해안 풍화지형의 기원과 성격 고찰-풍화와지 내의 암분과 암체의 화학조성 분석을 통하여-

김종연 ( Jong Yeon Kim ),양동윤 ( Dong Yun Yang ),김종욱 ( Jong Wook Kim ),신원정 ( Won Jeong Shin ) 한국지형학회 2014 한국지형학회지 Vol.21 No.3

Various weathering pits are formed on the surface of granitic rock mass at coastal area of Korea. Changes in chemical composition of rock mass, characteristic of weathering pit and forming processes are not clear yet. Chemical characters of weathering pit and rock are analyzed in this study. Especially, the samples were collected from the summit part of the hill which was a part of weathering front, rock wall where the weathering pits(tafoni) are formed and rock meals which deposited at the bottom of weathering pit by granular disintegration from the inside walls of tafoni. Samples were analyzed with XRD and XRF method. The mean value of chemical alteration index(CIA) is found highest from the samples of rock meal while the lowest value found from the top of the hill. The chemical composition of the samples from the top of the hill suggests that these samples have experienced not only removal of specific material by chemical weathering but also re-crystalization or deposition by evaporation of water contains Ca and Na. Quartzite and feldspar are found as dominant materials of rock meal, however gypsum, anhydrite and other clay minerals, like illite and kaolinite, are also been identified. So it is concluded that the rock meal of the study area could be originated from the material formed by chemical weathering. Meanwhile, the weathered material might be removed by granular disintegration caused by freeze and thaw cycle of infiltrated water from snow and expansion of gypsum.

해안 암체와 내륙 암체부의 풍화 와지 사이의 암석 강도 차이에 대한 연구

김종연 ( Jong Yeon Kim ) 한국지형학회 2015 한국지형학회지 Vol.22 No.4

The chemical composition of samples from abandoned cliff and coastal rocks at Munam, Gosung, Gangwon province are analysed. Weathering pits are found at the top and surface of abandoned cliff and these forms are inactive in terms of active physical and chemical weathering. So these forms can be regarded as relict forms rather than active. The tafoni and weathering pits are found from the coastal rocks which are actively being weathered and eroded by sea water and splash. The rebound values are measured at 5 points at and around the abandoned cliff with Schmidt hammer. The results show that the coastal rock has higher rebound values than abandoned cliff. It can be assumed that coastal rock is composed with more resistant rock than abandoned rock cliff. Weathering intensity of each samples can be compared with various weathering indices which can be calculated using chemical composition. In this study, the CIA, most frequently used index in geomorphological literatures, showed only weak difference between the samples. The CIA value of the coastal rock is lower than those of abandoned cliff. However, the difference between two groups is very small. PIA shows similar pattern while the WIP and CPA show similar patterns with larger differences. In the case of WIP, the value of coastal rock is highest and cliff and rock meal are follows. It means the coastal rock is most fresh in terms of chemical weathering while the rock meal is severely weathered. This pattern shows good match with rock rebound values. It is assumed that this pattern is not result of current weathering and weathered material removal processes which is most active near of the sea. It can be concluded that the abandoned cliff had experienced similar weathering environment to coastal rock. After it was abandoned, weathered part of the cliff experienced relatively slow erosion processes and preserve the weathered materials, while weathered part of coastal rock is eroded continuously by sea water and relatively fresh parts are exposed to surface. This results are support the result from previous study from the coast of Yellow sea.

강원 북부 해안 화강암 구릉에 발달한 풍화 와지의 특성과 암석 강도에 대한 연구

김종연 ( Jong Yeon Kim ) 한국지형학회 2013 한국지형학회지 Vol.20 No.2

Most of studies on the weathering pits or tafoni in Korea have been focused on the morphology and spatial distribution of those microforms. Only limited number of researches analized the physical and chemical characteristics of the rocks in relation to forming processes. Rock strength of the bedrock and form of the weathering pit or tafoni on the granite hill on the coast of Munam-ri, Gosung-gun, Gangwon Province are measured in this study. Most of weathering pits or tafoni are found from the low altitude area near of mean sea level. Slope angle of the area where most weathering forms are found are steeper than other parts. For the relatively gentle slopes, weathering pit or bock basin features are dominant and it is assumed that it was evolved from the tafoni or alveoli which have cover and visor. Collapsing of the cover of tafoni or alveoli changed to rock basin. The floor of the weathering pit showed higher rebound value with Schmidt hammer. Weathering forms on the steeper slope have cover and visor which is characteristic of tafoni. The compartments are formed along joint and those changed to the undulated part of wall of tafoni as a result of coalescence of two or more tafoni. Inner wall of tafone has lower rebound values than those of outside of the tafoni.

아야진 구릉에 분포하는 풍화대와 토양의 특성에 대한 연구

김종연 ( Jong Yeon Kim ) 한국사진지리학회 2015 한국사진지리학회지 Vol.25 No.4

Rock coast and coastal hill at the Ayajin, Goseong, Gangwon province are investigated to provide information on characteristics and forming processes of landscape of granite coastal area. In addition, chemical analysis and OSL age estimation are performed to surface material of the coastal hill. The linear depressions and circular depression which are formed by rock weathering are found from the rock surface of the coast. The linear depression are formed by the weathering along the joint and removal processes of weathered material. The circular depressions are regarded as modified gnamma which is formed by weathering, as those are found from the area where the joints sets not cross and abraded features are not observed. The large rounded rocks which are the modified corestones are found from the surface of the rock platform. It can be concluded that rock coast of this area are weathering-origin landforms which are rocks are exposed weathering front by the processes removal of weathered material rather erosional forms which are eroded by sea water. The samples from the hill of saprolite near of the coast are analysed for chemical composition. The CIA values of samples from the ridge are about 70 which are chemically weathered but far from soil. The soil samples of seaward slope showed over 80 CIA values. It can be proposed that soil which are severely weathered part are removed and sprolite are exposed. Reddish brown soil layer of 20cm in thickness which covers in-situ weathered are found. The layer from the ridge which including rounded pebbles showed 0.38±0.06 ka burial age while slope layers of seaward slope showed 0.29±0.04 ka burial age. The origin of these sediments should be investigated in future.

기반암의 물리 화학적 특성과 산지 풍화 지형 발달과의 관계에 대한 연구1) -강원도 삼척시 쉰움산을 사례로-

김종연 ( Kim Jong Yeon ) 한국사진지리학회 2017 한국사진지리학회지 Vol.27 No.2

There are more than 250 weathering pits at the top of the Suinumsan (mountain), located in Samcheok, Gangwon province. Previous researches have distinguished the pits according to their geometrical aspects and formation process. In this study, the landscape of the top (SU07∼SU13) and mid-slope of mountain (Su02∼06) are investigated. In order to compare the characteristics of rock strength and chemical composition affecting pit formation, XRF analysis and Schmidt hammer rebound test were adapted. In the field survey, linear depressions (groove) and circular depressions (gnamma) were found in the middle of the slope. The scale were smaller and development level were lower than those of the mountain top. Also, forming process of the circular pits were similar to the portholes. There was no difference in the rebound strength between two sites. However, there is a difference in rebound strength within each site, which seems to be related to the characteristics of horizontal and vertical cracks developed at each site. Based on this, it seems that there is no direct relationship between rebound strength and pit development. The chemical composition also showed no difference between the top and the midpoint of the slope and the chemical weathering index was not affected by weathering as a whole. The chemical composition also showed a difference in each point. The correlation between rock strength and chemical composition was investigated. There was a direct correlation between the two variables, but there was statistically significant correlation between the content of Si and the content of Al. However, there was no significant correlation with CIA. These results should be reviewed together with the validity of the relevant indicators through further studies in the future.

해양에 유출된 유류의 풍화에 따른 변성 특성 평가 및 지표

전치완,박상원,김강연,전호석 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

유출된 오일의 해양환경에서 풍화에 따른 분해정도 및 변성과정에 대하여 논하였다. 주변 환경에 따라 독특한 변성을 나타내는 생체표지물들을 선정하여 이들의 주어진 환경에서의 변성 특성 및 변화된 정도를 파악함으로써 풍화의 진행 상태와 나아가 오염된 유류의 감쇄 정도를 파악하고자 하였다. 특정적(specific) 방법으로 특정성분 또는 특정성분 그룹에 대한 변성과정과 풍화의 진척도를 평가하기 위한 다양한 지표를 제시하였으며, 비특정적(non-specific) 방법으로 유출유의 전체적인 형태변화와 감쇄 정도 등에 대하여 고찰하였다.