삼척지역에 분포하는 평안누층군에 대한 고지자기 연구

도성재,Doh, Seong-Jae 대한자원환경지질학회 1995 자원환경지질 Vol.28 No.6

Paleomagnetic data have been obtained from the Upper Carboniferous-Permian Komok and Cheolam Groups which are exposed in the E-W trending Baekunsan syncline comprising the Pyongan Supergroup in eastern Korea. Two ancient components of magnetization are recovered in these groups by detailed thermal demagnetization: a post-folding component and a pre-folding component. The post-folding component $(D/I=54.0/54.6^{\circ},\;{\alpha}_{95}=14.6^{\circ})$ is a magnetic signature of the Oaebo Orogeny and appears to have been confined mainly to Cretaceous Normal Superchron. It has been rotated clockwise since this magnetization has been acquired. The pre-folding components ($D/I=341/-9.2^{\circ},\;{\alpha}_{95}=7.2^{\circ})$, paleopole at $335.7^{\circ}E$, $44.6^{\circ}N$ for Upper Carboniferous; $D/I=358.3/11.5^{\circ},\;{\alpha}_{95}=6.3^{\circ})$, paleopole at $311.9^{\circ}E$, $58.7^{\circ}N$ for Permian) pass fold and reversal tests. These paleopoles correspond only with the contemporaneous poles from the North China Block: they are removed from the poles from the South China Block. If the results of this study are corrected for the clockwise rotation deduced from the prefolding component, the enhanced agreement with North China Block can be achieved. Therefore, a first-order correlation between the Korean Peninsula and North China at least since Upper Paleozoic times is identified in this study.

백운산 향사대에 분포하는 동고층에 대한 고지자기 연구

도성재,Doh, Seong-Jae 대한자원환경지질학회 1993 자원환경지질 Vol.26 No.3

Paleomagnetic data have been obtained from the Lower Triassic Tonggo formation which is exposed in the E-W trending Baekunsan syncline comprising the Pyongan Supergroup in eastern Korea. Two ancient components of magnetization are recovered in this formation by detailed thermal demagnetization: a post-folding component and a pre-folding component The post-folding component ($D/I=58.8/55.5^{\circ}$) is normally magnetized and appears to acquire in the Cretaceous Normal Superchron. It is a magnetic signature of the Daebo Orogeny and has been rotated clockwise since this magnetization has been acquired, in common with the main synclinal axis. The pre-folding component ($D/I=1.1/19.4^{\circ}$, Paleopole at $306.1^{\circ}E$, $63.2^{\circ}N$) passes fold and reversal tests and is inferred to be a post-depositional or early chemical diagenetic remanence of Lower-Middle Triassic age. This paleopole corresponds only with the Lower Triassic poles from the North China Block: it is removed from the contemporary poles from the South China Block. If the result of this study is corrected for the clockwise rotation deduced from the Cretaceous overprint, the enhanced agreement with the Lower Triassic poles from the North China block can be achieved. Therefore, a first order correlation between the Korean Peninsula and North China at least since Lower Triassic times is identified in this study.

의성지역에 분포하는 백악기 지층에 대한 고지자기 연구

도성재,김광호,Doh, Seong-Jae,Kim, Kwang-Ho 대한자원환경지질학회 1994 자원환경지질 Vol.27 No.3

Paleomagnetic and rock-magnetic data of Cretaceous sedimentary and volcanic rocks from the Euiseong area indicate that the stable components of remanence are carried by single and pseudo-single domain magnetite, with the exception of the Shinyangdong Formation which has been remagnetized. The Hayang Group, except for the remagnetized Shinyangdong Formation, yields the mean characteristic direction of $D/I=22.5^{\circ}/57.2^{\circ}$ (${\alpha}_{95}=4.6^{\circ}$, N=14 sites) and the pole position is $72.0^{\circ}N$, $206.4^{\circ}E$ ($dp/dm=4.9^{\circ}/6.7^{\circ}$). The Yucheon Group shows two polarities and the mean characteristic direction of $D/I=351.2^{\circ}/60.5^{\circ}$ (${\alpha}_{95}=11.2^{\circ}$, N= 19 sites) and the pole position is $81.3^{\circ}N$, $79.0^{\circ}E$ ($dp/dm=13.0^{\circ}/17.0^{\circ}$). The mean directions of both the Hayang and the Yucheon Groups are supported by the McElhinny's fold test at the 99% confidence level and that of the Yucheon Group by a reversal test at the 95% confidence level. A magnetostratigraphic correlation between polarities of the study formations and the Geomagnetic Time Scale indicates that the Hayang Group can be correlated to the Cretaceous Long Normal Superchron (CLNS), and the Yucheon Group to the boundary between the CLNS and the Polarity Chron 33R or later boundaries between normal and reverse polarities. Comparison of the paleopoles from this study with those from the surrounding areas both within the Gyeongsang basin and in the northeastern Asia indicates that the study area was not undergone significant tectonic rotations with respect to the other parts of the Gyeongsang basin and that the Korean Peninsula was the part of the single terrane of the northeastern Asia at least since the CLNS. The Yucheon Group can be divided into four sub-groups based on the paleomagnetic data, suggesting that there were at least four times of volcanic activities in the study area.

대자율 이방성과 이의 지질학적 응용

도성재,Doh, Seong-Jae 대한자원환경지질학회 1991 자원환경지질 Vol.24 No.1

Anisotropy of magnetic susceptibility (AMS), directional variation of susceptibility in a sample, indicates the relative magnitude and orientation of preferentially aligned magnetic grains in a rock sample and represents important aspects of rock fabrics. This observation leads to various studies which applied the AMS technique to numerous geological problems, especially sedimentology, petrology, structural geology, and tectonics. Since AMS is, relative to conventional methods of petrofabric measurement, quickly measured, easily interpretated, and providing quantitative data, AMS technique has evolved into a powerful tool for detection of rock fabrics and continues to draw the interest of non-specialists as well as magnetists. This paper represents the theory, techniques, and parameters of the relatively new AMS method for estimating petrofabrics and their various applications.

단양지역에 분포하는 동고층에 대한 고지자기 연구

도성재,박용희,김지연,Doh, Seong-Jae,Park, Yong-Hee,Kim, Ji-Youn 대한자원환경지질학회 1998 자원환경지질 Vol.31 No.1

Paleomagnetic data have been obtained from the Lower Triassic Tonggo Formation which is exposed in Tanyang area comprising the Pyeongan Supergroup in eastern Korea. Mean characteristic direction of the Tonggo Formation is declination/inclination=$121.4^{\circ}/-26.4^{\circ}$ (k=52.7, ${\alpha}_{95}=7.2^{\circ}$, N=9 Sites) and paleopole at longitude/latitude=$30.7^{\circ}E/33.3^{\circ}N$ ($dp/dm=4.2^{\circ}/7.8^{\circ}$). The mean direction passes reversal test and fold test at 99% confidence level. Therefore, it is inferred to be a pre-folding component. The paleopole position of this study is close to the Triassic pole positions of the North China Block; it is far from those of the South China Block. Therefore, a first order correlation between the Korean Peninsula and North China at least since Lower Triassic times is identified in this study.

Stratigraphic and Sedimentological Implications of Rock-magnetic Properties of Marine Sediments from the Northwest Pacific

Seong-Jae Doh(도성재) 대한지질학회 1989 지질학회지 Vol.25 No.2

A Paleomagnetic Study of Sedimentary Rocks from Kyeongsang Supergroup in Milyang Sub-Basin

도성재(Seong-Jae Doh),황창수(Chang-Soo Hwang),김광호(Kwang-Ho Kim) 대한지질학회 1994 지질학회지 Vol.30 No.3

Geochemistry of Cu-Pb-Zn-Ag Deposits from the Euiseong Mineralized Area

지세정,도성재,최선규,이재호,Chi, Se-Jung,Doh, Seong-Jae,Choi, Seon-Gyu,Lee, Jae-Ho The Korean Society of Economic and Environmental G 1989 자원환경지질 Vol.22 No.3

The Cu-Pb-Zn-Ag hydrothermal vein type deposits which comprise the Dongil and Dong-cheogogsan mines occur within the Cretaceous sedimentary rocks in the Euiseong Basin of the southern Korean peninsula. The ore mineralization is contained within three stage(I,II and III) quartz and calcite veins. Ore minerals occur as dominant chalcopyrite, galena, sphalerite, tetrahedrite and Pb, Ag, Sb and Bi-bearing sulfosalts. Stage I ore minerals were deposited between $400^{\circ}C$ and $200^{\circ}C$ from the fluid with moderate salinities(7.0 to 4.5 eq. wt. % NaCl). Evidence of boiling suggests pressure of less than 150 bars during stage I mineralization. This pressure corresponds to maximum depths of 650 m and 1700 m, respectively, assuming lithostatic and hydrostatic loads. The data on mineralogy, temperature and salinity, together with information on the solubility of Cu complex, suggest that Cu deposition is a result of boiling coupled with declining temperature from $350^{\circ}$ to $250^{\circ}C$ or declining log $a_{o_2}$(from -29.8 to -35.9 atm.)and increasing in pH. Pb, Ag, Sb and Bi-bearing sulfosalts were deposited by cooling and dilution at temperature of less than $250^{\circ}C$ from the ore fluid with less than -35.9 atm. of log $a_{o_2}$. 경북 의성 퇴적분지내에는 수개조의 함 Cu-Pb-Zn-Ag 열수석영맥이 주향 N $20^{\circ}-40^{\circ}W$, 경사 $70^{\circ}-80^{\circ}NE$의 단층면을 따라 충진되어 있으며, 맥폭은 1.0m 이하이고, 약 200m 이상 연장되어 있다. 광화작용은 구조운동에 수반되어 3회 (I, II, III기)에 걸쳐 진행되었다. 주 광화시기인 제 I 광화시기에는 주로 황동석, 유비철석, 황철석, 방연석, 섬아연석과 미량의 사면동석 및 함Pb, Ag, Sb, Bi 유염 광물 등이 산출된다. 유체 포유물 연구에 의하면, 제I광화작용시 동(銅)을 위시한 광석 광물은 7.5-4.5wt.% 염상당농도를 갖는 광화유체로부터 초기 $400^{\circ}C$에서 후기 $200^{\circ}C$에 걸쳐 침전되었고, $350^{\circ}C$ 부근에서 광화유체의 비등 현상이 있었음을 확인하였다. $H_2O-NaCl$ 임계곡선에 의해 구한 광화유체의 최대 압력은 150bar이고, 이는 1.7km의 심도에 해당된다. Cu의 침전은 전 유황종(種)의 농도가 $10^{-0.5}-10^{-1.8}M$인 광화유체가 약 $350^{\circ}C$에서 $250^{\circ}C$로 감소되면서 비등작용과 함께 천수유입에 의한 냉각 작용에 의하여, 광화유체 내의 유황, 산소의 분압이 각각 $10^{-8}$, $10^{-30}atm$.에서 $10^{-12}$, $10^{-36}atm$.으로 감소되고, 한편 pH가 증가되어, Cu complex 이온의 농도가 $10^3$에서 10ppm으로 감소되면서 주로 황동석으로 침전되었다. 함 Pb, Ag, Sb, Bi 유염광물은 $250^{\circ}C$ 이하에서 유황과 산소분압이 각각 $10^{-12}$, $10^{-36}atm$. 이하인 광화유체에서 계속되는 천수유입으로 인한 냉각작용과 희석작용에 의해 침전되었다.

Physical Properties and Optical Symmetry of Some Bireflecting Ore Mineral Species

소칠섭,도성재,이경용,So, Chil-Sup,Doh, Seong-Jae,Lee, Kyeong-Yong The Korean Society of Economic and Environmental G 1985 자원환경지질 Vol.18 No.4

본 논문에서는 세계적으로 유명한 대규모의 황화철상(黃化鐵床)에서 산출되는 7종의 이방성(異方性) 광석광물(鑛石鑛物)을 대상으로 물리적(物理的) 특성(特性)을 실험 연구하고, 광물(鑛物) 고유의 타광학성(他光學性), 결정방향(結晶方向)과의 상관 관계를 밝히며, 금속자원 광물의 감정(鑑定)을 위한 자료를 제시하고자 시도되었다. 연구대상 이방성(異方性) 광물(鑛物)(covellite, graphite)은 광물상호간의 white light color의 차이 뿐아니라 동종광물(同種鑛物)내부의 두 편광(偏光)(상광선(常光線), 이상광선(異常光線))의 방향에 따라 동일한 형태이나 큰 정량적 차이(R=약 10%)를 보여주는 spectral profile을 갖는다. 결정방향(結晶方向)에 따라 고찰된 이방성(異方性) 광물(鑛物)(enargite, famatinite)의 반사력(反射力)은 벽개면에 평행한 면에서 항상 높은 값(R=약 5%)을 갖는다. 측정 반사력(反射力)을 이용하여 규명된 연구 광물종의 광학적(光學的) 대칭성(對稱性)은 covellite가 일륜성(一輪性)(+), graphite는 일축성(一軸性)(-)이고, enargite와 famatinite는 이축성(二軸性)(+)이며, 부반사력(復反射力)이 낮은 gratonite의 경우는 결정이 불가능하였다. 표준하중별로 실시된 휘경도(徽硬度)실험에서 이방성광물(異方性鑛物)(enargite, famatinite)의 결정방향은 큰 영향을 미치는데, 즉 벽개면에 평행한 면에서 항상 높은 (HV=> $200kg/mm^2$) 휘경도(徽硬度)값을 보여준다. 모든 실험광물이 각각 특징적인 indentation의 형태를 갖음은 징경도(徵硬度)와 함께 광물감정(鑛物鑑定)에 유용할 것이다. 실험광물이 최소하중에서 항상 불규칙한 휘경도(徽硬度)값을 갖는 것은 관찰에서 기인되는 측정오차로 사료된다. 휘경도(徽硬度)-반사력(反射力)의 상관 관계를 이용한 시험광물의 분류는 Gray-Millman(1962)의 실험결과와 일치된다. 한편 반사도(反射度)의 과장별 측정오차와 그의 제거 방안이 논의되었다. Spectral reflectivity and microhardness were measured quantitatively on polished surfaces of a selection of bireflecting minerals obtained from several well known metallic deposits. Incremental errors are much higher than decremental errors and errors were found to be lowest in the spectral region close to the green wavelength ($544m{\mu}$). The characteristics of the spectral profile are significant in their control of white light color. The covellite and graphite have reflectivity profiles similar in shape for each principal direction, showing noticeable difference in magnitude between the profiles: The spectral reflectivity of covellite parallel to the extraordinary vibration is higher (R$$\simeq_-$$10%) than that parallel to the ordinary vibration and graphite shows opposite feature. Reflectivity of the enargite and famatinite cut parallel to the cleavage plane is always higher (R$$\simeq_-$$5%) than that of the section cut normal. The optical symmetry of 5 bireflecting minerals was determined by noting the variation in reflectivity at $544m{\mu}$. The data indicate that covellite is optically uniaxial positive and graphite is optically uniaxial negative. The Rm values for enargite and famatinite are clearly closer to the minimum value for the mineral ($R_1$) than to the maximum value ($R_2$) : the minerals can be recognized as optically biaxial positive. Enargite and famatinite cut parallel to cleavage have much higher hardness values (HV=> $200kg/mm^2$) than those cut normal to cleavage. Vickers indentations exhibit characteristic features for all the bireflecting mineral species studied. Broad radicle groupings of the mineral species can be made with regard to the reflectivity microhardness numbers.

Interpretation of Subsurface Structure by 2-D Gravity Modeling Study

위수민,도성재,Wee, Soo-Meen,Doh, Seong-Jae The Korean Society of Economic and Environmental G 1991 자원환경지질 Vol.24 No.4

본 연구에서는 북부 미시간지역에 분포하는 세개의 troughes (Marquette, Republic, and Michigan River troughes)가 만나는 지역의 tectonic evolution을 해석하기 위한 stress의 방향 및 변성퇴적암류의 분포를 이해하는데 도움을 주기위하여, 중력탐사를 통하여 연구지역의 기반암구조 및 이를 피복하고 있는 변성퇴적암과의 관계를 해석하였다. 연구지역은 시생대 기반암(Precambrian W)을 원생대의 변성퇴적암이 부정합으로 덮고 있으며, 이들 암석군들은 현저한 밀도의 차이를 보여 본역의 지각구조를 설명하는데 있어서 중력탐사가 효과적이다. $380km^2$에 걸친 연구지역에 340개의 중력기점을 설정하여 측정된 중력은 표준중력 보정과정을 통하여 중력이상도를 작성하였다. Trough내에 퇴적되어 있는 변성퇴적암류를 따라 positive anomaly가 세 trough들의 축을 따라 나타난다. 각 trough들의 지하구조는 Talwani 방법에 의하여 modelling되었으며, 이들의 심도 또한 계산되었다. 그 결과로 Marquette trough는 비대청형으로 남쪽사면에 비하여 북쪽사면이 급경사를 이루고 있다. 세 trough가 합류하는 지점의 기반암구조는 대체로 평평하며, 이것으로 미루어 이 trough들이 거의 동시에 생성되었음을 시사해준다. A gravity survey was conducted in the western Marquette district, Michigan, to delineate the subsurface structure and the relationship of the Proterozoic Marquette Range Supergroup rocks (Precambrian X) and Archean basement (Precambrian W) where the Republic, Michigan River, and Marquette troughs join. In order to accomplish these purposes, three hundred and forty gravity stations were established in the area of $380km^2$. Positive anomalies are associated with the Precambria X, metasedimentary sequence which has a higer density with respect to the Precambrian W, basement rocks. The dominant positive gravity anomalies follow the axes of the three troughs which are filled with Precambrian X rocks. Subsurface structure was modelled by using the Talwani method. Gravity model studies indicate that the Marquette trough is asymetrically shaped and steeply dipping at the north edge except in the eastern part of the study area. The interpretive results obtained from two dimensional model studies suggest that the basement structure of the study area is relatively flat, and that the troughs were formed contemporaneously.