• Journal of the Korean earth science society
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• v.24 no.6
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• pp.549-557
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• 2003

Surface wave exploration method has many advantages over other conventional exploration methods. Only limited accumulation of the study results has been made due to the recent development of the method. In this study the characteristics of the phase dispersion curves of four sites with different geo-technical properties have been identified. A generalized inversion method was used to obtain the shear wave velocity profiles of the study areas. The shear wave velocity profiles were compared with the columnar sections of the boreholes at the sites. This study shows that the rapid changes in the shear wave velocities are consistent with the changes in the sedimentary or lithologic faces found in the borehole measurements. This implicates that the surface wave exploration method could be used to identify changes in the physical properties of sediments or rocks.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.299-314
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• 1984

The Yeongdo Island in Busan City is a remnant of the latest Cretaceous volcano, and consists geologically of andesites, rhyolite tuff, pelitic and psammitic hornfelses, lapilli rhyodacite tuff of the Yucheon Group, felsite and felsite porphyry of the Bulgugsa intrusives, and Holocene sediments in ascending order. The hornfelses are bound to the Taejongdae Formation. The stratigraphic position of the Formation is determined definitely into the Yucheon Group, thus the geologic age is approximately the same with the volcanic rocks of the Group. The sediments had been thermally metamorphosed to make pelitic and psammitic hornfelses of the albite epidote hornfels facies by the effects of active hydrothermal circulation, vaporization, and hybridization of andesitic solution, or of basification of acidic intrusives. Thus, on occasion, those hornfelses are not used to be distinguished from the andesitic rocks in the southeastern part of the Korean peninsula. The paleocurrent direction determined from several cross-beddings of the Taejongdae Formation is suggested to be from southwest to northeast. Orbicular rocks occur in hornfelsed rhyolite tuff, pelitic- and psammitic-hornfelses, and felsite porphyry at a lot of outcrops in the area of southwestern shoreline of the Yeongdo Island. Orbicules in rhyolite tuff and hornfels in the island might have originated from diffusion processes of metasomatic metamorphism carried out by hydrothermal solution rised from the intrusive adamellite which may be emplaced deeply under the Yeongdo volcanics. Those orbicules are due to metasomatic, secondary, and epigenetic origin. Proto-, multi-shelled, and multi-cored orbicules are described in the orbicular tuff. But multi-cored orbicules are not found in the orbicular fornfels. 250 tuff-orbicules numbered sporadically are in $20,000m^2$ area of the locality of orbicular tuff. About 60 hornfels-orbicules occurred sporadically are in $1,700m^2$ area of the locality of orbicular hornfels in the Taejongdae Formation. Orbicules in felsite porphyry might have originated by diffusion reaction between xenoliths and a quiescent zone in felsite porphyry magma. Those are of igneous, primary, and syngenetic origin.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.534-545
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• 2003

The main purpose of this paper is to describe the granitic regolith and frost creep phenomena in Daegwanryung area in order to demonstrate the relationship of the weathered materials and the surrounding surface, in order to point out that the characteristics of this particular complex of granitic regolith most closely resemble those of soil frost creep phenomena formed elsewhere under periglacial conditions. For this study, the writer has clarified their structure and its associated milieux, with a group of methods and techniques, field survey, micro-morphological analysis, granulometry of weathered materials etc. Such facies of granitic regolith in situ with silty heterometric materials and micas are prone to be deformed by cryo-suction as well as deep freezing. It was probably formed by cryogenic activity, or frost creep in the periglacial climate of a very cold and humid condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.567-575
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• 2017

To understand the geochemical characteristics of Gomso Bay, which features extensive Manila clam, we measured various geochemical parameters, organic matter, and trace metals (Cu, Cd, Pb, Zn, Cr, Hg, As and Fe) of intertidal and subtidal surface sediments in 2011. The surface sediments consisted of sedimentary facies including gravel (0.21%), sand (61.1%), silt (32.1%), and clay (6.5%). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) values in most areas were below sediment quality criteria (COD, $20mg/g{\cdot}dry$; AVS, $0.2mg/g{\cdot}dry$). Trace metals in the surface sediments were below pollution thresholds, except for As (morderately polluted). Sediment quality was evaluated using the trace metal pollution load index (PLI) and ecological risk index (ERI), which showed that sediments were generally not polluted and at low risk; however, values along the outer bay were higher. We expect these results will be valuable for sustainable aquaculture prodution and environmental management in Gomso Bay.

• Journal of the Korean association of regional geographers
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• v.15 no.2
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• pp.192-203
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• 2009

The purpose of this paper is to elucidate the formative processes of depositional landforms in Jiwoo drainage basin which located in the most upstream reach of Namgang River. Through the analysis of morphologic characteristics and sedimentary facies, the formative processes can be summarized as follow: First, the high depositional landforms(Sapyeong, Eungam, Naedongdyttle site) were formed by gelifluction process in the periglacial environment during the last glacial period. And the relative height over river bed of them is getting lower from upper to downstream. The extent of the high depositional landforms is assumed about 1 kilometer downstream far from the confluence of Jiwoo stream and Namgang River. Second, the sediments in the gentle slope at Jangseungbuldle were carried by gelifluction process during the last glacial stage after the deep-weathered bedrock had formed a gentle slope. Third, the high depositional landforms were dissected during warm and humid environment of postglacial stage, and some sediments of them were left in the river bed. Later, as the more upstream high depositional landforms were dissected completely, stream power was getting more than resistance(sediment storage) and the low depositional landforms(Sapyeong, Yongchusa, Deungbangdle site) were formed.

• Ocean and Polar Research
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• v.36 no.4
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• pp.395-405
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• 2014

A 570 cm-long sediment core was retrieved at $9^{\circ}57^{\prime}N$ and $131^{\circ}42^{\prime}W$ in 5,080 m water depth from the northeast equatorial Pacific and its stratigraphy was established with $^{10}Be/^9Be$ and paleomagnetic measurements. Successive AF demagnetization reveals eight geomagnetic field reversals. In the reference geologic time scale, the eight reversal events correspond to an age of about 4.5 Ma. However, $^{10}Be/^9Be$-based age yields 9.5 Ma at a depth of 372 cm. Such a large discrepancy in determined ages is attributed to an extremely low sedimentation rate, 0.4 mm/kyr on average, of the study core and resultant loss or smoothing of geomagnetic fields. The composite age model reveals a wide range in the sedimentation rate - varying from 0.1 to 2.4 mm/kyr. However, the sedimentation rate shows systematic variation depending on sedimentary facies (Unit II and III), which suggests that each lithologic unit has a unique provenance and transport mechanism. At depths of 110-80 cm with a sedimentation rate of about 0.1 mm/kyr, ancient geomagnetic field reversal events of at least a 1.8 Myr time span have not been recorded, which indicates the probable existence of a hiatus in the interval. Such a sedimentary hiatus is observed widely in the deep-sea sediments of the NE equatorial Pacific.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.3 no.1
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• pp.17-21
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• 2007

Alagille syndrome is an autosomal dominant genetic disorder and occurs in approximately 1 in 100,000 live births. Diagnostic criteria was established by Alagille. It is mainly caused by a mutation in the Jagged1 gene. Major clinical features of this syndrome are paucity of intrahepatic bile duct with cholestasis, characteristic facies, cardiac murmur, defects of vertebrae, and embryotoxon. And minor clinical features are mental retardation, renal involvement, growth retardation, other skeletal abnormalities, a high-pitched voice. The surviving prognosis of Alagille syndrome patients depends on the severity of cardiovescular malformation in the early ages of infant. However, with the increasing years, it depends on the severity of the liver disease. Cholestasis causes congenital jaundice, malnutrition and growth retardation. Also, the increase of serum cholesterol level cause xanthoma and pruritus. Even though the severity of these problems are reduce with age, there is cases where there is no way but liver transplantation. For oral features of Alagille syndrome patients, green discoloration of entire dentition, induced by bilirubin infiltration into dentinal tubules, is especially. Also, xanthoma on gingiva and partial hypodontia have been reported. This report is on the oral features of an Alagille syndrome patient who visited to Kyung-Pook University Hospital.

• Journal of the Korean Geographical Society
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• v.32 no.1
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• pp.15-30
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• 1997

This paper concerns the Holocene environmental change with vegetational history and sea-level fluctuation at Ilsan area by the analytical data of pollen, sedimentary facies and $C^14$-dating. The hypothetic palaeogeographic maps of the vegetation cover have been reconstructed with the reference to the periods of pollen zone. The environmental characteristics from the pollen zonation have been summerized as follows. 1)Pollenzone I(3.75~5.75m) showed the period of Alnus-and EMW-dominance. The study area was very humid under the influence of the transgression spreading widely from the rapid sea-level rise during the period(8,000~4,200y.BP). 2)Pollen zone II(5.75~6.35m) has been influenced by the fall of the sea-level and ground water surface. This zone(4,200~2,300y.BP) represented the period of spore~ and NAP-dominance with the increase of Pinus. 3) Pollen zone III(6.35~6.55m) has reflected the influence of the transgression and human interferences together. This zone(2,300~1,800y.BP) represented the period of NAP-dominance. The boundary between Subzone Ilb and Pollen zone III represents the same characteristics as what Weber says Grenzhorizont.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.548-557
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• 2001

Ultramafic rocks in the Yesan talc ore deposits area are unknown age plutonic rocks which intruded PreCambrian Yoogoo gneiss, and were intruded by Jurassic biotite granite, and Cretaceous acidic and mafic dykes. The ultramafic rocks consist mainly of serpentinite with some amphibolite and talc ore body. The serpentinites are divided 5 rock types (S1${\sim}$S5) on the basis of the developed degree of serpentine phenocrysts and layerings. It seems that the original rocks of the serpentinites were co-magmatic peridotites (dunite and pyroxene peridotite). Main serpentinization from the original rocks was occurred during amphibolite facies regional metamorphism in Choongnam area which Yoogoo gneiss was affected. Main steatitization from the serpentinites was hydrothermal alteration by ascended hydrothermal fluid through crush zones.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.626-637
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• 2013

We measured the grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS) and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) of intertidal surface sediment collected from 11 islands (62 stations) in the southern region of Jeollanam Province. The objective of this research was to evaluate the organic matter and trace metals contaminations of sediments from coastal island tidal flats. Surface sediment texture was characterized as follows: mud, sandy silt, muddy sand, and slightly gravelly sand facies. The finer sediments are mainly dominated in the northern part of each island. The concentrations of IL, COD, AVS and some trace metals (Al, Fe, Zn, Cr, Cu, and Hg) were higher in the northwestern part of Wan Island and the area between Gogeum and Sinji Islands, and were associated with relatively finer sediment, as compared to other locations. The concentrations of Mn, Pb, Cd, and As were higher in the northwestern and southeastern parts of Geoguem and Pyungil Islands, but were not correlated with mean grain size. Based on sediment quality guidelines (SQGs), the concentrations of trace metals were lower than the values of effect range low (ERL), used in United States, and threshold effects level (TEL), used in Korea, with exception of As. Similarly, the intertidal sediments were moderately contaminated with As, based on the the enrichment factor (EF) and the geoaccumulation index ($I_{geo}$). The high concentration of As in intertidal sediments from this study region may be due to the input of naturally or artificially contaminated submarine groundwater, contaminated waste from seaweed aquaculture operations and/or land-based seaweed processing facilities. Further studies are needed to identify the sources of As in this study region, and to determine the effects of As contamination on coastal ecosystem.