• The Korean Journal of Quaternary Research
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• v.12 no.1
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• pp.77-88
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• 1998

한반도의 제4기 지층을 암층서 및 단구층서를 기준으로 전기, 증기 및 후기 플라이 스토신 지층(Ear-ly Middle late Pleistocene Deposits)으로구분할 수 있다. 제 3기와 제4기 의 경계는 고지자기층서 해석에 의하여 한반도에서는 Gauss와 Matuyama chron 경계인 약 2.6Ma를 기준으로 설정할수 있다. 전기 플라이스토신 지층(Early Pleistocene Deposits)은 지형고도상 조구조 운동이 배제된 지역에서는 80m 이하에서의 계곡 사이에서 나타난다. 증 기 플라이스토신 지층(Middle Pleistocene Deposits)은 약0.8Ma부터 약 125ka까지이다. 중기 플라이스토신은 제4기 초깁터 발달하기 시작하였던 주요 계곡들이 현재와 비슷한 형태로 넓 고 깊어지기 시작했던 시기이다. 하천과 해안에는 일련의 단구지형을 잘발달시키지 시작했 고 단구이 형성은 현재보다 해수면이 더 높았던 마지막간빙기까지 계속되었다. 후기 플라이 스토신 지층(late Pleistocene Deposits)은 약 125Ka부터 10Ka까지이며 마지막 간빙기(Last Inter-glacial)와 마지막빙하기(Last Glacial)가 포함된다, 마지막간빙기 동안에는 제 2 하안 및 제 2 해안단구역층이 잘 발달하여 있다 마지막 빙하기 동안에는 해수면의 하강이 극심했 으며 특히 산사면에서 지형경사면을 따라 하부이동된 사면붕적층이 한반도의 전역에 널리 발달했던 시기였다.

• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.271-273
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• 2002

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.173-184
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• 2019

Variations in grain size distribution and clay mineral assemblage are closely related to the sedimentary facies that reflect depositional conditions during the glacial and interglacial periods. Gravity cores BS17-GC15 and BS17-GC04 were collected from the continental shelf and rise in the eastern Bellingshausen Sea during a cruise of the ANA07D Cruise Expedition by the Korea Polar Research Institute in 2017. Core sediments in BS17-GC15 consisted of subglacial diamicton, gravelly muddy sand, and bioturbated diatom-bearing mud from the bottom to the top sediments. Core sediments in BS17-GC04 comprised silty mud with turbidites, brownish structureless mud, laminated mud, and brownish silty bioturbated diatom-bearing mud from the bottom to the top sediments. The clay mineral assemblages in the two core sediments mainly consisted of smectite, chlorite, illite, and kaolinite. The clay mineral contents in core GC15 showed a variation in illite from 28.4 % to 44.5 % in down-core changes. Smectite contents varied from 31.1 % in the glacial period to 20 % in the deglacial period and 25.1 % in the interglacial period. Chlorite and kaolinite contents decreased from 40.5 % in the glacial period to 30.3 % in the interglacial period. The high contents of illite and chlorite indicated a terrigenous detritus supply from the bedrocks of the Antarctic Peninsula. Core GC04 from the continental rise showed a decrease in the average smectite content from 47.2 % in the glacial period to 20.6 % in the interglacial period, while the illite contents increased from the 21.3 % to 43.2 % from the glacial to the interglacial period. The high smectite contents in core GC04 during the glacial period may be supplied from Peter I Island, which has a known smectite-rich sediment contributed by Antarctic Circumpolar Currents. Conversely, the decrease in smectite and increase in chlorite and illite contents during the interglacial period was likely caused by a higher supply of chlorite- and illite-enriched sediment from the eastern Bellingshausen Sea shelf by the southwestward flowing contour current.

• The Korean Journal of Quaternary Research
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• v.6 no.1
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• pp.13-19
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• 1992

To understand the natural environments and human cultures in the Yellow Sea regions, this paper deals especially the climate and sea level fluctuation in the Yellow Sea and its surrounding region in the period of late Pleistocene (125, 000 yr BP) to Holocene. During the glacial maximum (about 15, 000 yr BP to 18, 000 yr BP), the climate might be cold and arid. These arid climate in the Yellow Sea region did make desertization possible. Possible human culture exchanges between China, Korea and Japan might be carried in a easy way, because the entire basin of the Yellow Sea was exposed as land. Paleoshorelines of the Yellow Sea in the period of 10, 000 yr BP, 9, 000 ry BP and 6, 000 yr BP are presented and sea level fluctuation curve from 37, 000 yr BP (late Pleistocene) to present (late Holocene), for the first time, is presented based on a careful reconsideration of existing old data and recent new data.

• Economic and Environmental Geology
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• v.49 no.6
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• pp.417-432
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• 2016

It was firstly revealed in this research that the marine terrace of the Ijin-ri (Bukpyung-myeon, Haenam-gun) was formed during the last interglacial (Marine Isotope Stage 5e; MIS 5e). The marine terrace totally ranging from 4.8 m (asl) to 8.8 m (asl) is subdivided into 4 units; Unit I ranges 4.8-5.3 m, unit II ranges 5.3-6.9 m, unit III ranges 6.9-8.3 m, and unit IV ranges 8.3-8.8 m. Strong evidences that units II and III were formed during MIS5e were obtained based on OSL dating, the physical characterizations such as particle size distribution, magnetic susceptibility and water content, principal element and trace element analyses, and quantitative clay mineral analysis for samples at the 30 cm intervals. The rounded gravels on the marine terrace are regarded to be originated from the clastic materials transported directly from the surrounding mountains toward the marine and abraded in the coastal area, without any fluvial processes. During the warmest period (125k, unit II), the increase in rainfall, along with the rapid rise in sea level, was likely caused the high amount of clastic materials transported to the upper part of the beach. As a result of comparing clay mineral ratios of study site with those derived from sediments of either tidal flats, or the Yellow Sea, it is interpreted that the sediments of study site were influenced from the marine. The results will be used to investigate the hydrological activity and sedimentary environment during the high sea level in the past.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.290-317
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• 2013

The objectives of this study are to investigate the natural heritage and scientific value of various geosites on Udo Island, and to evaluate the sites as natural monuments and as world natural heritage properties. Udo Island includes a variety of geoheritage sites. Various land forms formed during the formation of the Someori Oreum formed by phreatomagmatic eruptions. The essential elements for the formation of Udo Island are the tuff cone, overflowing lava and overlying redeposited tuff sediments. Various coastal land forms are also present. About 6,000 years B.C., when sea-level rose close to its present level due to deglaciation since the Last Glacial Maximum, carbonate sediments have been formed and deposited in shallow marine environment surrounding Udo Island. In particular, the very shallow broad shelf between Udo Island and Jeju Island, less than 20 m in water depth, has provided perfect conditions for the formation of rhodoids. Significant amounts of rhodoids are now forming in this area. Occasional transport of these rhodoids by typhoons has produced unique beach deposits which are entirely composed of rhodoids. Additional features are the Hagosudong Beach with its white carbonate sands, the Geommeole Beach with its black tuffaceous sands and Tolkani Beach with its basalt cobbles and boulders. Near Hagosudong Beach, wind-blown sands in the past produced carbonate sand dunes. On the northern part of the island, special carbonate sediments are present, due to their formation by composite processes such as beach-forming process and transportation by typhoons. The development of several sea caves is another feature of Udo Island, formed by waves and typhoon erosion within tuffaceous sedimentary rocks. In particular, one sea cave found at a depth of 10 m is very special because it indicates past sea-level fluctuations. Shell mounds in Udo Island may well represent the mixed heritage feature on this island. The most valuable geoheritage sites investigated around Udo Isalnd are rhodoid depostis on beaches and in shallow seas, and Someori Oreum composed of volcanoclastic deposits and basalt lava. Beach and shallow marine sediments, composed only of rhodoids, appear to be very rare in the world. Also, the natural heritage value of the Someori Oreum is outstanding, together with other phreatomagmatic tuff cones such as Suwolbong, Songaksan and Yongmeori. Consequently, the rhodoid deposits and the Someori Oreum are worth being nominated for UNESCO World Natural Heritage status. The designation of Someori Oreum as a Natural Monument should be a prerequisite for this procedure.