survey line 5 indicated a fracture Bone associated with the high sulfidation zone.

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.46-55
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• 1999

Fluid inclusions in granite and hydrothermal quartz indicate that three fluids have affected the Sannae granite. The earliest fluid is represented by three-phase aqueous fluid inclusions with high salinity (38 to 46 wt.% NaCl equiv.). It was exsolves from a crystallizing melt and trapped at a relatively high-pressure condition. The secong fluid is represented by two-phase aqueous fluid inclusion with low entectic temperatures (< $-40^{\circ}C$). low- to moderate salinity (3 to 24.0 wt.% NaCl equiv.) and high homogenization temperatures$ ($309^{\circ}C$$473^{\circ}C$)($. This fluid was trapped at higher pressures than 300-500 bars and precipitated molybdenite and wolframite in quartz veins. It was probably generted by fluid-host rock interactions since they show a wide range of salinity within a narrow range of homogenization temperatures. The final fluid is represented by an aquenous fluid boiling that separated into high-salinity (34-38 wt.% NaCl equiv.) and low-salinity fluid (0 to 8.7 wt.%) at $303-376^{\circ}C$ and 50-150 bars. These boiling fluids precipitated euhedral quartz in miarolitic cavities. The compositions of the final fluid was rather complex in the $H_2$O-NaCl-KCI-$FeCl_2$ system. The Sannae granite was a locus for repeated fluid events including magmatic fluids during the final stage of crystallization, the convection of hydrothermal fluids causing a fluid ascending, fluid boiling, and the local W-Mo mineralization and formation of miarolitic cavities due to thermal, tectonic and compositional properties of the felsic granite.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.273-282
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• 1984

The Buncheon manganese ore deposits occur in vein along the fault of $N20^{\circ}E$, cutting the foliation of Yulri Series. The deposits consist of primary manganese silicate ores in the deeper part and superficial manganese oxide ores near the surface. The spatial distribution of manganese oxide ores with respect to the manganese silicate ores suggests that the manganese oxide ores are the supergene oxidation product of the manganese silicate ores. Manganese silicate ores consist mainly of fine-to coarse-grained pyroxmangite with minor rhodochrosite, quartz, sulfides and chlorite. Manganese oxide ores are composed of supergene manganese oxides such as nsutite, birnessite, manganite and todorokite, and other associated minerals. Paragenetic sequence of formation of the manganese minerals are as follows: $\array{{rhodochrosite{_{\rightarrow}^o}todorokite{_{\searro}^o}}\\pyroxmangite{_{\line(10){90}}^o}{\nearro}}birnessite{_{\rightarrow}^o}nsutite{_{\rightarrow}^s}manganite$ In order to elucidate the mineralogy of the manganese minerals, microscopic, X-ray, IR spectroscopic, and thermal studies were made for manganese and associated minerals.

• Economic and Environmental Geology
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• v.24 no.1
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• pp.9-20
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• 1991

Gusi pyrophyllite deposit is located in the Haenam volcanic field in the southwestern part of the Korea Peninsula. This area is known for the occurrences of pyrophyllite, alunite and dickite. This volcanic field is composed of andesite, rhyolite and pyroclastic rocks of late Cretaceous age The pyroclastic rocks are hydrothermally altered to pyrophyllite and kaolin minerals forming the Gusi deposits. The hydrothermally altered rock can be classified into the following zones on the basis of their mineral assemblages: quartz, pyrophyllite, dickite and illite-smectite zones, from the centre to the margins of the alteration mass. Such mineral assemblages indicate that the country rocks, most of which are the lower Jagguri Tuff, were altered by strongly acidic hydrothermal solutions with high aqueous silica and potassium activity and that the formation temperature of pyrophyllite is higher than $265^{\circ}C$. The mechanism of the hydrothermal alteration is considered to be related to felsic magmatism.

• Journal of the Korean earth science society
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• v.29 no.7
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• pp.551-558
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• 2008

The Soowang deposits occur in the quartz veins that were filled fissures in the middle Cretaceous porphyritic granite and/or the Precambrian Sobaegsan gneiss complex. Paragenetic studies suggest that the vein filling can be divided into four identifiable stages. Sphalerites were deposited by the cooling fluids at stages I, II, and III. The results of microscopic observation and EPMA analysis suggest that the chalcopyrite dots and disease in sphalerite are replacement products by later hydrothermal solution at the early stage III. The inferred processes of chalcopyrite disease are as follows: (1) Fe enrichment to the margins and along the cracks of the Fe-poor sphalerite by Fe-rich solution, (2) Formation of chalcopyrite dots in the Fe-enriched sphalerite formed at the stage II, and Fe reduction of sphalerite near the chalcopyrite dots by Cu-bearing solution, (3) Formation of "chalcopyrite disease" penetrating the compositional zoning of sphalerite at the early stage III.

• The Journal of the Petrological Society of Korea
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• v.11 no.3_4
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• pp.259-270
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• 2002

A small granodiorite-quartz monzonitic stock containing sericitic and propylitic alteration assemblages hosts a Cu-W breccia-pipe deposit in the southeastern Cyeongsang basin. The mineralized breccia-pipe contains angular to subangular brecciated fragments of granitic rocks showing clast-supported textures. An assemblage of quartz, tourmalines, sulfide minerals (mainly chalcopyrite, arsenopyrite and pyrrhotite) and calcite was precipitated as a hydrothermal cement between the brecciated fragments. A tourmaline aureole surrounds the breccia pipe. Extensive tourmalinization of the granitic rocks near and within the pipe and no tourmalinization in the sedimentary and volcanic rocks. The tourmalines are marked by Fe-rich, black charcoal-like schorl (80 mol% schorl relative) nearer the schorl-dravite solid solution. The chemical changes in the hydrothermal fluid are reflected by variations in compositional Boning from cores to rims. They generally contain cores with low values of Fe/(Fe+Mg) and high values of Na/(Na+ca) relative to rims. This is because of an increase Fe and Ca contents toward rims. The main trend of these variations is a combination of the exchange vectors Ca(Fe, Mg) $(NaAl)_{- }$ $_1$ and $Fe^{3}^{+}$ $Al_{[-10]}$ $_1$ It is thought that boiling causes the loss of $H_2$ into the vapor phase resulting in the oxidation of Fe in the aqueous phase. pH of the melt would be one of important controlling factors for the tourmaline stability. The tourmalines could be precipitated when the system evolved to the acidic hydrothermal regime as most hydrothermal brines and acidic gases exsolved from the magma. The Ilgwang tourmaline crystallization is products of hypogene orthomagmatic hydrothermal processes that were strongly pipe-controlled.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.25-39
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• 1994

The Deogbong napseok clay deposit which is composed mainly of dickite and pyrophyllite has been formed by hydrothermal alteration of the Late Cretaceous volcanic rocks consisting of andesitic tuff and andesite. The mineralogy of the napseok ores and the hydrothermal alteration processes have been studied in order to know the nature of the interaction between minerals and fluids for the formation of the deposit. Chemical distribution shows that alkali elements and silica were mobile but alumina was relatively immobile during the hydrothermal processes. It is evident that enrichment of alumina and leaching of silica from the host rock led to the formation of the napseok ore, whereas the enrichment of silica in the outer zone of the deposit gave rise to the silica zone. A large amount of microcrystalline quartz closely associated with dickite and pyrophyllite suggests the increasing activity of silica. Thus Si which was released away from the argillic zone by the increasing activity of silica. Thus Si which was released away from the argillic zone by the increasing activity of silica solubility moved out precipitating in the margin of the deposit to form the silica zone. Variation in dickite crystallinity implies the local change in the stability of the system. Thermodynamic calculation shows that the invariant point of pyrophyllite-dickite (kaolinite)-diaspore-quartz assemblages at 500 bars in the system $Al_{2}O_{3}-SiO_{2}-H_{2}O$ is about 300 $^{\circ}C$. Based on the mineral assemblages and the experimental data reported, it is estimated that the main episode of hydrothermal alteration occurred at least above 270 to 300 $^{\circ}C$ and $X_{CO_2}$ <0.025. Mineral occurrence and chemical variation indicate that the activity of Al is high in the upper part of the deposit, whereas the activity of Si is high in the lower part and the margin of the deposit. The nonequilibrium phase relations observed in the Deogbong deposit might be due to local change in intensive thermodynamic variables and fluid transport properties that resulted in the formation of nonequilibrium phases b of several stages.