• The Journal of the Petrological Society of Korea
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• v.19 no.4
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• pp.269-281
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• 2010

The compiled recent precise age data for the plutonic intrusions of Korean peninsula display that the Jurassic igneous activities occurred on the Yeongnam massif since ca. 200 Ma close to the boundary between Triassic and Jurassic. Since then the igneous activities propagated toward further north through time. The Jurassic igneous activities over the Okcheon belt and its vicinity areas began at about 180 Ma when igneous activities of the Yeongnam massif had been almost over. The igneous activities within the Gyeonggi massif located further north started at somewhat later period ca. 170 Ma. Jurassic igneous activities over the Okcheon belt and its vicinity areas ended a little earlier than the Gyeonggi massif area. Such timing differences upon geographic positions within the Korean peninsula seem to reflect variations in distance to the trench, in the direction of subduction, and/or in subduction angle. Therefore precise understanding of the variations in emplacement ages of Jurassic plutons within Korean peninsula can be a important clue to reconstruct the paleogeography and tectonic environment of the northeast Asia during the Jurassic.

• Ocean Science Journal
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• v.43 no.1
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• pp.39-48
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• 2008

Tritium ($^3H$ or T) has been produced mostly by atmospheric nuclear weapon tests, and entered the ocean in the form of water (HTO). As tritium exists as water itself, it has been regarded as an ideal tool to study the transport of water masses. In April 2001 we collected water samples in the western Japan Basin (WJB) for tritium and helium measurement. The timely sampling provided direct evidence of the bottom water formation, resulting in the drastic increase in tritium concentration from 0.3 TU in 2000 to 0.67 TU in 2001. Considering that the new bottom waters were found mostly in the WJB, it implies that maximum 1% of the whole bottom layer below 2600 m should be replaced with the surface water during the severely cold winter 2000 2001. $^3H-^3He$ age, showing the elapsed time since the water left from the surface, can be used to calculate oxygen utilization rate by dividing AOU by the age. Under the condition of 90% oxygen saturation in the surface water, the integration of OUR in the water column below 200 m yields net oxygen consumption of 12 mol $(O_2)m^{-2}yr^{-1}$, which corresponds to the export production of $99\;g\;C\;m^{-2}yr^{-1}$. This estimate is comparable to a previous estimate based on satellite data and implies that the ratio of export to primary production(f-ratio) is as high as 0.5 in the WJB.

• Journal of the Korean earth science society
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• v.26 no.7
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• pp.674-682
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• 2005

The Samsung mine is located in Jeongsan-myeon, Cheongyang-gun, Chungcheongnam-do, and is produces sericite ores. The purpose of this study is to investigate the geology and mineralogy of sericite one and its host-rock together with the alteration processes and age of sericitization. Geological survey, polarizing microscopy, X-ray powder diffraction, electron microprobe analysis, X-ray fluorescent analysis, differential thermal analysis, and K/Ar isotope study have been employed for this study. The mine area is composed of Precambrian granite-gneiss and mica schist, and also Jurassic biotite granite. Serictization has occured within the granite-gneiss, and is interpreted to be formed by hydrothermal alteration. The sericite was formed by the breakdown of orthoclase, plagioclase, and biotite, respectively. With sericitization intensity increase, $SiO_2\;and\;Na_2O$ contents are decreased, while $Al_2O_3\;and\;K_2O$ increased. The formation age of sericite has been determined to be Jurassic, which corresponds well to the intrusion age of the biotite granite nearby.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1483-1490
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• 2005

This study was written in order to help understanding of visible diagnosis of appearance(形). Visible diagnosis of appearance(形) is a very important factor of diagnosis and a first step of visible diagnosis. appearance(形) is closely connection with spirit(神), so is house of spirit(神). If we make a visible diagnosis of appearance(形), we know the prosperousness of energy and the relative seriousness of an illness. Spirit(神) is understood by appearances and movements of patient, and influenced by seasons, lands, human's relationship and the grade of age. By visible diagnosis of appearance(形), we can conclude existence or nonexistence of spirit(神), As comparing spirit(神) with appearance(形), we can decide good or bad prognoses. One man's own appearance(形) is determined by the five human type(五形人). There are very various points of changing form. As divided into principal groups, there are three main groups, that is, sky(天), earth(地) and man(人). The age and sex belong 治 the factor of sky(天), a direction and configuration of the ground(地形) belong to the factor of earth(地), the five human type(五形人) and white fatness(肥白) and black emaciation(黑瘦) belong to the factor of man(人).

• Journal of the Korean Society of Costume
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• v.5
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• pp.7-11
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• 1981

In the vast extent of time, man and his ancestors have existed on earth about 2,000,000 years. For Near-Man, they knew how to make fire and protected themselves with hairs. Old-Man covered their bodies with the skins of wild animals. New Man improved the quality, the range and ingenuity, so they fabricated clothes with the animal skins. New Man is considered as ancestor of Modern Man. They had spread widely over the earth to take advantage of their surroundings. The next period, New Stone Age was chiefly distinguished by agricultural age. He was now about to make clothes from natural fibers. The two most obvious orgins of clothing are to protect the body against environment and to decorate the body. The forms of clothing were different from the various climates and regions they had settled, for example Yo-po Hyung (Apron), Kwae-po Hung (Sewn garment), Kwan-doo Hyung (Poncho), Chun-kae Hyung (Frontopend garment), Chai-hyung Hyung (Body-conforming shape). Our ancestor had moved from Baikal Lake, Central Asia toward northeast; Shun-tung in China, Manchuria and at last Han Panninsula. Considering our basic costume of ancient times were Yu(jacket), Ko(trousers), Sang(skirt), Po (coat) with the accessories of Kwan (crown), Mo (hat), Dai (belt), Hwa, Eie (footwear), here I conjecture our costume of prehistoric period was Chaihyung Hyung(Body-conforming shape) in the purpose of body covering.

• Journal of Science Education
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• v.32 no.2
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• pp.17-32
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• 2008

The purpose of this study was to analyze the use of the e-learning courseware which is about the properties of earth environmental change. I made these materials using Lectora program, and to have more visual effect, I used movies and animations as much as possible. A lot of movies and pictures are added to help student understand the geographical age. Especially the forms of performance test questions are various, and student can check the answer right after taking test. Because of this, they can get a immediate feedback. In addition, this allows you to adapt yourself to the age of information by using the internet. Every plug-in is already linked together, so you only need to once. Pictures and moving reflections can be edited with ease. I hope this study will provide valuable aid for the education of earth science and a chance to develop better materials.

• Economic and Environmental Geology
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• v.24 no.3
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• pp.277-285
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• 1991

We applied Sm-Nd isotopic system to so-called amphibolites occurring within the Ogcheon group to provide constraints on the age of the metasedimentary rocks and to characterize tectonic environment of basaltic magmatism. An internal mineral isochron age of $677{\pm}91Ma({\sigma})$ was obtained from a coarse-grained, intrusive, amphibolite near Mungyeong. Considering previous studies on the age of the Ogcheon group, we interpret that the isochron represents either early metamorphic or emplacement age. The depositional age of the metasedimentary rocks intruded by the amphibolite would be prior to late Proterozoic. The present study and Cambro-Ordovician fossil evidences of previous workers suggest that both Precambrian and Phanerozoic rocks are present in the Ogcheon group. Positive ${\varepsilon}$ Nd values(+2.4 to +3.5) of four whole rocks indicate mantle origin for the amphibolite. These isotopic data, along with published immobile trace element data of Cluzel et al.(1989), strongly suggest that parental rocks of the amphibolite formed in an intraplate environment rather than in island arc or midocean ridge. The age and tectonic environment of amphibolites in the Ogcheon belt suggest that the basaltic magmatism may be related to the late Proterozoic break-up of a presumed supercontinent, but not to the Triassic(?) collision between North and South China continents.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.473-483
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• 1998

The igneous rocks in the Goseong area are composed of the volcanic rocks (andesitic lapilli tuff and rhyodacite), Bulgugsa granites (Hornblende-biotite granite and two pyroxene granite) and intrusive andesites. In the variation diagrams of the trace and rare earth element contents and elemental ratios as well as the REE patterns, the three igneous rock types show different variational trends and patterns. The geochemical features represent that the igneous rocks in the area were formed from three different magmatic pulses. Two independently carried out Rb-Sr isotope experiments for the Goseong granites show that the whole rock ages and Sr initial ratios of the granites are $66.4{\pm}6.2Ma$, $0.70517{\pm}22(2{\sigma})$ and $71.3{\pm}6.8Ma$, $0.70506{\pm}18(2{\sigma})$, respectively. These results suggest that the granites magma originated from the lower crustal materials of igneous origin intruded into the area during the late Cretaceous period. Masan hornblende-biotite granite emplaced at the vicinity of the Goseong area is very similar to the Goseong granite in its mineral compositions, major, trace and rare earth element contents and patterns. The intruding age (100 Ma) of the Masan granite is order than that of the Geseong granite, however. The similarity of the geochemical natures but the contrast of the intruding ages between the Masan and Goseong granites possibly indicate that the magma generation from the same source materials occurred at a temporal interval of ca. 30 Ma.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.117-135
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• 2013

Orbicular granite gneisses occur as a xenolith within two-mica leucogranites, together with early Paleoproterozoic metasedimentary xenoliths, in Wangjeong-ri, Muju area. The whole-rock chemistries and SHRIMP zircon Pb/U ages of the leucogranites indicate that they are S-type granitoids formed in the continental tectonic setting at $1875{\pm}75$ Ma. The SHRIMP age of monazites from the orbicular granite gneiss gives $1867{\pm}4$ Ma as a metamorphic age which is similar to the intrusion age of the two-mica leucogranite within the error range. The similar ages between zircons and monazites represent that the orbicular granite gneisses formed by metamorphism during the intrusion of the two-mica leucogranite; the metasedimetary xenoliths which sank within the parent magma of leucogranites were metamorphosed into orbicular granite gneisses by thermal metamorphism ($650-740^{\circ}C$, 4-6.5 kbar) due to the heat supplied from surrounding magma. During the thermal metamorphism, the core of orbicular granite gneiss mainly consisting of cordierite formed, and in some orbicular granitic gneisses, the leucocratic melt formed by melting of quartz and plagioclase in the core, squeezed out from core and crystallized around the core forming outer rim. The hydrothermal fluid at the late stage of magma differentiation penetrated into the orbicular granite gneisses resulting pinitization of cordierite into chlorite and sericite. As Muju orbicula granite gneiss was formed from sedimentary rocks, it is more appropriate to be called Muju orbicula granitic gneiss.

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.107-124
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• 2015

The 'Imjin System' (or Rimjin System) was established in 1962 as a new stratigraphic unit separated from the Upper Paleozoic Pyeongan System based on the discovery of brachiopods and echinoderms of possible Devonian age. Subsequent discoveries of the Middle Devonian charophytes confirmed the Devonian age of the system. The Imjin System is distributed in the Imjingang Belt between the Pyongnam Basin and the Gyeonggi Massif, spans from the eastern areas including Cholwon-gun of the Gangwon Province, Gumchon-gun, Phanmun-gun, and Tosan-gun of the Hwanghaebuk Province, to the western areas of Gangryong-gun and Ongjin-gun of the Hwanghaenam Province, and includes the Yeoncheon Group (metamorphic complex) to the south. Unlike the lower Paleozoic strata in the Pyongnam Basin which solely produce marine invertebrate fossils, the Imjin System yields diverse non-marine plant and algal fossils. Brachiopods of the system are similar to those from the Devonian of the South China Block and include taxa endemic to the platform, implying a close paleogeographic affinity to the South China Block. The Imjin System is generally considered as of Middle to Late Devonian in age, although there have been suggestions that the system is of the Middle Devonian to Carboniferous in age. North Korean workers postulated that the Imjin System was deposited in the current geographic position, where the "Imjin Sea" (an extension of the South China Platform) was located during the Devonian. The Imjin System displays strong local variations in stratigraphy and its thickness. It has recently been reported that the strata are repeated and overturned by thrust faults in many exposures. The Yeoncheon Group a southward extension of the Imjin System, also experienced intense tight folding and contractional deformation. Northward decrease in metamorphic grade within the system suggests that the northern part of the Gyeonggi Massif and the Imjingang Belt are probably an extension of the Dabie-Sulu Belt between the South China and Sino-Korean blocks, and the Imjin System is an remnant of accretion resulted from the collision between the two blocks. In order to understand tectonic evolution and Paleozoic paleogeography of eastern Asia, further studies on stratigraphic, sedimentologic and tectonic evolution of the Imjin System involving scientists from the two Koreas are urgently needed.