• Economic and Environmental Geology
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• v.51 no.5
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• pp.409-428
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• 2018

Yeongdong area is located on the border zone between Precambrian Yeongnam massif and central southeastern Ogcheon metamorphic belt, in which Cretaceous Yeongdong sedimentary basin exists. Main geology in this area consists of Precambrian Sobaeksan gneiss complex, Mesozoic igneous and sedimentary rocks and Quaternary alluvial deposits. Above this, age-unknown Ogcheon Supergroup, Paleozoic sedimentary rocks and Tertiary granites also occur in small scale in the northwestern part. This study focuses on the link between the various geology and Rn concentrations in groundwater. For this, twenty wells in alluvial/weathered zone and sixty bedrock aquifer wells were used. Groundwater sampling campaigns were twice run at wet season in August 2015 and dry season in March 2016. Some wells placed in alluvial/weathered part of Precambrian metamorphic rocks and Jurassic granite terrains, as well as Cretaceous porphyry, showed elevated Rn concentrations in groundwater. However, detailed geology showed the distinct feature that these high-Rn groundwaters in metamorphic and granitic terrains are definitely related to proximity of aquifer rocks to Cretaceous porphyry in the study area. The deeper wells placed in bedrock aquifer showed that almost the whole groundwaters in biotite gneiss and schist of Sobaeksan gneiss complex and in Cretaceous sedimentary rocks of Yeongdong basin have low level of Rn concentrations. On the other hand, groundwaters occurring in rock types of granitic gneiss or granite gneiss among Sobaeksan gneiss complex have relatively high Rn concentrations. And also, groundwaters occurring in the border zone between Triassic Cheongsan granites and two-mica granites, and in Jurassic granites neighboring Cretaceous porphyry have relatively high Rn concentrations. Therefore, to get probable and meaningful results for the link between Rn concentrations in groundwater and surrounding geology, quite detailed geology including small-scaled dykes or vein zones should be considered. Furthermore, it is necessary to take account of the spatial proximity of well location to igneous rocks associated with some mineralization/hydrothermal alteration zone rather than in-situ geology itself.

• Economic and Environmental Geology
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• v.28 no.2
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• pp.109-121
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• 1995

The hydrothermal vein type deposits which comprise the Kasihan, Jompong and Gempol mineralized areas are primarily copper and zinc deposits, but they are also associated with lead and/or gold mineralization. The deposits occur within the Tertiary sedimentary and volcanic rocks in the Southern Mountain zone of the eastern Java island, Indonesia. Mineralization can be separated into two or three distinct stages (pre-and/or post- ore mineralization stages and main ore mineralization stage) which took place mainly along pre-existing fault breccia zones. The main phase of mineralization (the main ore stage) can be usually classified into three substages (early, middle and late) according to ore mineral assemblages, paragenesis, textures and their chemical compositions. Ore mineralogy and paragenesis of the three areas in the district are different from each other. Pyrite, pyrrhotite (/arsenopyrite), iron-rich (up to 20.5 mole % FeS) sphalerite and (Cu-)Pb-Bi sulfosalts are characteristic of the deposits in the Kasihan (/Jompong) area. On the other hand, pyrite + hematite + magnetite + iron-poor (2.7 to 3.6 mole % FeS) sphalerite assemblage is restricted to the Gempol area. Fluid inclusion data suggest that fluids of the main ore stage evolved from initial high temperatures (near $350^{\circ}C$) to later lower temperatures (near $200^{\circ}C$) with salinities ranging from 0.8 to 10.1 equiv. wt. percent NaCl. Each area represents a separate hydrothermal system: the mineralization at Kasihan and Jompong were largely due to early fluid boiling coupled with later cooling and dilution, whereas the mineralization at Gempol was mainly resulted from cooling and dilution by an influx of cooler meteoric waters. Fluid inclusion evidence of boiling indicates that pressures of ${\geq}95$ to 255 bars (${\geq}95$ bars for the Gempol area: $\approx$ 120 to 170 bars for the Jompong area: $\approx$ 140 to 255 bars for the Kasihan area) during portions of main ore stage mineralization. Equilibrium thermodynamic interpretation indicates that the evolution trends of the temperature versus fS2 variation of ore stage fluids in the Pacitan district follow two fashions: ore fluids at Kasihan and Jompong changed from the pyrite-pyrrhotite sulfidation stage towards pyritehematite- magnetite state, whereas those at Gempol evolved nearly along pyrite-hematite-magnetite reaction curve with decreasing temperature. The sulfur isotope compositions of sulfide minerals are consistent with an igneous source of sulfur with a ${\delta}^{34}S_{{\Sigma}s}$ value of about 3.3 per mil. The oxygen and hydrogen isotopic compositions of the fluids in each area indicate a progressive shift from the dominance of highly exchanged meteoric water at early hydrothermal systems towards an un- or less-exchanged meteoric water at later hydrothermal systems.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.321-328
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• 2003

The epithermal gold and base metal deposit of the Tanggeung district of West Java consists of four major veins(Celak, Cigodobras, Cilangkap and Pasirbedil) with NS to N10$^{\circ}$∼20$^{\circ}$E and N75$^{\circ}$W strikes. The veins occur within fractures cutting the crystal and lithic tuff of Jampang Formation(Oligo-Miocene) in and around the Mt. Subang of the western Java, Indonesia. The ore mineralization is characterized by the occurrence of pyrite, sphalerite, galena, chalcopyrite, and small amounts of bornite and Fe-oxides. Hydrothermal alteration, associated with the mineralization, was dominantly silicified and enveloped by the phyllitic(sericitic), argillic and propylitic alteration containing the disseminated pyrite. Gangue minerals consist of interstratified smectite-illite, chlorite, sericite, and minor kaolinite. The presence of vapor-rich fluid inclusions in quartz veins suggests that boiling occurred locally throughout ore deposition. Fluid inclusion studies suggest that the ore fluid evolved from initial high temperatures(〓34$0^{\circ}C$) to later lower temperatures(〓19$0^{\circ}C$). Salinities range from 0.0 to 8.3 wt percent NaCl equiv. The relatively high increase in salinity(up to 8.3 wt percent NaCl equiv) might be explained by a local boiling and by a participation of magmatic fluids, supported by the sulfur isotope results. Evidence of fluid boiling suggests that the pressure decreased from 200 bars to 120 bars. This corresponds to the depths of approximately 750 to 1,200 m in a hydrothermal system that changed from lithostatic to hydrostatic conditions. Using homogenization temperatures and paragenetic constraints, the calculated $\delta$$^{34}$ S values of $H_2S$ in ore fluid are -0.2 to 1.8 permil close to the 0 permil isotopic value of magmatic sulfur.

• Economic and Environmental Geology
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• v.12 no.2
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• pp.51-73
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• 1979

The zinc-lead deposits at the Yeonhwa I mine were investigated in terms of ore-forming geologic setting, structural style of ore control, geometry of individual orebodies, zoning, paragenesis and chemical composition of skarn minerals, as well as metal grades and ratios of selected orebodies. The Yeonhwa I mine is characterized by a large swarm of chimney type massive orebodies with thin skarn envelopes, boldly developed through a thick sequence of Pungchon Limestone, the overlying Hwajeol Formation, and the underlying Myobong Slate of Cambrian age. Nearly 20 orebodies of similar shape, but of varying size are arranged in a V-shaped pattern with northwest and northeast trends, clearly indicating an outstanding ore control by a conjugate system of fractures with these trends. Important orebodies are the Wolam 1, 2, 3, and 5 orebodies in the west, and the Namsan 1, 2, 3. and 5 orebodies in the east, among others. The Wolam 1 orebody, which was observed from the -360 level through the -240, -120, and 0 levels to the surface outcrops (totaling a vertical height of about 500m), shows a vertical variation in skarn mineralogy, ranging from pyroxene-garnet zone on the lower levels. through pyroxene (without garnet) zone on the intermediate levels, and finally to rhodochrosite vein on the upper levels and surface. Microprobe analyses of pyroxene and garnet on a total of 14 mineral grains revealed that pyroxenes are manganoan salitic in most samples, with downward increase of Fe and Mn, whereas garnets are highly andraditic, containing fractions of subordinate grossular with downward decrease of Fe. This indicates a reverse relationship of Fe-contents between pyroxene and garnet with depth. Ore minerals are major sphalerite, subordinate galena, and minor chalcopyrite. Sulfide gangue minerals include major pyrrhotite, and minor pyrite and marcasite of later age. Two types of variational trends in metal grades and ratios with depth are present on the plots of assay data from the Wolam orebodies: one is a steady upward increase in Pb, Zn, and Pb:Zn ratios, with a terminal decline at the top of orebody: the other is an irregular or sinusoidal change. The former is characteristic of chimney-type orebodies, whereas the latter is of vein· shaped orebodies. The Pb grades show large variations among orebodies and from level to level, whereas the Zn grades are relatively constand or less variable.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.73-84
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• 2010

Gold and silver deposits within the Eunjeok and Sangeun mines are located in Yeongam district, Cheollanamdo-province. They are composed of vein ore bodies infilling the fractures of Cretaceous rhyolitic tuff. The Eunjeok mine have three gold and silver bearing hydrothermal veins which is infilling the fracture of rhyolitic tuff. Major ore minerals within the Eunjeok and Sangeun mines are arsenopyrite, pyrite, chalcopyrite, sphalerite and galena and minor ores are electrum, native silver and argentite. Sericitization is dominant in alteration zone and chloritization and dickitization is minor. Quartz veins in the Eunjeok and Sangeun mine have the similar paragenesis and vein textures such like breccia, crustiform, comb and vuggy morphology indicating the formation of typical epithermal environment. In order to carry out the preliminary feasibility study of mine according to the commodity and elucidate the occurrence features of mineral resources from Eunjeok and Sangeun mine, common commodity (Pb, Zn, Cu, Fe, Mo, W, Au and U), and industrial commodity (In, Re, Ga, Ge, Se, Te, Y, Eu and Sm) for 17 ore specimen were analyzed. It is tentatively thought that there is no exploitable mine for iron, lead, zinc, copper, tungsten and uranium based on the preliminary result. If the reserves are secured through the detailed prospecting in case of molybdenum and silver, it is tentatively thought that there will be exploitable deposits depending on international metal price. If we assume the vein width from 0.25 m to 2 m including alteration zone with the gold grade of 80g/t, it is inferred that the resources amount of the Eunjeok-Sangeun mines range from 6.5 to 65ton. However, as the vein structure of the Eunjeok and Sangeun mines is developed together with alteration zone, it should be estimated to include potential alteration zone in order to yield the average grade. It is needed to carry out more exploration in the near future because the reserves can be flexibly estimated according to the change of average grade considering the alteration zone.

• Economic and Environmental Geology
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• v.15 no.3
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• pp.155-166
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• 1982

Sulfur isotope compositions (${\delta}^{34}S$) of seventy one sulfide minerals from the Shinyemi ore deposits were determined to range from -10.1 to +5.0‰ with a mean value of +2.1‰. These values are roughly comparable to those of various hydrothermal ore deposits in Korea, about +2.0 to +7.0‰ in ${\delta}^{34}S$, suggesting that they are to be same in source of sulfur. The Shinyemi deposits are grouped into two types; the western bedded skarn orebodies and the eastern small pipes and veins. The ${\delta}^{34}S$ values of sulfide minerals from the bedded orebodies (early mineralization) are ranging from -10.1 to +2.5‰, which is relatively wide in range, whereas those of the pipes and veins. (later mineralization) have a narrow range of ${\delta}^{34}S$ values, +2.7 to +5.0‰, regardless of the kind of sulfide minerals. Isotopic temperature obtained from the sphalerite-galena mineral pairs of the New B orebody appeared to be about 400 to $540^{\circ}C$ are reasonably good agreement with the comparable data of skarn mineral assemblages. It is concluded that the west orebodies were formed in earlier stage at higher temperatures than the east orebodies formed later at lower temperatures. Judging from the various data from the present study, the Shinyemi deposits can be defined as a typical contact metasomatic deposit. The source of sulfur in the hydrothermal solutions is considered to be comagmatic with the Shinyemi granodiorite.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.257-268
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• 2003

The Cretaceous magmatism in the Gyeongsang Basin, Korea, led to the formation of two contrasting metallogenic provinces: the Haman-Gunbug-Goseong(-Changwon) (HGGC) and the Euiseong (EU). The mineralization in the HGGC metallogenic province represents copper, gold and iron of porphyry-related deposits that display close relationships in time and space with subvolcanic granitoids. Much of copper-gold-forming events in this province are consistently constrained to the period between ca. 89 and 81 Ma. The hydrothermal systems of copper-gold vein deposits in the HGGC province are associated with ore-forming fluids of high to intermediate temperature (300∼50$0^{\circ}C$) with high salinity (20∼55 equiv. wt. % NaCl). The ore-forming fluids become progressively more diluted by the incorporation of decreased quantities of magmatic water further from the nearby intrusion, suggesting significant input and fluid mixing of a meteoric water component to the magmatic fluids during the late stage of geothermal systems. In contrast, the EU metallogenic province is characterized by polymetallic vein deposits that are consistently constrained to a period of 78∼60 Ma. The geothermal systems of polymetallic vein deposits in the EU province are derived from a narrow range of intermediate temperature (200∼40$0^{\circ}C$) with relatively low salinity(1∼7 equiv. wt.% NaCl). It may represent a mixed fluid of magmatic and meteoric waters. The base-metal mineralization in the Gyeongsang Basin shows a close spatial and temporal distinction between the proximal environment derived from shallow-level granitoids in the southwestern HGGC province and the distal condition derived from volcanic environments in the northwestern EU province.

• Economic and Environmental Geology
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• v.20 no.4
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• pp.273-288
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• 1987

연화(蓮花) 연(鉛) 아연광산(亞鉛鑛山)은 광체(鑛體)의 분포(分布)에 따라 본산지구(本山地區), 동점지구(銅店地區) 및 태백지구(太白地區)로 구분할 수 있다. 태백지구(太白地區)에 대한 본격적인 탐광(探鑛)이 시작되기 전인 1981년 당시, 약 25년 동안 채광작업(採鑛作業)이 진행되어 온 본산지역(本山地域)은 주종광체(主宗鑛體)인 월암(月岩) 및 남산광체(南山鑛體)가 -600m level에서 하한(下限)이 드러남에 따라 광량(鑛量)이 크게 소진(消盡)된 상태였으며, 동점지성(銅店地城)은 상하(上下)의 광황변화(鑛況變化)는 크지 않으나 광체(鑛體)의 규모(規模)가 비교적 작아, 조업(操業)의 안정(安定)을 위해서는 신광화대(新鑛化帶)의 개발(開發)이 시급(時急)한 과제(課題)로 대두되었다. 이에 따라 평천(平川), 태백(太白), 동점역(銅店驛), 방터골, 삼방산광화대(三芳山鑛化帶) 등 연화(蓮花) 전역(全域)에 걸쳐 모암(母岩)의 분포(分布), 지질구조(地質構造), 광징(鑛徵) 등을 검토한 결과 탐광대상(探鑛對象)에서 제외되어 왔던 태백지구(太白地區)가 다음과 같은 점에서 유망(有望)한 탐사후보지(探査候補地)로 부각되었다. 첫째, 지표(地表)에서는 풍촌석회암층(豊村石灰岩層)이 분포(分布)되지 않으나 지질구조(地質構造)를 검토한 결과 -300m level 하부(下部)에서는 이의 전층(全層)이 분포(分布)할 것으로 예상되며, 둘째, 두무동층(斗務洞層) 및 동점규암층내(銅店珪岩層內)에서 발견된 광징(鑛徵)들이 하부(下部)의 풍촌석회암내(豊村石灰岩內)로 연장(延長)되면 부광부(富鑛部)를 이룰 것으로 기대되고, 셋째, 지층(地層)의 경사(傾斜)가 $50^{\circ}$ 이상(以上)인 점, 석영반암(石英斑岩)이 분포(分布)하는 점 등은 광상배태(鑛床胚胎)에 양호(良好)한 조건(條件)이고, 넷째, 본산지구(本山地區)의 월곡(月谷), 월암(月岩), 남산(南山)등 주종광화대(主宗鑛化帶)의 연장부(延長部)인 점, 다섯째, 중앙견갱(中央堅坑)으로부터 약 2km 거리로 탐사단계(探査段階)에 별도의 신규투자(新規投資) 없이 굴진(掘進)이 가능하다는 개발조건상(開發條件上)의 이점(利點)이 있었다. 이에 따라 태백지구(太白地區)에 대한 지표정사(地表精査), 물리탐사(物理探査) 및 지화탐(地化探)을 실시하고, 20여년간 축적된 연화광산(蓮花鑛山)의 지질(地質), 광상자료(鑛床資料)를 정리(整理), 그 특성(特性)을 태백지구(太白地區) 탐사(探査)의 가설(假說)로 적용하여 시추계획(試錐計劃)을 수립, 1982년 구조시추(構造試錐)를 실시한 결과 지질구조(地質構造), 풍촌석회암층(豊村石灰岩層)의 분포(分布) 등이 거의 예상했던 대로 밝혀졌으며 태백(太白) 1호광체(號鑛體)의 일단(一端)이 확인되기에 이르렀다. 1983년(年) 7월(月) 본산지구(本山地區) -600m level에서 태백(太白) 크로스 탐광굴진(探鑛掘進)이 착수되었으며, 1985년에 마침내 갱내(坑內)에서 태백(太白) 1호(號), 2호(號) 광체(鑛體)가 착광(着鑛)되었다. -600m level에서의 태백(太白) 1호광체(號鑛體)의 규모(規模)는 연장(延長) 300m, 평균맥폭(平均脈幅) 8.5m이며, 품위(品位)는 Pb 4.5%, Zn 4.5%, Ag 109g/t이다. 태백광화대(太白鑛化帶)의 지질학적(地質學的) 예상광량(豫想鑛量)은 1,000만(萬)t 이상(以上)이 될 것으로 추정(推定)되며, 현재 -480m level에서 -720m level에 이르기까지 5개 level에서 가행(稼行)되고 있다. 현재 level에서 태백(太白) 1호(號) 광체(鑛體)는 풍촌석회암층(豊村石灰岩層) 및 화절층(花折層)을 모암(母岩)으로 하여 맥상광상(脈狀鑛床)으로 생산(生産)되며, 맥석광물(脈石鑛物)은 능망간석, Mn-방해석(方解石), 방해석(方解石), 석영(石英) 등이고 광석광물(鑛石鑛物)은 섬아연석(閃亞鉛石), 방연석(方鉛石), 황철석(黃鐵石), 자유철석(磁硫鐵石), 유비광석(硫砒鑛石), 황동석(黃銅石), 사면동석(四面銅石), 엘렉트럼 등이다. 태백지구(太自地區)는 광상(鑛床)의 산출상태(産出狀態) 및 지질(地質), 광상학적(鑛床學的) 환경(環境)이 본산지구(本山地區)와 거의 동일(同一)함이 밝혀지고 있다. 태백지구(太白地區)에서는 현재 태백(太白) 1호(號), 2호(號), 3호(號), 5호(號) 및 절골 1호(號), 2호(號) 등 6개 광화대(鑛化帶)에 대한 탐광(探鑛)이 진행되고 있다.

• The Journal of the Petrological Society of Korea
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• v.6 no.2
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• pp.77-85
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• 1997

The Early Proterozoic reworked rock association occurs within the Preacmbrian high grade metamorphic rocks in the area of Daqingshan, Inner Molgolia. In this association, the various large scale ductile deformation belts, form a nappe structure where the foliation steeply dips to north and the lineation ($340^{circ}-30^{\circ}$) plunges at $45^{\circ}55^{\circ}$. This result indicates the subduction/extension with northern part thrusting over the southern part at high angle. The southern subducted microlithon has the characteristics of prograde metamorphism. The northern thrusted microlithon shows the evidence of retrograde metamorphism with decreasing pressure and increasing temperature. The main rock types of Early Proterozoic Moyites are biotite adamellite and syenogranites occurring in the form of small batholiths or stocks and alkali-feldspar granites in veins. The biotite adamellites are progressively contacted with the Archean and Early Proterozoic rocks and contain a great deal of enclaves of metamorphosed rocks, suggesting an anatexis origin. The geochemical characteristics of moyites show the typical features of anatexis granite. At middle to late Early Proterozoic time, the continent-continent collision formed the large scale thrusting and imbrication of Archean basement rocks. According to the mineral assemblage and thermobarometer of Paria et al. (1988) give the following P-T condition : up-faulted block; $700-710^{\circ}C$, 0.72-0.78 Gpa (early stage) and $600^{\circ}C$, 0.44 Gpa (late stage), footwall block; $620^{\circ}C$, 0.8 Gpa (early stage), $620-840^{\circ}C$, 0.64-0.45 Gpa (peak) and $620-630^{\circ}C$, 0.35Gpa (late stage). These results suggest a clockwise P-T-t path (jin et al., 1991, 1994). According to the depth-temperature model in the comperature subduction zone and the experimental data of Wyllie et al. (1983), we propose a tectonic-magmatic-thermal model to account for metamorphism-anatexis of moyite occurring in subduction-shear zone.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.2
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• pp.131-154
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• 2000

Nan Jing(Difficult Classic), as a catechism, describes in detail and deeply the ideas in Nei Jing(Huangdi's Internal Classic). The description of Nan Jing is focused on basic theories including theories about some disease and is excellent in identification and analysis. The contents of Nan Jing are as follows: 1-23 Nan-pulse and pulse condition, 24~29 Nan-channels and collaterals, 30~47 Nan-viscera and bowels(Zang Fu organs), 48~61 Nan-disease, 62~68 Nan-acupuncture points, 69~91 Nan-acupuncture. Especially, diagnosis techniques in Nan Jing make 'Only method of cunkou pulse taking' that is a technique for feeling the pulse widely applied in these days in Oriental medicine clear. Thus, this book adjusts the theory of pulse and pulse condition given in 1~23 Nan of 'The Study of Nan Jing' in order to enhance an understanding about the theory of pulse and pulse condition. The text of 1~23 Nan about pulse lore centers on all pulse of human body interconnected each other and cunkou, both ends of the pulse, and contrasts regular pulse with irregular pulse. 1. 10 Nan describes the theory about five kinds of evils and hardness and softness, and unique pulse condition of each bowels. 2. 13 Nan explains that the relative difficulty of medical treatment is determined by the degree of balance or unbalance among three factors-colors, pulse and pulse condition, flesh shape. 3. 14 Nan divides pulse and pulse condition into slow pulse and rapid pulse, and explains separately abnormality, great loss of semen, death caused by slow pulse, and abnormality, great loss of semen, death caused by rapid pulse. 4. 15 Nan about taut pulse(弦), full pulse(鉤), floating pulse(毛), deep pulse(石脈) describes that pulse and pulse condition differs according to four seasons. Therefore, Nan Jing establishes clearly techniques of feeling the pulse in 'Only method of cunkou pulse taking(獨取寸口)' and advances the theory of Nei Jing. Futhermore, Nan Jing is more valuable in that it suggests unique theory different with Nei Jing.