• 자원환경지질
• /
• 제28권1호
• /
• pp.9-17
• /
• 1995

The Kamkye Cu-Pb-Zn-Au-Ag deposits occur as quartz veins that filled fault-related fractures of NW system developed in the Cretaceous Gyeongsang basin. Three major stages of mineral deposition are recognized: (1) the stage I associated with wall rock alteration, such as sericite, chlorite, epidote and pyrite, (2) the early stage II of base-metal mineralization such as pyrite, hematite, and small amounts of sphalerite and chalcopyrite. and the middle to late stage II of Cu-As-Sb-Au-Ag-S mineralization, such as sphalerite, chalcopyrite, galena with tetrahedrite, tennantite, pearceite, Pb-Bi-Cu-S system, argentite and electrum. (3) the stage III of supergene mineralization, such as covellite, chalcocite and malachite. K-Ar dating of alteration sericite is a late Cretaceous ($74.0{\pm}1.6Ma$) and it may be associated with granitic activity of nearby biotite granite and quartz porphyry. Fluid inclusion data suggest a complex history of boiling, cooling and dilution of ore fluids. Stage II mineralization occurred at temperatures between 370 to $220^{\circ}C$ from fluids with salinities of 8.4 to 0.9 wt.% NaCl. Early stage II($320^{\circ}C$, 2.0 wt.% NaCl) may be boiled due to repeated fracturing which opened up the hydrothermal system to the land surface, and which resulted in a base-metal sulfide. Whilst the fractures were opened to the surface, mixing of middle-late stage II ore fluids with meteoric waters resulted in deposition of Cu-As-Sb-Au-Ag minerals from low temperature fluids(${\leq}290^{\circ}C$). Boiling of ore fluids may be occured at a pressure of 112 bar and a depth of 412 m. Equilibrium thermodynamic interpretation of sphalerite-tetraherite assemblages in middle stage II indicates that the ore-forming fluid had log fugacities of $S_2$ of -6.6~-9.4 atm.

• 한국가스학회지
• /
• 제18권3호
• /
• pp.20-30
• /
• 2014

비전통가스 자원을 개발하기 위해서는 저류층 암체의 치밀성을 도출하는 물성 분석이 요구된다. 특히, 치밀가스와 같은 비전통자원의 경우, 전통적인 천연가스전과 비교하여 투과도가 특징적으로 낮아서 통상적인 물성 측정 기술을 적용하기에는 한계가 있다. 이에 본 연구에서는 비정상상태에서 저투과성 암체의 물성을 측정하는 압력펄스감소법을 기반으로 실험 장치를 개발하였다. 개발된 기기는 우리나라 경상분지 치밀사암의 물성 분석에 이용되었으며, 각 시료의 투과도와 공극률을 도출하였다. 또한, 실험을 통해 얻은 자료와 이론해 모델 간의 회귀분석 결과 모두 0.96 이상의 상관계수를 나타냈으며, 개발된 장치에 대한 높은 신뢰성을 확인할 수 있었다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2006년도 공동학술대회 논문집
• /
• pp.41-50
• /
• 2006

본 연구에서는 표면파의 군속도 분산 분석을 이용하여 한반도에 설치된 광대역 관측소 사이의 지각 및 상부맨틀의 지진파 속도 구조를 연구하였다. 지진파 잡음의 상호상관기법(Campillo and Paul, 2003; Shapiro et al., 2005)을 이용하여 단주기 표면파의 군속도 분산을 계산하였다. 기존의 잡음 상호상관 기법과는 다르게 지진파 신호를 화이트닝하여 분석에 사용하였다. 그린 함수에서 MFT(multiple filter technique) 방법을 이용하여 0.5 - 20 초 주기의 표면파의 군속도를 계산하였다. 두 관측소 경로에 대하여 얻어진 표면파 군속도 자료를 한반도에 대해 공간적으로 이메이징하기 위하여 표면파 토모그래피 역산을 하였다. 역산 결과 한반도의 남동부에 위치한 경상 분지의 낮은 군속도를 확인할 수 있었다.

• 자원환경지질
• /
• 제16권1호
• /
• pp.11-18
• /
• 1983

Gyeongsang Basin in the southeastern part of the Korean peninsular is characterized by many fault systems. To decipher the geotectonical evolution of the Korean peninsular and marginal basins in her adjacent areas it is prerequisite to understand the spatial distribution pattern and mutual relationships of these fault systems. Because of difficulties in finding any criterion to recognize the faults in field, their extension and mutual relationships in ages are not very clear yet. As an attempt to find geophysical criteria to recognize the fault, geoelectrical resistivity survey was carried out in this study. With the Wenner configuration four resistivity soundings and twenty seven resistivity profilings were done. The electrode distance used was up to 50m. From the results of the resistivity soundings and boring data of earlier groundwater investigations the depth of alluvial and weathered zone was established to be at most 20m in the study area. In the resistivity profiling low resistivity anomaly zones are detected on every traverse, which are interpreted as caused by fractures, fault clays and mylonites in the fault zone. The width of the fault zone amounts to 0.3-1km. By correlating and connecting the negative anomaly zones from traverse to traverse one can determine the trend of th of the faultzone and therefore that of fault itself. The recognized fault trend in this way was $N15^{\circ}-20^{\circ}E$ and this coincides with the direction of the inferred fault line from earlier geological surface mapping. With the help of this characteristical negative anomaly the existance of another $N80^{\circ}W$ trending fault was estabished. This study has shown that geoelectrical resistivity survey can be applied successfully to the problem of tracing fault line insofar as a fault zone has been developed along fault line.

• 자원환경지질
• /
• 제30권3호
• /
• pp.263-275
• /
• 1997

Compound calcrete deposits are recognized from the Dadaepo Formation in Dusong peninsula, Pusan, and their textures, structures, morphology, and stratigraphic distribution are examined. The Dadaepo Formation in study area consists of fluvial plain deposits including floodplain-lake deposits, and the compound calcrete deposits occur above floodplain deposits and below lacustrine deposits. The compound calcrete deposits are composed of nodular to massive (micritic), laminar, nodular, nodular to massive (marly), and marly calcrete deposits. In these calcretes, circumgranular and curved cracks, alveolar structures, fitted peloids, tubular fenestrae with laminar micrite wall (rootlet casts), microstalactic calcite, and tepee structures are observed, which indicates that they are calcic paleosols. Considering their stratigraphic occurrences and pedogenic origin, compound calcrete deposits are interpreted to have formed on distal fluvial plain to palustrine environment by the repetetion of deposition and subsequent calcification due to alternation of lake expansion and contraction. The repetetion of calcrete formation suggests that arid climatic condition was alternated with humid condition in short-term period. Such alternated paleoclimatic condition is similar to those of the Sindong and Hayang groups, and indicates that short-term fluctuations from arid to humid climate were prevailing in overall Gyeongsang Basin. In stratigraphic sense, the compound calcrete deposits can be used as a marker deposit for the correlation of the Dadaepo Formation.

• 자원환경지질
• /
• 제27권4호
• /
• pp.325-333
• /
• 1994

Gold and/or silver mineralization in the southeast province, Korea, occurred in hydrothermal quartz vein that fills fracture zones in Cretaceous volcanic and sedimentary rocks of the Gyeongsang basin or granites and Precambrian gneiss. Most of the gold-silver-bearing veins in the province occur in Hapcheon, Suncheon and Haman-Gunbuk area where they are associated with Cretaceous Bulgugsa granites. On the basis of the Ag/Au ratio on amounts produced and ore grades, mode of occurrence, and associated mineral assemblages, hydrothermal Au-Ag deposits in southeast province, Korea, can be classified as follows: pyrite-type gold deposit (Group IIB, Samjeong and Sangchon deposits), antimony-type gold-silver deposit (Group IV, Gisan and Geochang deposits), and antimony-type silver deposit (Group V, Sanggo, Seweon, Seongju and Gahoe deposits). All of the gold-silver deposits in the province are generally characteristics of the gold-silver or silver-dominant type deposit which contains more silver-bearing minerals than those deposits in central Korea. The gold-silver mineralization in the deposits consist of two generation; the early characterized by gold precipitation and the late represented by silver-rich (as silver-bearing sulfosalts minerals) mineralization. All but one deposit (Samjeong deposit) having relatively lower Au content in electrum values between ${\approx}20$ and ${\approx}50$ atomic %. The mineralogical data on electrum-sphalerite and/or arsenopyrite geothermometry and fluid inclusion data indicate that the gold and silver mineralizations were occurred at temperatures of $190{\sim}280^{\circ}C$ and $150{\sim}180^{\circ}C$, respectively. These suggest that the gold-silver mineralization in the province occurred in the lower temperature and pressure conditions as epithermal-type hydrothermal vein deposit.

• Preventive Nutrition and Food Science
• /
• 제17권2호
• /
• pp.141-151
• /
• 2012

The objectives of this research were to evaluate antioxidant activities and nutritional components, including phenolic acid, catechin, organic acid, sugar, and amino acid, of persimmon juice from persimmons grown in different regions around Korea. Persimmon (Diospyros kaki) exhibits potent antioxidant effects in DPPH, ABTS, reducing power, and FRAP methods of analysis. The levels of nutritional constituents showed significant differences among all the samples. In particular, tartaric acid, glucose, gallic acid, epicatechin gallate and aspartic acid were observed to be the predominant component for each of their general chemical groups, with total average contents of 1876.51 mg/kg, 62.69 g/kg, 12.73 mg/kg, 208.99 mg/kg, and 31.84 mg/100 g, respectively. Interestingly, persimmons from the Hadong region presented the highest sugar (130.60 g/kg), phenolic acid (42.27 mg/kg), and catechin (527.97 mg/kg) contents in comparison with other regional samples. Moreover, this location exhibited the greatest antioxidant activity with highest total phenolic (298.01 mg GAE/kg) and flavonoid (32.11 mg/kg RE) contents. Our results suggest that strong antioxidant activities of persimmons correlate with high phenolic acid and catechin contents, particularly gallic acid and epicatechin gallate. Additionally, these two compounds may be key factors when considering the useful ingredients of persimmon.

• Parasites, Hosts and Diseases
• /
• 제46권3호
• /
• pp.133-137
• /
• 2008

This study was performed to investigate prevalence of clonorchiasis among the inhabitants living in villages along the 4 major rivers, Nakdong-gang (= river), Seomjin-gang, Youngsan-gang, and Guem-gang in southern Korea. From January to December 2006, a total of 24,075 stool samples (1 sample per an inhabitant) were collected in 23 localities and examined by the formalin-ether sedimentation technique. Of the inhabitants examined, 3,441 (14.3%) were found to harbor various types of intestinal parasite eggs, cysts or larvae. Numbers of infected people were 2,661 (11.1%) for Clonorchis sinensis, 431 (1.8%) for heterophyids, 226 (0.9%) for Entamoeba spp., 57 (0.2%) for Giardia lamblia, 30 (0.1%) for Trichuris trichiura, and 18 (0.07%) for echinostomes. Prevalence rates of clonorchiasis according to the river basin were 17.1% in Nakdong-gang, 11.2% in Seomjin-gang, 5.5% in Youngsan-gang and 4.6% in Guem-gang. Of the 2,661 C. sinensis egg-positive cases, 57.7% was male. The present findings suggest that clonorchiasis is still highly prevalent among inhabitants in the riverside areas of southern Korea, and it is necessary to implement a systematic control program in the endemic areas.

• 지질공학
• /
• 제28권4호
• /
• pp.593-603
• /
• 2018

고함량 우라늄 지하수의 대부분은 경기육괴와 옥천대의 쥬라기 화강암 지질에서 그리고 일부는 옥천대의 백악기 화강암 지질에서 산출되며, 영남육괴의 쥬라기 화강암 지질과 경상분지의 백악기 화강암 지질에서는 거의 산출되지 않는다. 경기육괴와 옥천대의 쥬라기 화강암과 옥천대의 백악기 화강암은 근원 마그마내 지각물질의 비율이 높고 고분화된 특성을 보이는데, 이러한 암석-성인적 특성은 고함량 우라늄 지하수가 해당 암상에서 우선적으로 산출되는 지질학적 주요 요인이다. S-type의 과알루미너질의 고분화 암상인 대전지역의 복운모 화강암에서는 높은 U-함량과 낮은 Th/U ratio 그리고 용해성 광물인 우라니나이트가 산출된다. 이러한 특성은 복운모 화강암이 지하수 내 우라늄의 유용한 공급원임을 지시하는 광물-지구화학적 주요 요인이다. 여러 지역의 지질도폭에서 쥬라기의 흑운모 화강암과 복운모 화강암을 서로 구분하지 않고 흑운모 화강암으로 기재한 경우가 많음을 고려하면, 고함량 우라늄 지하수가 산출되는 흑운모 화강암 지질에서도 복운모 화강암의 영향이 있을 것으로 추정된다.

• 환경생물
• /
• 제39권3호
• /
• pp.336-343
• /
• 2021

Fumigation of fruits and vegetables during quarantine and pre-shipment(QPS) treatment should be effective with a shorter fumigation time to minimize phytotoxicity. In this research study, a shorter fumigation time, 2 hours exposure which is shorter than that of the current commercial fumigation procedures using a lower dose of ethyl formate (EF) mixed with phosphine (PH₃) on strawberry was investigated. The reciprocal effect between EF and PH₃ against nymphs and adult Myzus persicae (Sulzer) and Tetranychus urticae (Koch) was evaluated. In addition, L(Ct)₅₀ and L(Ct)₉₉ of EF only and EF mixed with PH₃ were analyzed at 5℃ and 20℃. The synergistic ratio (SR) of L(Ct)₅₀ and L(Ct)₉₉ for the nymph and adult stages of M. persicae were >1.0, which indicated a synergistic effect between EF and PH₃. However, the SR values of L(Ct)₅₀ and L(Ct)₉₉ of the nymph and adult stages of T. urticae were ≤1.0 indicating that there was no synergistic effect between the two fumigants against T. urticae. Our results showed that the reciprocal effect between EF and PH₃ has different effects on M. persicae and T. urticae. This could be attributed to the biological and physical differences between the class Arachnida and Insecta. The synergistic effect between EF and PH₃ against M. persicae within a shorter exposure period and without phytotoxicity on fruits and vegetables will significantly benefit the horticultural industry.