• Economic and Environmental Geology
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• v.29 no.1
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• pp.25-33
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• 1996

Stable isotopic ratios of the carbonate rocks and chemical compositions of the matrix of pebble bearing phyllitic rocks known as the Hwanggangri Formation, which are in hot debate on their origin such as tillite, debris flow and turbidite, were determined to interpret their depositional environment. Argillaceous matrix of the pebble bearing phyllitic rocks has a high content of CaO (av. 19.5%) and MgO (av. 8.3%), corresponding to calcareous sandy shale. No difference of chemical compositions including trace elements and REE is in the matrices between the Hwanggangri and the Kunjasan Formations. Carbonate rocks from the Okchon zone and outside of the zone range $-2.5{\sim}+6.1$‰ in ${\delta}^{13}C$ and $+5.8{\sim}+25.9$‰ in ${\delta}^{18}O$, indicating normal marine limestone. However, unusally $^{13}C$ enriched carbonate rocks might be deposited in the highly evaporated sedimentary basin. A wide variation of ${\delta}^{18}O$ values is responsible for metamorphism with a $^{18}O$ depleted meteoric water. Isotopic equilibrium temperatures by graphite-calcite geothermometer show a higher metamorphic temperature ($547{\sim}589^{\circ}C$) in the Okchon zone than those ($265{\sim}292^{\circ}C$) in the Samtaesan Formation of the Chosun group. Rhythmic alternation of relatively thin shale with thin limestone in the Kounri Formation is not cherty layer but thin limesilicate bed by metasomatic replacement. Judging from the isotopic and chemical compositions of the carbonate rocks and calcareous matrix of the pebble bearing phyllitic rocks, the Hwangganari Formation was deposited in the shallow marine environment favorable to debris flow.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.6
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• pp.102-114
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• 2009

Urban discourse can be used to create a better living environment through open thinking, understanding and discussion. It raises both physical and social issues surrounding the urban environment. It can encourage the participation of citizen groups and lead the way to develop a community-oriented urban environment through inter-discourse agreement. The urban space of Cheonggye Stream has produced a wide range of urban discourse from 2003 to the present. Discourse regarding the Cheonggye Stream restoration project has been approached by fields including landscape architecture, ecology, urbanism, architecture, politics, and economics, among others. This discourse has reduced a variety of issues and ranges of debate. This study has classified these discussions into related fields and ideological attitudes, analysed their content, and interpreted their meaning. In order to examine the mutual relationships existing among these discourses by different ideological groups, an analytical framework was established byputting classified versions of discourses into a coordinate diagram. The overall topography showing the present status of Korea public awareness regarding the urban environment could therefore be determined. As a result, it was found that the disciplines of landscape architecture took a middle ground between groups with practical and radical ideologies regarding the Cheonggye Stream project and was a mediator for both poles to find a point of contact. However, participatory discourse requires the disciplines of landscape architecture to participate more actively in the discourses on urban environment and take a more active stand corresponding to the zeitgeist and people's sense of public justice.