• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.391-398
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• 1998

To understand the current seismic activity and regional tectonic status in and around Gyeongsang basin, Korea Institute of Geology, Mining, and Materials(KIGAM) has performed the earthquake monitoring around the Gyeongsang basin since early 1980's with portable analog seismic instruments for about two months every year. As a part of POSEIDON project, Korea-Japan joint observation around gyeongsang basin in 1991 and 1992, was performed using by temporary seismic station. KIGAM has been continuously operated nine short-period 3-components digital seismic stations since the end of 1994. During the observation period, 247 earthquakes were analyzed and their magnitude was less than 4.5. In general, we could not find any relationship between seismic activity and known surface geological features. But the epicenters were rather concentrated with NW-SE direction. The most active seismicity was found in Gyeongbuk Gyeongjugun Seokeupri and Hyodongri, and Yeongilgun Janggiri and Guryongpo in land, and in three region along the east coast which are 10km and 30km east off from Gampo and 30km east off from Jongja in offshore.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.367-383
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• 2012

The Gyeongsang Arc is the most notable of the Korea Arc that is composed of several volcanic arcs trending to NE-SW direction in the Korean peninsula. The Hayang Group has many volcanogenic interbeds of lava flows by alkaline or calc-alkaline basaltic volcanisms during early Cretaceous. Late Cretaceous calc-alkaline andesitic and rhyolitic volcanisms reconstructed the Gyeongsang Arc that consist of thick volcanic strata on the Hayang Group in The Gyeongsang Basin. The volcanisms characterize first eruptions of basaltic and andesitic lavas with small pyroclastics, and continue later eruptions of dacitic and rhyolitic ash-fall and voluminous ash-flow with some calderas and then domes and dykes. During the Early Cretaceous (about 120 Ma), oblique subduction of the Izanagi plate to NNW from N direction results in sinistral strike-slip faults to open a pull-apart basin in back-arc area of the Gyeongsang Arc, in which erupted lava flows from generation of magma by a decrease in lithostatic pressure. Therefore the Gyeongsang Basin is interpreted into back-arc basin reconstructed by a continental rifting. Arc volcanism began in about 100 Ma with exaggeration of the back-arc basin in the Gyeongsang, and then changed violently to construct volcanic arcs. During the Late Cretaceous (about 90 Ma), orthogonal subduction of the Izanagi plate to NW from NNW direction ceased development of the basin to prolong violent volcanisms.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.98-100
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• 2005

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2006.11a
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• pp.89-89
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• 2006

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.129-149
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• 2006

Previously published stratigraphic, sedimentologic, paleontologic, paleomagnetic and geophysical data are reviewed to make an understanding on the tectonic evolution of the Cretaceous Gyeongsang (Kyongsang) basin, southeast Korea. A stratigraphic framework and a tectonic model on the formation and deformation of the Gyeongsang Basin are newly proposed on the basis of integration these data with magmatism and mineralization ages in the basin. A newly proposed stratigraphic framework indicates that strata in the basin can be subdivided into five distinct stratigraphic units that represent pre-rifting, syn-rifting, inversion I, II, and III stages. The Gyeongsang Basin was formed initially as a pre-rifting stage due to north-south extension in the Late Jurassic prior to a syn-riftins stage that resulted from east-west extension during the Early Cretaceous. In the Late Cretaceous, the basin was deformed by three-staged sequential deformation of north-south, northwest-southeast, and east-west compressions. The tectonic history of the basin has been largely controlled by the change of motion of the Izanagi Plate from north to northwest during the Cretaceous. In the early Cretaceous, the Izanagi Plate began to subduct northward beneath the Eurasian Plate and caused the left-lateral strike-slip fault systems in the southern part of the peninsula. The left-lateral wrenching of these fault systems was causally linked to development of pull-apart basins, such as the Gyeongsang Basin in the southeastern part of the peninsula. However, northwestward movement of the Izanagi Plate during the Late Cretaceous probably led to the extensive volcanism as well as sequential deformations in the basin. The stratigraphic and tectonic model, which is newly proposed as a result of this study, may be expected to enhancing the efficiency for exploration and exploitation of useful mineral resources in the basin as well as establishing geologic history in the Cretaceous Gyeongsang Basin. Together with the spatial and temporal correlation of the Cretaceous basins in adjacent areas, this stratigraphic and tectonic model provides a new geologic paradigm to delineate the sophisticated tectonic history of East Asia turing the Cretaceous.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.184-185
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• 2003

The Cretaceous magmatism in the Gyeongsang Basin, which intruded into the upper crust or extruded throughout ENE-trending volcanic belts in southern Korea, led to the formation of two contrasting metallogeinic provinces: the Haman-Gunbug-Goseong and the Euiseong. The Haman-Gunbug-Goseong metallogenic province in the southwestern portion of the Gyeongsang Basin consists of dominantly nonmarine sedimentary rocks (e.g., the Sindong and Hayang groups) which are rarely intercalated with andesitic pyroclastics and flows. (omitted)

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.395-399
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• 2009

Radiotelemetry device was surgically implanted in the abdomen of a Eurasian river otter (Lutra lutra). Behaviors of the otter, hospitalized after surgical implantation were also observed. The surgical techniques involved an incision in the paralumbar fossa to introduce a radiotelemetry device into the abdominal cavity. Thirteen behaviors of the otter during hospitalization following abdominal surgery were observed and the time budget of each behavior and the times at which each behavior seems to appear most frequently were measured. This report could provide surgical techniques involving intra-abdominal implantation in otter and basic information associated with otter's behaviors during hospitalization.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.203-208
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• 2005

We have performed magnetotelluric (MT) surveys to investigate the deep crustal structure of Gyeongsang basin. The MT data were collected in the frequency range from 0.00042 to 320Hz along a profile across the Gyeongsang basin, and 2-D inversion was carried out to interpret the geoelectrical structure. We also extracted gravity data around the MT profile from KIGAM database and calculated the density inversion to compare with the geoelectrical structure. The results obtained are good agreement with geological distribution and indicate contrasts of physical properties of sedimentary rock, igneous rock and metamorphic rock.

• The Journal of the Petrological Society of Korea
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• v.7 no.2
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• pp.77-97
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• 1998

We analyzed geochemical and radiogenic isotope data to investigate the genesis and source characteristics of the Onjeongri granite in the northern part of the Gyeongsang Basin. Field observation and K-Ar ages confirm late Cretaceous intrusion (ca. 87 Ma) of the Onjeongri granite. The hornblende geobarometery gives less than 2 kbar for the emplacement pressure of the Onjeongri granite. Geochemical and isotopic compositions suggest that the Onjeongri granite was formed in a relatively immature arc system. $SiO_2$ contents show a negative linear relationship with initial $^{87}Sr/^{86}Sr$ ratios, and an apparent positive correlation with $^{207}Pb/^{204}Pb$ ratios, suggesting an incomplete mixing or assimilation. However, the isotopic data known for any exposed rocks of the study area do not fit as an endmember, implying that the contaminant might reside in the lower crust. A review of published isotopic ages, geochemical, and Sr and Nd isotopic data for the Cretaceous to Tertiary granites in the Gyeongsang Basin indicates the followings. 1) Granitic magmatism in the Gyeongsang Basin were episodic. 2) Granitic rocks in the basin were derived from young (< 0.9 Ga) lower crust, and their isotopic signatures reflect heterogeneous source region. Geochemical and isotopic signatures of granitic rocks in the basin are difficult to explain by upper crustal contamination. 3) Granites in the Gyeongsang Basin have closely related to those in the San in Belt of the Inner Zone of Southwest Japan in terms of age, petrography, and isotopic and geochemical composition. 4) Sr-Nd isotopic signatures of the Onjeongri granite are relatively primitive compared with granitic rocks in the other parts of the Gyeongsang Basin and in the Inner Zone of Southwest Japan.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.14-14
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• 2003