• Tunnel and Underground Space
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• v.19 no.5
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• pp.450-462
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• 2009

To analyze the behavioral characteristics of rocks on indirect tests and uniaxial compressive strength, researchers have investigated 1417 pieces of rock block, which include igneous, metamorphic and sedimentary rocks in Korea. The same behavioral characteristics have been shown in every type of sedimentary rock and in the same species of rock in the case of Brazilian strength application. This suggests that correlations of rocks for geological considerations can lead to high reliability of the experimental results in case of an indirect method.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.23-28
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• 2003

In order to identify plant species and communities characteristic of lithospheric condition, forest vegetations of igneous(mainly granite) and sedimentary(mainly sandstone) areas in Kyungpook province were compared. We collected 108 phytosociological releves from the older forests over 20 years old. 444 vascular plant species and 25 plant communities were identified. Results of Principal Coordinates Analysis (PCA) indicated that lithospheric conditions and human impacts were the most important factors related to the plant community diversity and species richness. In the igneous rock areas net contribution degree (rNCD) of 139 species including Quercus serrata, Q. mongolica, Lindera obtusiloba and Fraxinus sieboldiana increased and those of Carpinus laxiflora and Styrax japonica decreased. In the sedimentary rock areas, to a lesser extent, 96 species including Q. aliena, Zanthoxylum schinifolium, Potentilla fragarioides var. major, Rhus javanica, and Plectranthus japonicus increased, whereas character species of Lindero-Quercion mongolicae such as Q. mongolica, Q. serrata, Rhododendron schlippenbachii, Acer mono and Styrax obassia decreased, and particularily the species Sasa borealis, the Alangium-Zelkova serrata community and the Philadelphus-Fraxinus mandshurica community were absent. The vegetation of sedimentary rock area is characterized as a regional type shaping dwarf pine forests and sparse and light broad-leaved forests.

• Journal of the Korean earth science society
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• v.44 no.4
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• pp.307-317
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• 2023

We investigate the provenance of detrital garnets in Middle-Upper Jurassic sandstone of the Mino terrane, an accretionary complex in Southwest Japan, based on their chemical composition. The garnet grains in the Mino sandstone are mostly Fe-rich (almandine) and slightly Mg-rich (pyrope) species derived from high-grade metamorphic and intermediate to acidic plutonic rocks. The composition and interpreted origin of the garnets are generally consistent with those of metamorphic and igneous rocks of the Yeongnam Massif on the Korean Peninsula, a possible source region suggested in previous studies. In addition, two single grains of chromian spinel, an accessory mineral found in mafic to ultramafic rocks such as mantle peridotite, were found in one of the Mino sandstone samples. This finding suggests the possible presence of mafic to ultramafic rocks in the source area. The results of this study provide complimentary evidence for establishing a comprehensive tectonic and paleogeographical framework for the Mesozoic East Asian continent.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.363-379
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• 2014

The Haenam Pb-Zn skarn deposit is located at the Hwawon peninsula in the southwestern part of the Ogcheon Metamorphic Belt. The deposit is developed along the contact between limestone of the Ogcheon group and Cretaceous quartz porphyry. Petrography of ore samples, chemical composition of skarn and ore minerals, and geochemistry of the related igneous rocks were investigated to understand the characteristics of the skarn mineralization. Skarn zonation consists of garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone, pyroxene+garnet+quartz${\pm}$calcite zone, calcite+pyroxene${\pm}$garnet zone, quartz+calcite${\pm}$pyroxene zone, and calcite${\pm}$chlorite zone in succession toward carbonate rock. Garnet commonly shows zonal texture comprised of andradite and grossular. Pyroxene varies from Mn-hedenbergite to diopside as away from the intrusive rock. Chalcopyrite occurs as major ore mineral near the intrusive rock, and sphalerite and galena tend to increase as going away. Electron probe microanalyses revealed that FeS contents of sphalerite become decreased from 5.17 mole % for garnet${\pm}$pyroxene${\pm}$calcite${\pm}$quartz zone to 2.93 mole %, and to 0.40 mole % for calcite+pyroxene${\pm}$garnet zone, gradually. Ag and Bi contents also decreased from 0.72 wt.% and 1.62 wt.% to <0.01 wt.% and 0.11 wt.%, respectively. Thus, the Haenam deposit shows systematic variation of species and chemical compositions of ore minerals with skarn zoned texture. The related intrusive rock, quartz porphyry, expresses more differentiated characteristics than Zn-skarn deposit of Meinert(1995), and has relatively high$SiO_2$ concentration of 72.76~75.38 wt.% and shows geochemical features classified as calc-alkaline, peraluminous igneous rock and volcanic arc tectonic setting.