• Journal of the Korean earth science society
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• v.26 no.2
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• pp.166-171
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• 2005

Fossil legumes of Albizia miokalkora Hu et Chaney (Mimosoideae) were found in the Miocene Duho Formation of the Yeonil Group distributed along the coast of Yeonil Bay in the Pohang area. The legume is flat and long and has 5-7 rounded seeds. The legumes of Albizia miokalkora are rare in the Cenozoic floras of the world and only known to Middle Miocene of East Asia. The fossil Albizia may use one of the important taxa to construct the biogeographic history of East Asia. This discovery is the first record of Albizia from the Neogene strata of Korea.

• The Korean Journal of Ecology
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• v.11 no.3
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• pp.137-144
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• 1988

The use of modern pollen spectra for comparative interpretation of fossil pollen sequence requires the ability to distinguish different vegetation types by their pollen spectra, which may show similarities to fossil assemblages. Tertiary marine and non-marine sediments, the Yeonil Group, of the Yeonil area, Korea, was found thirty-two palynomorphic genera. One of the characteristic features of Yeonil geo-flora is predominance of coniferous trees over shrubs, herbs, and ferns. Miocene deposits of Yeonl area, Korea, ae differentiated with five zones. According to the pollen diagram it can be inferred the climate of the Tertiary Miocene of the Yeonil area, Korea.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1613-1616
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• 2008

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.573-583
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• 2010

A paleobotanical study of the fossil woods has been carried out from the Tertiary Janggi Group, Pohang Basin. Three species belonging to three genera of Ulmus sp., Prunus sp., and Acer sp. were identified from the Lower Coalbearing Formation, and two species of two genera of Taxodioxylon sp. and Fagus hondoensis (Watari) from the Upper Coal-bearing Formation. As our specimens are mostly poorly preserved, it is difficult to give clear specific names, but mostly are all characteristic constitutional elements of the Miocene fossil woods in Korea. The values of mean sensitivity measured from the fossil woods of Lower and Upper Coal-bearing Formations are 0.367 and 0.370 respectively, but they are more than 0.30. Based on the present two data mentioned above, it stands to reason that there were many changes in the water supply to the roots of the woods or having influence to some degree each year because of the seasonal changes in rainfall.

• Journal of the Korean earth science society
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• v.31 no.7
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• pp.691-697
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• 2010

Three legume fossils collected from the Miocene Duho Formation of Yeonil Group in the northern Pohang Beach, Gyeongsangbug-do, Korea were described as Albizia miokalkora Hu and Chaney. This species has only appearing in the Miocene floras of Korea, China and Japan until present. It has wide distribution from warm temperate to subtropical-tropical regions but, the diversity of the species of Albizia is not so high. It is considered that the fossil Albizia miokalkora Hu and Chaney might have adapted to the warm climate such as warm temperate climate and subtropical to tropical climate.

• Journal of the Korean earth science society
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• v.30 no.1
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• pp.10-18
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• 2009

Two fruit fossils of Albizia miokalkora were collected from the Miocene Duho Formation of Yeonil Group in the northern Pohang Beach and Changpodong, Gyeongsangbug-do, Korea. The legume is flat and long and has 7 rounded seeds. Although the legume fossils are preserved as impression, they show their whole shape well. It is considered that the fossil Albizia might have flourished in a warm temperate climate in East Asia. This discovery is the second record of Albizia from the Neogene of Korea.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.50-67
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• 1999

Biostratigraphic and paleoenvironmental analyses are carried out on cutting samples from the Dolgorae wells drilled in the Ulleung basin. The clayey, silty, and sandy sediments of the wells yield various microfossil assemblages of relatively good preservation, among which five fossil groups are reported; a total of 97 foraminiferal species of 66 genera, 19 nannofossil species of 12 genera, 86 ostracod species of 41 genera, 107 diatom species of 44 genera, and 124 dinoflagellate cysts species of 45 genera. Based on microfossils the geologic ages of the Dolgorae wells are dated to be from late Early Miocene to Early Pleistocene. Several biohorizons are defined in Neogene successions by the LOD (Last Ocurrence Datum) and FOD (First Ocurrence Datum) of marker species including G. truncatulinoides (LOD: 1.9 Ma) of foraminifera; C. macintyeri (LOD: 1.64-1.60), G. oceanica (FOD: 1.65 Ma), G. caribbeanica (1.72 Ma), D. brouweri (LOD: 2 Ma), R. pseudoumbilica (LOD: 3.66 Ma), P. lacunosa (FOD: 4.2 Ma) of nannofossils; S. ellipsoideus (LOD: 4 Ma), S. palcacantha (LOD: 10.2), C. giusepei (LOD: 14 Ma) of dinocysts; D. seminae v. fossilis (FOD: 3.7 Ma), T. antiqua (LOD: 1.7 Ma), T. convexa (LOD: 2.4 Ma), N. kamtschatica (LOD: 2.58 Ma), T. oestrupii(FOD: 5.1 Ma) of diatoms. Abundance patterns of microfossils throughout the wells reflect changes in paleoenvironmental and sedimentological settings of the basin in relation to sea-level variations. According to these data the large-cycle and small-cycle changes of transgression and regression phases are observed in terrestrial to marine sediments. This high-resolution sequence biostratigraphy established by various fossil groups enabled more reliable correlation between strata and refined interpretation on deposition systems of the basin. It also proved to provide fundamental and precise informations regarding stratigraphic correlation, tectonic events, basin, and depositional history for hydrocarbon explorations, especially in collaboration with seismic-stratigrahic analyses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.699-707
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• 1995

Eurasian yellow perch (Perca fluviatilis) and American yellow perch (Perca flavescens) are known to be endemic species in Eurasia and North America, respectively. The presence of endemic species on each continent suggests their independent evolutionary history. However, because of the morphological similarity, distribution pattern, and only recent fossil record, their divergence time and speciation of the two Perca species has long been controversial. Here, from the comparison of the entire nucleotide sequences of cytochrome b gene, large genetic divergence between the two Perca species is observed although they are morphologically similar each other. Among 1,140 base pairs, interspecific nucleotide differences are found at 130 sites $(11.4\%)$. The differences varies with codon position, showing 22 sites in the first, 5 sites in the second, and 103 sites in the third codon position. Considering the types of nucleotide changes, transitional differences are much more than transversional differences and its ratio turned out to be 5.19. The estimated divergence time of the two Perca species indicates that they were separated each other approximately in the late Miocene period, which implies the long history of speciation. With comparison of the inferred amino acid sequences, strong structural and functional constraints which seem to be maintained by the highly conservative amino acid residues or protein regions, as found in other taxonomic groups of organisms, are also recognized in the cytochrome b of the fishes examined.

• The Korean Journal of Quaternary Research
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• v.6 no.1
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• pp.1-11
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• 1992

The reconstruction of the vegetational and environmental history of the Korean peninsula by the use of various fossil floral data from the Carboniferous period to the Pre-Holocene is reviewed. Though the oldest plant fossil in Korea (Neuropteris) dates back to the Carboniferous period, the first appearance of many of the present-day floristic genera indeed dates back to the Oligocene (c. 40 to 20 million years B.P.), and includes many thermophilous genera. The presence of thermophilous genera in the Oligocene at up to four degrees north of their present distributional limits implies that the climate of the Oligocene was warmer than that of today. The occurrence of similar thermophilous floristic element at up to six degrees north of their present range during the Middle Miocene suggests a maximum northward expansion of warmth-loving evergreen broadleaved vegetation for, recent Korean vegetation history. The continued occurrence of numerous present-day genera since the Oligocene period indicates a long-term stability of Korean vegetation, along with minor fluctuations within it. The admixture of evergreen coniferous plants and deciduous breadleaved plants, however, indicates a probable temperate climate for much of the Middle Pleistocene. There are couple of evidences which are indicative of an early-stage anthropogenic disturbance of natural vegetation during the Middle Pleistocene of Korea. The presence of cold-episodes during the Upper Pleistocene caused a general expansion of deciduous plants and cryophilous evergreen coniferous, plants. It is likely that the maximum southward expansion of cryophilous arctic-alpine and alpine floras in Korea occured during the penultimate glacial period. The disappearance of some cryophilous genera from 10,000 years B.P. marks the continued climatic amelioration since then, along with minor climatic fluctuations during the Holocene period.

• Journal of the Korean Geographical Society
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• v.30 no.1
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• pp.1-13
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• 1995

One of the oldest fossil of conifers and taxads in the Korean peninsula includes Elatocladus, Ullmannia, Walchia and dates back to the Permian period of the Palaeozoic era. The only conifer which successfully survived since the Cretaceous period is Pinus and still thrives in Korea. The extinction of Miocene conifers, such as Sciadopitys, Taxodiaceae, Metasequoia and Cryptomeria may due to the climatic deteriorations during the late Pleistocene period. However, the cryophilous conifers and taxads, e.g..Pinus, Juniperus, Abies, Picea, Cupressaceae, Larix and Taxus continued to exist from the Miocene to the late Pleistocene and became major vegetational elements in the mountainous areas of Korea. As the temperature ameliorates in the late Holocene period, thermophilous Pinus (Diploxylon) gradually had increased in numbers and became a dominant vegetation in the lowland and montane areas since 2,000 years B.P. in korea. Out of various Korean conifers and taxads, Pinus which surviving since the Cretaceous period of Mesozoic era, ranges spatially from southern coastal area to northern alpine belt of the Korean peninsula. Pinus which contains largest species number in conifers is one of the most well-adapted genus to the Korean environment. The next important conifer Juniperus dates back to the Miocene period of Cenozoic era and continuously maintains speciation and expansion of distributional range. Other major conifers and taxads of Korea include Picea, Abies, Lorix and Taxus. The restriction of distributional range of Cephralotaxus and Tsuga may due to the climatic deterioration during the Pleistocene period of Cenozoic era. The patterns of the temporal and spatial distribution of Korean conifers and taxads may provide invaluable informations for the better understanding of present-day distributional range and ecology.