• 한국석유지질학회:학술대회논문집
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• spring
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• pp.1-11
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• 1997

Thirty one samples from Late Cretaceous and Tertiary interval sections (468-783m) of the Kachi-I Well in Block II, Yellow Sea Basin, have been analysed for their terrestrially derived palynofloras. The systematic study of the palynomorphs recovered has yielded one hundred and fifty-five taxa; forty-three species of spores belonging to twenty-eight genera, seventy-seven pollen assignable to forty-three genera, and twenty-seven species assignable to fifteen genera and eight fungal remains. The results of both qualitative and quantitative analysis propose a succession of eight terrestrial palynomorph associations. Seven associations are erected in Late Maastrichtian and one in Early to Middle Miocene. Age determinations are on the basis of palynomorph taxa alone for the all associations. The Late Cretaceous/Tertiary unconformity is recognised at between 603 and 613m, based on the palynological data. The sedimentary basin during the Late Cretaceous seem to be lowland shallow marginal lacustrine with stagnant, mesotrophic conditions. On the other hand, the basin during the Early-Middle Miocene is considered to have been characterised by lowland swamp areas. The palaeoclimatic conditions during the Late Cretaceous are considered to be humid tropical to subtropical, while during the Early to Middle Miocene they are considered to be warm temperate with humid conditions. A comparison of palynomorph assemblages between the present study and the previous studies of Late Cretaceous in Circum-Pacific Northern Hemisphere is made, These assemblages reveal that lower sections (612-783m) of the Kachi-I well belong to the Late Cretaceous Aquilapollenites province of Herngreen and Chlonova (1981) and Srivastava (1981, 1994).

• Economic and Environmental Geology
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• v.36 no.6
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• pp.545-556
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• 2003

Detailed interdisciplinary investigations demonstrate that the Yeongsan River estuarine-filled sediments clearly record important paleoenvironmental changes during the Last Glacial and Holocene. The sediments from 18.9 m(20.5∼l.6m in depth) long core MW-1 are differentiated by changes in sedimentary textures and palynomorph assemblages. Chronology was provided by AMS$^{14}$C dating and regional pollen correlation. Three paleoenvironrnental phases are recognized: (1) The Last Glacial deposits consist mainly of fluvial sediments and paleosols, experienced deposition alternating with pedogenesis. The appearance of the paleosols suggests that the paleoclimate might be cold and humid. (2) The early and middle Holocene phase started abruptly in response to the rapid global climatic warming. and is characterized by abundant marine palynomorphs. (3) The late Holocene is marked by more cool conditions. The paleoenvironmental changes recorded in the sediments coincide not only with local but also with broad-scale, probably global climate changes.

• Journal of the Mineralogical Society of Korea
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• v.26 no.2
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• pp.65-80
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• 2013

Sediment transport mechanism and distribution of organic sediments are elucidated by the study of particle size, mineralogy, organic matters and microfossils of the surface samples collected from seafloor adjacent Dokdo island. Shallow marine sediments are dominated by coarse- grained sediments including gravel and sand, and their sedimentation has mainly been controlled by traction. While the samples collected from oceanic zone are characterized by high contents of fine- grained sediments such as silt and mud in bulk sediments, and the changes of mineral compositions including clay minerals and feldspar, and the fine sediments have been deposited mainly by suspension. The change of organic sedimentary communities is detected between neritic and oceanic zone. Although marine organic matter is predominant in neritic zone, terrestrial organic matter is monopolized according to increasing water depth. This trend is associated with grain size of sediments. The results also suggest that high pollen concentrations in whole organic matters may played an important role in excessive organic carbon in sediment.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.551-564
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• 2012

This study carried out palynological analysis and seismic interpretation to establish a stratigraphic and environmental reconstruction mainly based on fossil palynomorphs and seismic reflection data correlated with the oil exploation well (BP-1) located in the Sora Sub-basin. There were frequent environmental and floral changes due to sea level change in the Sora Sub-basin. The palynomorph assemblages found in the well sediments enabled paleoecological zonation of the well sediment sequence resulting in 4 zones: Ecozone III, Ecozone IV, Ecozone V, Ecozone VI. Index fossils among palynomorphs indicate geological ages of the units within the well ranging from Eocene to Pleistocene, and paleoenvironment varies from freshwater to inner neritic marine. Previous studies suggest that the marine deposits were slightly different in stratigraphic range from well to well. It is considered the difference is credited to geomorphological setting. This study also shows stratigraphic correlation between existing wells and BP-1 well to establishes a standard stratigraphy of the Domi Basin.