• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.1-5
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• 1989

This study was carried out by using laboratory data to calculate Soil Moisture Control Section (SMCS) for medium textured topo-sequential soils derived from porphyry in Milyang area. The soils studied were characterized by loam to silty clay loam, and the moisture content at -1/3 bar in the solum ranged around 21.06% to 32.42%. The moisture contents per centimeter of soil layer within a solum calculated at field capacity (FC) ranged from 0.11cm to 0.19cm. The upper boundaries of SMCS of the soils calculated on the basis of FC as the water content at -1/3 bar, ranged from 16.2cm to 21.2cm and the lower boundaries from 44.4cm to 63.8cm, and the depth of SMCS were from 27.7cm to 42.6cm in the soil profiles. The Bongsan soil on the summit had shallower in the boundaries and narrower in the depth of SMCS than the soils on side-slopes or on valley.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.837-843
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• 2010

This research investigated classification of clay activity degree by different clay mineral components. Based on compositions of different clay and oxide minerals within 390 soil series in Korea, 7 soils were selected to analyze for CEC and specific surface area of clay minerals. As a result, soils were mainly composed with Chlorite originated from sandstone, Smectite originated from Andesite porphyry and combination of Allophane and Ferrihydrite originated from volcanic ash, if the ratio of CEC value to clay content (degree of clay activity) was greater than 0.7. If the degree of clay activity was ranged between 0.3 and 0.7, soils were composed mainly with Kaolin originated from anorthite. Soils with this ratio also was composted with combinations of Kaolin, Illite and Vermiculite originated with river deposits. When the degree of the activity was less than 0.3, soils were commonly red-yellowish color and composed with two different minerals. One type of composition was Kaolin originated from granite and granite gneiss and the soils contained Geothite and Hematite. The other type was composited mainly with Illite and Vermiculite minerals originated from granite. These soils contained Gibbsite, Geothite and Hematite. The degree of clay activity was highly related with CEC and specific surface area. The greater degree of the activity displayed greater values of clay CEC and specific surface area. It is not easy to measure actual quantity and compositions of clay minerals, while the degree of clay activity can be measured from routine soil analyses. As a conclusion, the degree of clay activity may be not just a simple but also powerful tool to estimate physical-chemical properties of soils and to evaluate the soil classification in Korean soils.

• Journal of the Korean earth science society
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• v.39 no.6
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• pp.575-592
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• 2018

This study investigates the formation mechanism of columnar joints at the Sanin Kaigan Geopark in Japan based on its morphology, rock type and igneous structure. Columnar joints distribute to five areas of three prefectures. That is, Kyogasaki, Byobuiwa, Tateiwa and Kyugenkado in Kyotango area of Kyoto prefecture; Genbudo and Kinumaki Shrine in Toyooka City of Hyogo prefecture; Yoroinosode, Takanosushima, Mini-Yoroinosode in Kamicho Town of Hyogo prefecture; Miooshima and Nagasakihana, Shitaara Domon, Kuzakuishi, Moroyose dyke in Shinonsencho Town of Hyogo prefecture; Shirawara dyke in Iwamicho Town in Tottori prefecture. Igneous structures are divided into three types: lava flow, sill and dyke. Lithologies are divided into five types including basalt, andesite, dacite, rhyolite, and quartz porphyry. Lava flow shows colonnade and entablature. However, entablature is not seen in the sills and dykes in the area. Although the polygons of columnar joint vary from tetragon to octagon, hexagon is most frequently found. The width of colonnades ranges from 10cm to 1m, but their size does not correlate with its $SiO_2$ contents. Meanwhile, their size and morphology at single site are comparatively uniform.

• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.71-77
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• 2019

New geochronological data of U-Pb, Re-Os and the lead isotope analysis of the Cu-Mo-Au mineral deposits are reported in the Trapiche and Constancia around Apurimac province, southeastern part of Peru. The measured ages were the first regional pulse of previously reported mineralization age between 28 and 33 Ma. The lead isotopic results indicate two sources of mineralization. The first source is thought to be derived from the upper crust and the second one is thought to be derived from a mixture of the upper crust and the lower crust.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.675-687
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• 2005

The rocks of the five storied stone pagoda in the Jeongrimsaji temple site are 149 materials in total with porphyritic biotite granodiorite. They include pegmatite veinlet, basic xenolith and evenly developed plagioclase porphyry. This stone pagoda has comparably small fracture and cracks which are farmed in the times of rock properties, but surface exfoliation and granular decomposition are in process actively since the rocks are generally weakened from the influence of air contaminants and acid rain. Structural instability of constituting rocks in the 4th roof materials are observed to occur from distortion and tilt. Such instability is judged to threat stability of the upper part of the stone pagoda. Also, chemical weathering is operating even more as the contaminants, ferro-manganese hydroxides eluted from water-rock interaction on the rock surface. Most of the rock surface is covered with yellowish brown, dark black and light gray contaminants, and especially occur in the lower part of the roof rocks on each floor. The roof underpinning rocks are severe in surface pigmentation from manganese hydroxides and light gray contaminants. The surface of rocks lives bacteria. algae, lichen, or moss and diverse productions in colors of light gray, dark Bray and dark green. Grayish white crustose lichen grows thick on the surface with darkly discolored by fungi and algae in the first stage on basement rocks, and weeds grows wild on the upper part of each roof rocks. This stone pagoda must closely observe the movements of the upper part rock materials through minute safety diagnosis and long term monitoring for structural stability. Especially since the surface discoloration of rocks and pigmentation of secondary contaminants are severe, establishment of general restoration and scientific conservation treatment are necessary through more detailed study for this stone pagoda.

• Economic and Environmental Geology
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• v.39 no.3 s.178
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• pp.329-342
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• 2006

The purpose of this study is to determine the geochemical characteristics for the stream sediments in the Konyang area. So we can estimate the environment contamination and understand geochemical disaster. We collect the stream sediments samples by wet sieving along the primary channels and slowly dry the collected samples in the laboratory and grind to pass a 200mesh using an alumina mortar and pestle for chemical analysis. Mineralogy, major, trace and rare earth elements are determined by XRD, XRE, ICP-AES and NAA analysis methods. For geochemical characteristics on the geological groups of stream sediments, the studied area was grouped into quartz porphyry area, sedimentary rock area, anorthosite area and gneiss area. Contents of major elements for the stream sediments in the Konyang area were $SiO_2\;41.86{\sim}76.74\;wt.%,\;Al_{2}O_{3}\;9.92{\sim}30.00\;wt.%,\;Fe_{2}O_{3}\;2.74{\sim}12.68\;wt.%,\;CaO\;0.22{\sim}3.31\;wt.%,\;MgO\;0.34{\sim}3.97\;wt.%,\;K_{2}O\;0.75{\sim}0.93\;wt.%,\;Na_{2}O\;0.25{\sim}1.92\;wt.%,\;TiO_{2}\;0.40{\sim}3.00\;wt.%,\;MnO\;0.03{\sim}0.21\;wt.%,\;P_{2}O_{5}\;0.05{\sim}0.38\;wt.%$. The contents of trace and rare earth elements for the stream sediments were $Cu\;7{\sim}102\;ppm,\;Pb\;15{\sim}47\;ppm,\;Sr\;48{\sim}513\;ppm,\;V\;29{\sim}129\;ppm,\;Zr\;31{\sim}217\;ppm,\;Li\;14{\sim}94\;ppm,\;Co\;5.6{\sim}32.1\;ppm,\;Cr\;23{\sim}259\;ppm,\;Cs\;1.7{\sim}8.7\;ppm,\;Hf\;2.1{\sim}109.0\;ppm,\;Rb\;34{\sim}247\;ppm,\;Sc\;4.5{\sim}21.9\;ppm,\;Zn\;24{\sim}609\;ppm,\;Sb\;0.8{\sim}2.6\;ppm,\;Th\;3{\sim}213\;ppm,\;Ce\;22{\sim}1000\;ppm,\;Eu\;0.7{\sim}5.3\;ppm,\;Yb\;0.6{\sim}6.4\;ppm$. Generally, the contents of $Al_{2}O_{3}\;and\;SiO_2$ had a good relationships with each other in rocks but it had a bad relationships in stream sediments for this study area. The contents of $Fe_{2}O_3$, CaO, MnO and $P_{2}O_{5}$ had a good relationships with major and minor elements in stream sediments of this study area. The contents of Co and V in the stream sediments had a good relationships with other toxic elements.

• Economic and Environmental Geology
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• v.45 no.4
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• pp.385-396
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• 2012

The geochemical high-grade uranium anormal zone has been reported in the Shinbo mine and its eastern areas, Jinan-gun, Jeollabuk-do located in the southwestern part of Ogcheon metamorphic zone, Korea. In this paper is reported the time-relationship between deformation and growth of metamorphic minerals in the eastern area of Shinbo mine, which consists of the Precambrian metasedimentary rocks (quartzite, metapelite, metapsammite) and the age-unknown pegmatite and Cretaceous porphyry which intrude them, and is considered the relative mineralization time on the basis of the previous research's result. The D1 deformation formed the straight-type Si internal foliation which is defined mainly as the arrangement of elongate quartz, biotite, opaque mineral in andalusite porphyroblast. The D2 deformation, which is defined by the microfolding of Si foliation, formed S2 crenulation cleavage. It can be divided into two sub-phases, early crenulation and late crenulation. The former occurs as the curvetype Si foliation in the mantle part of andalusite. The latter occurs as S1-2 composite foliation which warps around the andalusite. The andalusite porphyroblast began to grow under non-deformation condition after the formation of S1 foliation which corresponds to the straight-type Si foliation. It continued to grow before the late crenulation phase. The age-unknown pegmatite intruded after the D2 deformation and grew the fibrous sillimanite which random masks the S1-2 composite foliation. The D3 deformation formed F3 fold which folded the S1-2 composite foliation, D2 crenulation, fibrous sillimanite. It means that the intrusion of pegmatite related to the growth of the fibrous sillimanite took place during the inter-tectonic phase of D2 and D3 deformations. The retrograde metamorphism is recognized by the chloritization of biotite and two-way cleavage lamellae which is parallel to the S1-2 composite foliation and the F3 fold axial surface in the andalusite porphyroblast. It occurred during the D2 late crenulation phase and D3 deformation. In considering of the previous research's result inferring the most likely candidate for the uranium source rock as pegamatite, it indicates that the age-unknown pegmatite intruded during the inter-tectonic phase of D2 and D3 deformations, i.e. during the retrograde metamorphism related to the uplifting of crust, and formed the uranium ore zone around the Shinbo mine.

• Economic and Environmental Geology
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• v.45 no.1
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• pp.31-40
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• 2012

This paper examined the characteristics of ductile and brittle structural elements with detailed mapping by lithofacies classification to clarify the relationship between the geological structure and the geochemical high-grade uranium anormal zone and to provide the basic information on the flow of groundwater in the eastern area of Shinbo mine, Jinan-gun, Jeollabuk-do, Korea. It indicates that this area is mainly composed of Precambrian quartzite, metapelite, metapsammite, which show a zonal distribution of mainly ENE-WSW trend, and age unknown pegmatite and Cretaceous porphyry which intrude them. But the Cretaceous Jinan Group which unconformably covers them, contrary to assumption, could not be observed. The main ductile deformation structures of Precambrian metasedimentary rocks were formed at least through three phases of deformation [ENE striking regional foliation (D1) -> ENE or EW striking crenulation foliation (D2) -> WNW or EW trending open, tight, kink folds (D3)]. The predominant orientation of S1 regional foliation strikes ENE and dips south, being similar to the zonal distribution of Precambrian metasedimentary rocks. Most predominant orientation of high-angled brittle fracture (dip angle ${\geq}45^{\circ}$) [ENE (frequency: 24.3%) > NS (23.9%) > (N)NW (18.8%) > WNW (16.9%) > NE (16.1%) fracture sets in descending frequency order], which is closely related to the flow of groundwater, strikes ENE and dips south. It also agrees with the zonal distribution of metasedimentary rocks and the predominant orientation of S1 regional foliation. The next one strikes NS and dips east or west. Considering the controlling factor of the geochemical uranium anormal zone in the Shinbo mine and its eastern areas from the above structural data. the uranium source rock in these areas might be pegmatite and the geochemical uranium anormal zone in the Sinbo mine area could be formed by an secondary enrichment through the flow of pegmatite aquifer's groundwater into the Sinbo mine area like the previous research's result.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.435-444
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• 1999

The antimony deposits of the Hyundong mine, located in the northeastern part of the Sobaegsan massif, occur as hydrothermal quartz+carbonate veins and stockworks which fill the fault fractures developed in Precambrian metamOlphic rocks (mainly, granitic gneiss). Hydrothermal alteration occurs commonly in the vicinity of mineralized veins and is characterized by sericitization and silicification. A K-Ar age of alteration sericite is 139.2$\pm$ 4.4 Ma, implying the early Cretaceous age of mineralization, possibly in association with intrusion of nearby acidic dikes (mainly, quartz porphyry). The hydrothermal mineralization occurred in five mineralization stages. These are: (I) stage I, characterized by deposition of chalcedonic quartz; (2) stage II, deposition of quartz with base-metal sulfides and stibnite; (3) stage III, deposition of quartz and carbonates (calcite, dolomite, ankerite, rhodochrosite) with various antimony-bearing minerals such as stibnite, polybasite, berthierite, native antimony, gudmundite and ullmannite; (4) stage IV, deposition of calcite with stibnite; and (5) stage V, deposition of barren calcite. Antimony occurs mostly as stibnite within stages II to IV veins, which has various habits including disseminated, veinlets and euhedral coarse crystals. Fluid inclusion studies indicate that hydrothermal mineralization at Hyundong occurred from the fluids with temperature and salinity of $330^{\circ}$C to 120 and 5.3 wI. % equiv. NaCI. The temperature and salinity of ore fluids systematically decreased with elapsed time in the course of mineralization, possibly due to the influx of larger amounts of meteoric groundwater. The deposition of antimony-bearing minerals occurred at low temperatures «$250^{\circ}$C), mainly due to the cooling and dilution of fluids. Based on the evidence of fluid boiling during the early stage II mineralization, the mineralization occurred under low pressure conditions (about 80 bars, corresponding to depths of about 350 m under hydrostatic pressure regime). Thermodynamic considerations of ore . mineral assemblages indicate that antimony deposition also occurred as the results of decreases in temperature and sulfur fugacity of hydrothermal fluids. Calculated sulfur isotope composition of ore fluids ($\delta^{34}S_{\Sigma s}$=5.4 to 7.8$\textperthousand$) indicates an igneous source of sulfur.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.143-150
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• 1993

To gain the basic informations on soil management practices by determination of the differences of soil genetic characteristics and the contents of soil moisture due to slope aspects of hilly land, this study was conducted at 1992 on sweet persimmon orchard soils derived from porphyry in southern of Korea. The results obtained were summarized as follows. The soils studied were belong to fine loamy family. The degree of soil development was greater in the north than other slope aspects and the solum thickness also the same. The soil chemical properties such as pH and exchangeable cations except for potassium were low generally in the orchards studied but the content of organic matter was lack in the summit and south aspect. The contents of Fe oxide and extractable Al were higher in the subsurface than surface. Fe, Al and clay indexes which indicate relative intensity of B horizon development were higher in the side slope than summit and the highest in the north slope. The rate of solum to B horizon was higher as about 1.5 for summit and west aspect which had thiner B horizon thickness compared to other aspect. North and west aspect had certainly more amount of soil water at drought season than other slope aspects and was lower the difference of soil water between the drought and wet seasons. Therfore, the soil management such as erosion control and irrigation at drought season should be practices differently due to slope aspect and soil chararteristics in the sloped land.