The Changing Patterns of Demand-Supply and Role of Mineral Resources in Economic Growth during Industrialization of the Republic of Korea

윤석규,Yun, Suckew The Korean Society of Economic and Environmental G 1985 자원환경지질 Vol.18 No.1

A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly s

스카른 광상(鑛床)과 관계화성암(關係火成岩)의 심부동일기원(深部同一起源)

윤석규,Yun, Suckew 대한자원환경지질학회 1985 자원환경지질 Vol.18 No.2

Whether a skarn deposit in carbonate host occurs in contact with certain igneous mass or not has been a general criterion in identifying the igneous rock that genetically relates to the skarn deposit. It is well known, however, that there are many skarn deposits which are not close to any given igneous contact but are far away from the contact. In this paper the reason why such deposits can be formed at a distance from the contact as mentioned is expressed based on the concept that skarn deposits and related igneous rocks are genetically connected at depth where ore-forming fluids emanate from magma and are removed upwards; the movement of ore-forming fluids separated from magma at any depth may have a tendency to infiltrate upward in bulk rather than to diffuse laterally; the paths of magma and cogenetic ore-forming fluids may be identical at lower depths but the latter can be diverted from the former with upward movement so that the positions of the skarn deposits which resulted from the ore-forming fludis at upper levels can be distant from the igneous contacts on a given horizontal section. Statistics indicate that the majority of exoskarns are found at distances up to 800 meters or rarely up to 3,000 meters from igneous contacts and endoskarns up to 600 meters or more. Numerous case studies of skarn deposits in various parts of the world support the above reasoning indicating a general downward convergency of skarn orebodies and related igneous masses with depth. A typical example of this situation is well demonstrated at the Keumseong molybdenum deposit, which is apart from the Jecheon granite on the surface but gets closer to the granite body with depth and finally is intertongued with the granite apophyses in its root zone. Another case for skarn deposit not associated with igneous contact either laterally or vertically but with a deep-seated distal igneous mass is the Sangdong scheelite deposit; 700 meters below the scheelite orebody a blind pluton of muscovite granite, which intruded into the Precambrian crystalline schist, has been recently discovered by deep drilling.

대전서남지대(大田西南地帶)에 있어서의 옥천대(沃川帶) 우라늄광상(鑛床)에 대(對)한 광물학적(鑛物學的) 및 지화학적(地化學的) 연구(硏究)

윤석규,Yun, Suckew 대한자원환경지질학회 1984 자원환경지질 Vol.17 No.4

Uraniferous black slates of the Okchon sequence occur in Koesan (northeast) through Miwon-Boun (middle) to the southwest off Taejon (southwest) within the Okchon fold belt. The Uraniferous balck slates in the southwest off Taejon are particularly well developed in Chubu (northeast) and Moksso-ri (middle) areas whereas they are less developed in Jinsan (southwest) area. The uraniferous beds range from less than a meter to 40 meters in thickness and range from less than 0.02% $U_3O_8$ (cut-off-grade) to 0.05% $U_3O_8$ in the southwestern district off Taejon. Electron microprobe analysis of uranium-minerals found in graphitic slate samples enables to estimate their major compositions semi-quantitatively so that uraninite, ferro-uranophane and chlopinite are tentatively identified. Uranium-minerals are closely associated with carbon and metal sulfides. Correlation analysis of trace element concentrations revealed that U and F.C., and U and Mo are lineary correlative respectively and their correlation coefficients are positively high whereas those of U and V, U and Mn, and U and Zr are negatively low, implying that uranium mineralization has been closely related with concentrations of carbon and molybdenum. Stable isotope analyses of pyrite sulfur range widely from +11.5% to -23.3% in ${\delta}^{34}S$ values whereas those of graphite carbon fall within a narrow range between -23.3% and -28.9% in ${\delta}^{13}C$ values. The wide range of ${\delta}^{34}S$ values suggests that the sulfur could be of meteoric origin rather than of igneous source. The narrow range of ${\delta}^{13}C$ values, which are close to those of coal, indicates that the graphite is organic carbon in origin. Therefore, it is concluded that the uranium mineralization in the Okchon sequence took place primarily in sedimentary environment rich in organic matter and sulfide ion, both of which served as the reducing agents to convert soluble uranyl complex to insoluble uranium dioxide.

옥천지향사대(沃川地向斜帶)의 진화(進化)와 광화작용(鑛化作用)

윤석규,Yun, Suckew 대한자원환경지질학회 1971 자원환경지질 Vol.4 No.2

About four hundred deposits of iron, talc, fluorite, tungsten, molybdenum, lead, zinc and other polymetallic mineral deposits were plotted on the Ore Distribution Map of the Ockcheon Geosynclinal Area. These mineral deposits plotted on the map can be divided into the several metallogenic zones by the consideration of their geologic background including the sedimentary and tectonic cycles and the igneous activities in the geosynclinal evolution, as follows: a. Chungju iron and talc zones. b. Cheong-san copper bearing iron sulphide zone c. Kumsan-Muju fluorite-polymetallic zones. d. Cheong-an Puyong and Ein Suckseong gold zone e. Hwang-gan Seolcheon and Sangju gold zones. Chungju iron zone originated in the iron bed in the Kemyongsan Series corresponding to the Pre-Ockcheon Cycle of evolution history. In early period of the Ockcheon Cycle, Hyangsanri quartzite and Munjuri phyllitic formation corresponding to the lower terrigenous sequence were not mineralized while the next sequence of the Samsungsan basic igneous-metamorphic formation and the Changri limestone formation were mineralized by the copper bearing iron sulphide and the fluorite-polymetallic deposits respectively. Two generations of the gold zones are recognized. The earlier generation distributes directionaly in the outside of the Ockcheon sedimentary belt was followed by the earlier grantitic invasion of Jurasic in age, while the later generation scatters at random which was related to the nondirectional Cretaceous granitic intrusion of the Post-Ockcheon Cycle. Conclusively speaking, it was disclosed that the endogenic mineralization in the Ockcheon geosyn clinal zone was not conspicuous in its inner sedimentary belt except its limestone area but in its outer peripheral granitic or gneissic zones, and the related igneous activities occured in the Post-Ockcheon Cycle of evolution history.

옥천대(沃川帶)의 지질(地質) 및 광물자원(鑛物資源)에 관(關)한 연구(硏究) -무암사화강암(務岩寺花崗岩) 주위에서의 광화작용(鑛化作用)에 관(關)하여-

윤석규,김규한,우종상,Yun, Suckew,Kim, Kyu Han,Woo, Jong Sang 대한자원환경지질학회 1986 자원환경지질 Vol.19 No.no.spc

Hundred mineral deposits including W-Mo, Pb-Zn-Cu, fluorite and talc occur in the Cambre-Ordovician limestone contacting with the Cretaceous Muamsa and Wolak granitoids in the Susanri-Hwanggangri mineralized zone. In most mineral deposits characterized by metasomatic replacement, skarn and hydrothermal vein types, two distinct tendencies were found as W-Mo mineralization in or/and near granitoid batholith and ($Pb-Zn-Cu(CaF_2)$) mineralization which is gradually increased toward the batholith. W-Mo veins of extensive vein system occupy northly striking fractures whilst $Pb-Zn-Cu-CaF_2$ veins strike northeast or northwest. In this work, three representative lead-zinc-copper deposits choosing the Dangdu, Useog and Eoksu mines were dealt with in detail. Skarn ore bodies in the Dangdu mine were grouped into early diopside rich clinopyoxene-garnet, barren skarn and ore bearing late hedenbergite rich clinopyroxene-garnet skarn. Temperature and $X_{CO_2}$, obtained from hedenbergite-andradite-calcite-quartz mineral equilibria in the Dangdu ore deposits were $580{\sim}650^{\circ}C$ and 0.15~0.3, respectively. Fluid inclusien evidence in the Useog mine indicates that main stage mineralization temperature ranges from 224 to $389^{\circ}C$ with a salinity of 2~17 equivalent wt. percent NaCl. Sphalerites from the Dangdu and Useog mines have 16~17.7 mole percent in FeS which is relatively consistent to those of some other lend-zinc ore deposits in South Korea. Filling tcmjCerature of fluid inclusion frem the Eoksu mine shows deposition of ore within the temperature ranges from 237 to $347^{\circ}C$ and within the salinity ranges from 2.6 to 10.77 equivalent wt. percent NaCl.

형석광상(螢石鑛床)의 지질온도측정(地質溫度測定) 연구(硏究) 특(特)히 충북(忠北) 월악산지대(月岳山地帶) 및 천일광산(天一鑛山) 형석(螢石)의 연구(硏究)를 중심(中心)으로

윤석규,Yun, Suckew 대한자원환경지질학회 1973 자원환경지질 Vol.6 No.4

Temperature environments of the formation of fluorite deposits in the Wolaksan area and the Cheonil Mine, Chungcheongbuk-Do are presented and interpreted in brief. These deposits occur more or less near the contact zone between the Paleozoic limestone formations and the Cretaceous biotite granites as a number of hydrothermal veins or replacement deposits. The homogenization temperatures of fluorite crystals from the Wolaksan area fall within the narrow range of $149{\sim}167^{\circ}C$, of which lower limit is quite high, while those of the Cheonil Mine show wide range of $126{\sim}177^{\circ}C$, which indicates much lower mean temperature of formation. If the possible correction for pressure, which may not exceed $+30^{\circ}C$ as the depth of the deposits was 1.5km, were applied, the possible highest value of the true formation temperatures of fluorites in both area might be reached to around $200^{\circ}C$ that means these deposits were formed as a series of early products of the epithermal stage of hydrothermal processes.

태백산광화대(太白山鑛化帶) 연화(蓮花)-거도광산(巨道鑛山)에 있어서의 스카른과 광석광물(鑛石鑛物)의 수반관계(隨伴關係) 및 상평형(相平衡)

윤석규,Yun, Suckew 대한자원환경지질학회 1983 자원환경지질 Vol.16 No.1

The Yeonhwa (I, II) and Keodo mines, neighboring in the middle part of the Taebaegsan mineral belt, contain three distinct classes of skarn deposits: the zinc-lead skarn at Yeonhwa (I, II), the iron skarn at Keodo south (Jangsan orebodies), and the copper skarn at Keodo north (78 orebodies). The present study characterizes the three classes of skarn deposits mainly in terms of skarn/ore associations examined from chemical compositional point of view, and applies existing quantitative phase diagrams to some pertinent mineral assemblages in these mines. At Yeonhwa I the Wolam I orebody shows a vertical variation in skarn minerals ranging from clinopyroxene/garnet zone on the lower levels through clinopyroxene (without garnet) zone on the intermediate levels, and finally to rhodochrosite veins on the upper levels and surface. Ore minerals, sphalerite and galena, associate most closely with the intermediate clinopyroxene zone. At Keodo, the Jangsan iron skarn hosted in quartz monzodiolite as a typical endoskarn, shows a skarn zoning, from center of orebody to outer side, magnetite zone, magnetite/garnet zone, garnet clinopyroxene zone, and clinopyroxene/epidote/plagioclase zone. The 78 copper skarn in the Hwajeol limestone indicates a zoning, from quartz porphyry side toward limestone side, orthoclase/epidote zone, epidote/clinopyroxene zone, and clinopyroxene/garnet zone; chalcopyrite and other copper sulfides tend to be in clinopyroxene/garnet zone. Mioroprobe analyses of clinopyroxenes and garnets from the various skarn zones mentioned above revealed that the Yeonhwa zinc/lead skarns are characterized by johansenitic clinopyroxene (Hd 25-78, Jo 15-23) and manganoan andraditic garnet (Ad 13-97, Sp 1-24), whereas the Jangsan iron skarn at Keodo by Mn-poor diopsidic clinopyroxene (Di 78-93, Jo 0.2-1.0) and Mn-poor grossularitic grandite (Gr 65-77, Sp 0.5-1.0). The 78 copper skarn at Keodo is characterized by Mn-poor diopsidic-salite (Di 66-91, Jo 0.2-1.1) and Mn-poor andraditic grandite(Ad 40-74, Sp 0.5-1.1). The compositional charateristics of iron, copper, and zinc-lead skarns in the Yeonhwa-Keodo mines are in good correlations with those of the foreign counterparts. Compiling a $T-XCO_2$ phase diagram for the Jangsan endoskarns, a potential upper limit of temperature of the main stage of skarn formation is estimated to be about $530^{\circ}C$, and a lower limit to be $400^{\circ}C$ or below assuming $XCO_2=0.05$ at P total=1kb. Applying a published log $fS_2$-log $fo_2$ diagram to the Keodo 78 and Yeonhwa exoskarns, it is revealed that copper sulfides and zinc-lead sulfides do not co-exist stably below log $fS_2=-4$ and log $fO_2=-23$ at $T=400^{\circ}C$ and ${\times}CO=1$ atm.

A Land Resources Survey of the Mula Area, S. E. Spain

윤석규,Yun, Suckew The Korean Society of Economic and Environmental G 1973 자원환경지질 Vol.6 No.1

아건조지대(亞乾燥地帶)인 동남(東南)스페인 Mula지역(地域)에서 약(約)$400km^2$에 걸쳐 1972년(年) 봄에 실시(實施)된 본조사(本調査)의 주목적(主目的)은 지형학(地形學)을 응용(應用)하여 조사지역(調査地域)을 유사(類似)한 지질(地質), 지형(地形), 토양(土壞) 및 식물(植物)로서 특징(特徵)지어지는 일련(一連)의 land complex로 분석(分析) 결합(結合)하여 내재(內在)된 토지자원(士地資源)(land resources)의 특질(特質)을 연구(硏究)함에 있었다. 본지역(本地域)은 서북부(西北部)의 삼(三)첩~백악기(白堊記) 석회암(石灰岩), Eocene 암석암(岩石岩) 및 Oligocene 사암(妙岩)으로 된 습곡산맥(褶曲山脈)과 구릉지대(丘陵地帶), 중앙부(中央部)의 Miocene marl과 이를 덮는 석회암(石灰岩)의 개암층(蓋岩層)으로 된 일련(一連)의 탁상지군(卓狀地群)과 이에 병행(倂行)하는 동(同) marl과 충적층으로 된 Mula 강(江) 유역(流域)의 저지대(低地帶), 그리고 동남부(東南部)의 Miocene marl 및 석회질(石灰質) 또는 묘질암(妙質岩)의 호층(互層)으로 된 cuesta 지대(地帶)로 구성(構成)되어 있으며 이들은 동북동일서남서(東北東一西南西)의 방향(方向)으로 평행배열(平行配列)을 이루어 기반암층(基盤岩層)의 동사구조(同料構造)와 이에 대한 차별침식(差別浸蝕)의 결과(結果)를 나타내고 있다. 총(總) 26개(個)의 land complex로 분류(分類)된 본지역(本地域)의 토양(土壞)은 대체(大體)로 담색(淡色) 석회질(石灰質) 광물성토양(鑛物性土壤)으로 pH 7 이상(以上)의 강한 알칼리성(性)을 띰으로서 주(主)로 이회질(泥灰質) 모물질(母物質)로 부터 이루어 졌음을 반영(反映)하고 있으며 지표(地表)의 기복(起伏) 조건(條件)에 의(依)해 slope catena를 이루고 있다. 본지역(本地域)에 있어서의 토지이용(土地利用)은 주(主)로 Sequra 및 Mula 강(江) 유역(流域)의 단구상(段丘狀) 충적층상에서의 영구관개(永久灌漑)에 의(依)한 Citrus 재배(栽培)와 저구배(低句配) 경사지(傾斜地)에 있어서의 건륙(乾陸) 곡물경작(穀物耕作)으로 특징(特徵)지어 진다. 고구배지대(高勾配地帶)나 shrub 지대내(地帶內)에서의 선구적(先驅的) 개(閒)간은 주(主)로 천수(天水)가 모이는 배수곡(排水谷)을 따라 이루어지고 있으나 이미 그 한계(限界)에 달하고 있다. 아건조기후하(亞乾燥氣候下)에 있는 본지역(本地域)에 있어서 물의 혜택(惠擇)은 천연(天然) 및 경작식물(耕作植物)의 소장(消長)에 있어서 가장 근본적(根本的) 요인(要因)이며 표토유실(表土流失) 및 우곡작용(雨谷作用)은 자연보존(自然保存) 및 토지자원관리상(土地資源管理上) 기본적(基本的)으로 고려(考慮)해야 할 중요(重要)한 요인(要因)이다. A land resources survey in the semi-arid area, Mula in S. E. Spain, of $400km^2$ is compiled. The basic aim of the project is to investigate the intrinsic qualities of the land resources of the area by means of applying an integrated method of natural resources survey mainly concerning with analysis and synthesis of land complexes, each of them represents an area or a group of areas with similar patterns of landforms, soils and vegetation, based on a geomorphological approach. The area is characterized by a linear arrangement of relief pattern with an asymmetric homoclinal repetition of slope attitudes elongating WSW-ENE, dipping steeply on the NW sides and gently on the SE sides, which have been resulted from the post-Alpine folding of the Triassic to Cretaceous limestone, the Eocene limestone, the Oligocene sandstone and the lower Miocene limestone and marl, and the post-lower Miocene faulting, tilting and subsequent differential erosion of the Miocene sedimentary formations. An integrated body of information in geology, landforms, soils and vegetation, which are significantry interrelated as an environmental complex, has been obtained. Using this data, 26 land complexes developing on the various situations of landforms, such as folded mountain ranges, tilted tablelands, bevelled cuestas, degraded hill-lands associating with enormous foots lopes, undulating terrains and terraced or flat plains, have been differentiated, mapped and described. The soils of the area are mostly light colored calcic lithosols which have been derived dominantly from the marly parent materials and developed into remarkable slope catenas in some places depending on the relief conditions. The land uses of the area are mainly characterized by the perennially irrigated cultivation of citrus orchards along the terraced alluvial deposits fringing the Segura and Mula River, and the dry-land cereal cultivation on gentler slopes. Pioneer dry-land cultivations within the shrubs on steeper slopes are restricted to the unchannelled tributary drainage floors. The availability of water is a fundamental controlling factor for existence of native and cultivated vegetation as a whole, and a number of active processes including sheet wash and gully erosion, especially on the scarp slopes, are the other important factors to be considered in conservation and management of the land in the area.

Geomorphological Approach in Geological Mapping of the Miocene and Post-Miocene Formations in the Albudeite Area, Spain

윤석규,Yun, Suckew The Korean Society of Economic and Environmental G 1973 자원환경지질 Vol.6 No.3

동남(東南) Spain의 지중해(地中海) 연안(沿岸)에 위치(位置)한 Albudeite 지형적(地形的)으로 잘 표현(表現)된 Miocene의 marl 및 석회암층(石灰岩層)과 이를 덮는 Pliocene 및 Ouaternary의 다양(多樣)한 퇴적층(堆積層)이 잘 노출(露出)되어 복잡(複雜)한 분포(分布)를 보이고 있다. 즉(卽) 본지역(本地域)의 중앙부(中央部)를 서(西)에서 동(東)으로 흐르는 Mula강(江)을 사이에 두고 북부(北部)에는 NE 및 NW계(系)의 단층운동(斷層運動)에 의(依)해 이루어진 경근지괴(傾勤地塊)로서의 Upper Miocene의 marl과 석회암(石灰岩) 협층(挾層)으로 된 tableland가 연(軟)한 marl층(層)을 덮는 굳은 아어란상(亞魚卵狀)~아쇄설성(亞碎屑性) 석회암층(石灰岩層)의 capping effect에 의(依)하여 이루어져 있고 지역남부(地域南部)에는 이 tableland의 지표면(地表面)(석회암(石灰岩) cap)과 거의 동사적(同斜的)인 bevelled cuesta가 연(軟)한 marl과 굳은 석회암(石灰岩)(아쇄설성(亞碎屑性) 합(合) Ostracod) 또는 사질암(砂質岩) 협층(挾層)의 차별침식(差別侵飾)에 의(依)하여 이루어져 있어 이들을 지형적(地形的)으로 돌출(突出)된 양(兩) 석회암층(石灰岩層)을 Key bed로 하여 Upper Miocene을 다시 하부(下部), 중부(中部) 및 상부(上部)를 삼분(三分)하였다. 남부(南部) Cuesta의 scarp slope에 이루어진 격심(激甚)한 양곡측면(兩谷側面)과 북부(北部) tablelanl의 남측(南側) footslope에 급재(級在)하는 퇴화구준(退化丘俊)의 침식측면등(侵蝕側面等)에 노출(露出)되는 marl과 이를 덮는 colluvium, alluvium 또는 capped gravel과의 복잡(複雜)한 boundary tracing에 있어서와 또한 Mula강(江) 유역(流域)에 상봉(相逢)한 고도(高度)로 분포(分布)되는 일련(一連)의 단구상(段丘狀) 충적층등(沖積層等)에 대(對)한 층서(層序) 수립(樹立)과 mapping에 있어서는 이들에 대(對)한 지형(地形) 발달사적(發達史的) 이해(理解)와 항공사진해석의 적용(適用)이 매우 효과적이어서 임존지질천(臨存地質踐)에는 Mula강(江)의 channel에 따르는 협장(挾長)한 사기층(四紀層)을 제외(除外)하고는 Upper Miocene (M3) 일색(一色)으로 되어 있었으나 이번 시도(試圖)에 의(依)하여 총(總)9개(個)의 층서적(層序的) 단위(單位)로 세분(細分)하여 mapping할 수가 있었다. Gemorphological and photogeological techniqes are applied to the problem of geological mapping of a semi-arid area, Albudeite, Southeastern Spain. As a result of this, a geological and surface materials map is made which shows the upper Miocene formation, which mainly consists of marl, limestone and sandstone, is further subdivided into three members, i. e. lower, middle and upper, and the post-Miocene deposits were differentiated into seven stratigraphic units, and mapped. The relationships between geology, landforms and land comlexes previously reognized have been reviewed. The methods adopted have proved to be valuable in interpreting and mapping a compex relationship in which highly variable bedrock outcrops and shallow surface materiales produced under sub-aerial conditios.

옥천대(沃川帶)의 지질(地質) 및 광물자원(鑛物資源)에 관(關)한 연구(硏究) -평창(平昌)~주천지역(酒泉地域)에 있어서의 광화작용(鑛化作用)-

윤석규,소칠섭,김규한,Yun, Suckew,So, Chil Sop,Kim, Kyu Han 대한자원환경지질학회 1986 자원환경지질 Vol.19 No.1

A group of 16 $Zn+Pb{\pm}Ag$ deposits distributed in the Pyeongchang-Jucheon area, Kangwon-do, South Korea, were semi-regionally investigated. These deposits are contact metasomatic and/or hydrothermal replacement types hosted in the carbonate-dominated Cambrian Machari Formation and Ordovician Ibtanri Formation, and also in the carbonate interbeds of the Precambrian argillic metasediments. Comparing some key aspects of the individual deposits, it is found that the ore deposits hosted in the Machari and Ibtanri Formations are mostly of steeply-dipping chimneys with or without skarn minerals and are rich in Ag and Pb>Zn in metal grade whereas those occuring in the carbonate interbeds of the Precambrian argillic metasediments are gently-dipping conformable lenticular orebodies mostly with skarn minerals and are generally poor in Ag and Zn>Pb. The skarn mineralization in the area appears to have occurred during the lower Cretaceous (118.7Ma) to mid-Cretaceous (107.8Ma) time assumed from the K-Ar dates of the Dowon and Pyeongchang granites which are closely associated with the skarn ore deposits. The Rb/Ba/Sr ratios of these granites indicate that they are of strongly differentiated anomalous granites, and the Nb vs. Y and Rb vs. Y+Nb plots fall on the field of volcanic arc setting. The contact aureoles are zoned, giving the sequence in order of increasing distance from igneous contact: garnet-wollastonite, granet-wollastonite-clinopyroxene and garnet-clinopyroxene in such as the Pyeongchang and Yeonwol 114 areas. Electron microprobe analyses reveal that garnets and clinopyroxenes are generally low in Fe and Mn. Garnets are grossular to intermediate grandite except for those from the Ogryong exoskarn which are richer in andradite, pyrope and spessartine fractions. This indicates that the oxidation state of skarn-forming environment at Ogryong was higher than at the other deposits. Clinopyroxenes are mostly salitic except for those from the Ogryong exoskarn which involve considerable amounts of hedenbergite and johansenite fractions. The ${\delta}^{18}O$ value of Jurassic biotite granite at Ogryong is higher (+10.21‰) than that of Cretaceous one at Chodun (+8.41‰). The ${\delta}^{13}C$ values of carbonate rocks range from -0.89‰ to 0.68‰ and the ${\delta}^{18}O$ values range from +11.91‰ to + 19.34‰ indicating that these carbonate rocks are of marine origin. However, the ${\delta}^{13}C$ values of skarn calcite and vein calcite are -4.80‰ and -12.92‰, and the ${\delta}^{18}O$ values are +5.56‰ and +10.32‰, respectively, indicating that these calcites are of hydrothermal origin. The ${\delta}^{34}S$ values of sulfide minerals range from +4.4‰ to +8.7‰ suggesting that the sulfurs are of magmatic origin.