• Journal of the korean society of oceanography
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• 제32권2호
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• pp.63-68
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• 1997

Stable isotope profiles with fine-scale resolution were constructed from the fossil mollusk shells, Mercernaria mercernaria, obtained from the late Pleistocene transgressive deposits of Gomez Pit, Virginia, USA. Incremental sampling were made along the axis of maximum growth to provide high-resolution ${\delta}^{18}$O and ${\delta}^{13}$C records. The ${\delta}^{18}$O shell profiles exhibit a series of pronounced cycles in the overall amplitude, corresponding to strong seasonal variations in temperature, which is apparently positive environmental variable. Contrasts between the patterns of ${\delta}^{18}$O and ${\delta}^{13}$C profiles reflect the relationship influencing the seasonal carbon cycling in the shallow marine environment. Positive anomalies of the ${\delta}^{13}$C values during the summer were observed to be out of phase with the ${\delta}^{18}$O profile. Such relatively heavier carbon source may be alternated due to seasonal methanogenesis during the summer. A hypothesized methane-based system may be operated in the shallow and marginal marine environment, resulting in a ${\delta}^{13}$C enriched bicarbonate pool, in which the heavier isotope seems to be incorporated to the shell carbonate.

• Molecules and Cells
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• 제21권1호
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• pp.89-103
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• 2006

Population structure was investigated in Reticulitermes speratus populations in the Korean Peninsula and the Japanese Archipelago. All trees derived from analyses of the combined sequence dataset of two mitochondrial genes, COII and COIII, showed that R. speratus populations cluster into two major clades comprising the Korean/southern Japanese populations and the northern Japanese populations. Analysis of population genetic structure showed strong genetic partitioning between populations of the two clades. To understand historical migration routes and current distributions, the phylogeographic history of R. speratus was inferred from intra-/interspecific phylogeny and divergence times estimated between the clades of the phylogenetic tree. The estimated migration route and divergence time of ancestral R. speratus are congruent with recent paleogeographic hypotheses involving land-bridge connections between the Asian continent and the Japanese Archipelago. We suggest that ancestral R. speratus separated into northern and southern Japanese populations after its migration into the Japanese main islands from East China during the early Pleistocene via the East China Sea basin, which may have been exposed during that period. The Korean populations seem to have diverged recently from southern Japanese populations; this may explain the current distribution of R. speratus in the Japanese Arachipelago, and account for why it is restricted to northern areas of the Tokara Strait.

• 헤리티지:역사와 과학
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• 제35권
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• pp.4-27
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• 2002

During the last 10 more years, more than one hundred of Paleolithic sites were found in the most part of the Korena peninsula by very active third generation of Paleolithic archaeologists. It became quite sure that most parts of the peninsula was populated during the late Pleistocene. High concentratin of Paleolithic sites in the Chollanamdo Province will be one of the most important field of paleolithic archaeology along with the sites in the Hantan -Imjin river basin. The begining of Upper Paleolithic is quite likley sometime earlier than 30,000 BP and possibly upto 40,000 BP. Micorlithic technology was probably introduced into the peninsula sometime around 20,000 BP. It is quite striking that the Acheulean-typed stone industry from the Chongokni site could be older than 350,000 BP that was estimated by sedimentation rate on the basis of the interval between two different types of Japanese tephras found at the site. More Acheulean-typed bifaces were found in some sites in the Hantan-Imjin river basin. Tanged point which originally found at the Suyanggae site were found at many Upper Paleolithic sites and was made until quite late period of Upper Paleolithic along with micro-blade.

• 한국지형학회지
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• 제27권2호
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• pp.47-64
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• 2020

The Baengnyeongdo-island, located at the northernmost point of the west coast, has developed several coastal landforms. Although the coastal landforms of Baengnyeongdo-island are widely used as a tourism resource, a lot of academic research has not been conducted. In this study, particle size analysis, XRF, and OSL age dating were performed on the BR sandy deposits to find out the formation of coastal sand dunes on Baengnyeongdo-island. Based on the physicochemical properties, the BR section was divided into three parts; BR-A, BR-B and BR-C. First, about 56ka, which corresponds to the MIS 3, fine sand was deposited and forms the BR-C section. Second, the BR-B which located middle part of BR section, showed reversed age stratigraphy. The BR-B was interpreted as reworked sediments based on sedimentary facies and chemical weathering intensity. And, the BR-A composed of fine and medium sands was formed in middle Holocene. This research has significance in that it finds out the paleo sand dunes formed in Pleistocene. This study can contribute to understanding coastal sand dune development on the west coast.

• 한국지형학회지
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• 제25권4호
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• pp.49-62
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• 2018

This study tries to reveal uplift rates inferred from relative and absolute ages on coastal terrace in the West and South Coasts of South Korea. Uplift rate from relative ages on Pleistocene coastal terrace in the West Coast rangesfrom approximately 0.059 to 0.282 m/ky, while a range of approximately 0.020~0.385 m/ky is calculated from the South Coast, suggesting that the South Coast shows higher rate than the West Coast. Based on absolute ages on coastal terrace during MIS 5 in the South Coast, on the other hand, the uplift rates 1 and 4 have ranges of approximately 0.042~0.062 m/ky and 0.051~0.087 m/ky, respectively, indicating that uplift rate in the South Coast is one-third to one-fourth to that in the East Coast. No research on absolute ages in West Coast terrace and lack of relative and absolute ages in the West and South Coasts are considered as the limit in this study.

• 한국동물학회지
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• 제32권4호
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• pp.374-392
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• 1989

한국산 박쥐류의 계통분류학적 연구의 첫 단계로써, 1985년 10월부터 1987년 7월까지 18장소에서 채집된 한국산 박쥐류 중, 관박쥐과(Rhinolophidae)의 1종과 애기박쥐과 (Vespertilionidae)의 6종에 대하여 외·내부형태 및 상환골의 형태를 이용하여 분류학적인 검토를 하였다. 이들 중에는, 희귀종인 문둥이 박쥐(Eptesicus serotinus brachydigitus)가 포함되어, 본 아종에 대한 상세한 형태학적인 특징을 추가·기재하였다. 또한 현생 한국산 익수류상, 고기후 및 고지리를 고려하여 한국산 소익수류상의 성립과정에 대하여 고찰하였다. 즉, 홍적세의 고기후 및 고지리의 변화에 의해서, 남방계보다 북방계 종류가 풍부한 현재의 익수류상이 성립되었다고 생각된다. As a part of studies on taxonomy and phylogeny of bats inhabiting Korea, a taxonomic review of one rhinolophid and six vespertilionid bats collected at 18 localities during the period from October 1985 to July 1987 was carried out, basing on the external, cranial, dental and humeral morphology. These bats include a rare species, Eptesicus serotinus brachydigitus, the detailed characters of which were described in addition to the original description by Mori (1928b). Further, the Korean microchiropteran faunal succession was described laking into consideration the recent chiropteran fauna, and climatic and geographical changes in the Pleistocene: the recent bat fauna of Korea has become abundant in the north-originating species rather than in the south-originating ones, which is a reverse tendency in the Palearctic continent.

• Animal Systematics, Evolution and Diversity
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• 제40권1호
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• pp.47-67
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• 2024

The bryozoan assemblage from Seogwipo Formation in Jejudo yielded 33 taxa, including seven cyclostomes and 26 cheilostomes. It is the first fossil bryozoans described from the entire Korean peninsula. Five species, Callopora inermis, Tegella horrida, Celleporaria reflexa, Porella rotundirostris, and Rhynchozoon obliquimandibulatum, are new to the Korean bryozoan fauna as both in the Recent and fossil records. Tegella horrida, Celleporella reflexa, Porella donoghueorum, and Leischara subgracilis are notably cold-water species. This suggests that the Seogwipo Formation was primarily deposited in shallow water environment, subject to changesinfluenced by warm-water masses and temporarily impacted by cold currents. Only 33 species from the Seogwipo Formation in Korea, are very poor because the Seogwipo Formation is the only Pleistocene marine deposit in the Korean Peninsula. Eight species previously unknown as fossils worldwide, Tubulipora perforata, Puellina paracaesia, Reginella multipora, Celleporella reflexa, Exochella cryptodontia, Suhius cf. rubescentis, Cheiloporina cf. haddoni, and Jodoella koreensis are found in the Seogwipo Formation. This study is meaningful as it reports the first fossil assemblage of bryozoans from the Korean peninsula.

• 한국해양학회지
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• 제22권3호
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• pp.168-178
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• 1987

태평양지역의 200마일 배타적 경제수역에 주로 분포하는 망간각은 평균 1% 이상의 코발트를 함유하고 있어 해저광물자원으로 높은 개발가치를 가지고 있다. 중앙태평양 한 해저산에서 채취된 망간각의 내부구조와 광물조성에 대한 연구를 통해 망간각 형성된 환경에 따른 성장구조 및 광물성분을 검토하였다. 해양의 높은 산화환경하에서 자생한 수성기원의 버나다이트는 망간각 여러 층내에서 유일한 망 간산화물로 존재하며, 망간각 상`하부에서 버나다이트의 다른 산출 상태는 형성기간 동안 지속적으로 변화한 해양 환경을 암시한다. 망간각의 표층으로부터 약 2cm 깊 이에 존재하는 성장결층과 내부구조의 변화는 마이오세 이후 현세에 이르기까지 고 해양환경에 있었던 일련의 해양변화에서 기인된 것이다.

• ALGAE
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• 제34권2호
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• pp.91-97
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• 2019

Chilean species of marine macroalgae with amphitropical distributions oftentimes result from introductions out of the Northern Hemisphere. This possibility was investigated using haplotype data in an amphitropical red macroalgae present in Chile, Callophyllis variegata. Published sequence records from Canada and the United States were supplemented with new collections from Chile (April 2014-November 2015). Specimens of C. variegata were amplified for the 5′ end of the cytochrome c oxidase subunit I gene (COI-5P) and the full length nuclear internal transcribed spacer region. Haplotype networks and biogeographic distributions were used to infer whether C. variegata was introduced between hemispheres, and several population parameters were estimated using IMa2 analyses. C. variegata displayed a natural amphitropical distribution, with an isolation time of approximately 938 ka between hemispheres. It is hypothesized that contemporary populations of C. variegata were established from a refugial population during the late Pleistocene, and may have crossed the tropics via rafting on buoyant species of kelp or along deep-water refugia coincident with global cooling, representing a rare case of a non-human mediated amphitropical distribution.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.49-56
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• 2012

Genetic variation in the Asian shore crab Hemigrapsus sanguineus was determined from partial mitochondrial DNA (mtDNA) sequences of the cytochrome b (Cytb) gene. Samples included 143 crabs from six localities along three coastlines in South Korea. A nucleotide sequence analysis revealed 38 variable sites in a 470-bp sequence, which defined 37 haplotypes. The haplotypes were not associated geographically and had a shallow genealogy. Pairwise $F_{ST}$ tests and a two-dimensional scaling analysis revealed no significant genetic differentiation among most of the populations. The low pairwise comparison values, but significant genetic differentiation of a northeastern population from all other populations, might have been influenced by a restriction in gene flow caused by hydrographic conditions such as ocean boundaries. The high haplotype diversity, low nucleotide diversity, and time since H. sanguineus expansion in Korean coastal waters indicate rapid population growth and a recent, sudden expansion in the Late Pleistocene.