• Title/Summary/Keyword: BEDROCK

Search Result 513, Processing Time 0.018 seconds

Physical Properties of Volcanic Rocks in Jeju-Ulleung Area as Aggregates (제주도 및 울릉도에서 산출되는 화산암의 골재로서의 물성 특징)

  • Byoung-Woon You;Chul-Seoung Baek;Kye-Young Joo
    • Economic and Environmental Geology
    • /
    • v.57 no.2
    • /
    • pp.205-217
    • /
    • 2024
  • This study evaluated the physical characteristics and quality of volcanic rocks distributed in the Jeju Island-Ulleung Island area as aggregate resources. The main rocks in the Jeju Island area include conglomerate, volcanic rock, and volcanic rock. Conglomerate is composed of yellow-red or gray heterogeneous sedimentary rock, conglomerate, and encapsulated conglomerate in a state between lavas. Volcanic rocks are classified according to their chemical composition into basalt, trachybasalt, basaltic trachytic andesite, trachytic andesite, and trachyte. By stratigraphy, from bottom to top, Seogwipo Formation, trachyte andesite, trachybasalt (I), basalt (I), trachybasalt (II), basalt (II), trachybasalt (III, IV), trachyte, trachybasalt (V, VI), basalt (III), and trachybasalt (VII, VIII). The bedrock of the Ulleung Island is composed of basalt, trachyte, trachytic basalt, and trachytic andesite, and some phonolite and tuffaceous clastic volcanic sedimentary rock. Aggregate quality evaluation factors of these rocks included soundness, resistance to abrasion, absorption rate, absolute dry density and alkali aggregate reactivity. Most volcanic rock quality results in the study area were found to satisfy aggregate quality standards, and differences in physical properties and quality were observed depending on the area. Resistance to abrasion and absolute dry density have similar distribution ranges, but Ulleung Island showed better soundness and Jeju Island showed better absorption rate. Overall, Jeju Island showed better quality as aggregate. In addition, the alkaline aggregate reactivity test results showed that harmless aggregates existed in both area, but Ulleungdo volcanic rock was found to be more advantageous than Jeju Island volcanic rock. Aggregate quality testing is typically performed simply for each gravel, but even similar rocks can vary depending on their geological origin and mineral composition. Therefore, when evaluating and analyzing aggregate resources, it will be possible to use them more efficiently if the petrological-mineralological research is performed together.

Distribution Characteristics of Land and River Aggregate Resources in Yeongam Area by Deposition Period (영암지역 육상 및 하천 골재의 퇴적 시기별 분포 특성)

  • Jin Cheul Kim;Sei Sun Hong;Jin-Young Lee;Ju Yong Kim
    • Economic and Environmental Geology
    • /
    • v.57 no.2
    • /
    • pp.243-251
    • /
    • 2024
  • In this study, a surface geological survey was first conducted to investigate aggregate resources in the Yeongam area of Jeollanam-do, and a drilling survey was conducted in the lower part of the surface, which was difficult to identify through a surface geological survey, to determine the spatial distribution of aggregates. Drilling sites were selected considering the topographical development and Quaternary alluvium characteristics of the study area, and river aggregate drilling surveys were conducted at a total of 5 points and land aggregate drilling surveys were conducted at a total of 28 points. Borehole core sediments were classified into seven sedimentary units to determine whether they could be used as aggregates, and optically stimulated luminescence dating was performed on representative boreholes to measure the depositional period for each sedimentary unit. As a result of the study, most of the Yeongam area had a very wide river basin, so it was estimated that there would be a large amount of aggregate, but the amount of aggregate was evaluated to be very small compared to other cities and counties. Most of the unconsolidated sedimentary layers in the Yeongam area are composed of blue-grey marine clay with a vertical thickness of more than 10 m. The sand-gravel layer corresponding to the aggregate section is distributed in the lower part of the marine clay, thinly covering the bedrock weathering zone. This is because the amount of aggregates themselves is small and most of the aggregates are distributed at a depth of 10 m below the surface, which is currently difficult to develop, so the possibility of developing aggregates is evaluated to be very low. As a result of dating, it can be seen that the blue-grey marine clay layer is an intertidal sedimentary layer formed as the sea level rose rapidly about 10,000 years ago. The deposition process continued from 10,000 years ago to the present, and as a result, a very thick clay layer was deposited. This clay layer was formed very dominantly for about 6,000 to 8,000 years, and the sand-gravel layer in the section where aggregates deposited in the Pleistocene period can exist was measured to have been deposited at about 13.0 to 19.0 ka, and about 50 ka, showing that it was deposited as paleo-fluvial deposits before the marine transgression process.

Characteristic on the Layout and Semantic Interpretation of Chungryu-Gugok, Dongaksan Mountain, Gokseong (곡성 동악산 청류구곡(淸流九曲)의 형태 및 의미론적 특성)

  • Rho, Jae-Hyun;Shin, Sang-Sup;Huh, Joon;Lee, Jung-Han;Han, Sang-Yub
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.32 no.4
    • /
    • pp.24-36
    • /
    • 2014
  • The result of the research conducted for the purpose of investigating the semantic value and the layout of the Cheongryu Gugok of Dorimsa Valley, which exhibits a high level of completeness and scenic preservation value among the three gugoks distributed in the area around Mt. Dongak of Gogseong is as follows.4) The area around Cheongryu Gugok shows a case where the gugok culture, which has been enjoyed as a model of the Neo-Confucianism culture and bedrock scenery, such as waterfall, riverside, pond, and flatland, following the beautiful valley, has been actually substituted, and is an outstanding scenery site as stated in a local map of Gokseong-hyeon in 1872 as "Samnam Jeil Amban Gyeryu Cheongryu-dong(三南第一巖盤溪流 淸流洞: Cheongryu-dong, the best rock mooring in the Samnam area)." Cheongryu Gugok, which is differentiated through the seasonal scenery and epigrams established on both land route and waterway, was probably established by the lead of Sun-tae Jeong(丁舜泰, ?~1916) and Byeong-sun Cho(曺秉順, 1876~1921) before 1916 during the Japanese colonization period. However, based on the fact that a number of Janggugiso of ancient sages, such as political activists, Buddhist leaders, and Neo-Confucian scholars, have been established, it is presumed to have been utilized as a hermit site and scenery site visited by masters from long ago. Cheongryu Gugok, which is formed on the rock floor of the bed rock of Dorimsa Valley, is formed in a total length of 1.2km and average gok(曲) length of 149m on a mountain type stream, which appears to be shorter compared to other gugoks in Korea. The rock writings of the three gugoks in Mt. Dongak, such as Cheongryu Gugok, which was the only one verified in the Jeonnam area, total 165 in number, which is determined to be the assembly place for the highest number of rock writings in the nation. In particular, a result of analyzing the rock writings in Cheongryu Gugok totaling 112 places showed 49pieces(43.8%) with the meaning of 'moral training' in epigram, 21pieces (18.8%) of human life, 16pieces(14.2%) of seasonal scenery, and 12pieces(10.6%) of Janggugiso such as Jangguchur, and the ratio occupied by poem verses appeared to be six cases(3.6%). Sweyeonmun(鎖烟門), which was the first gok of land route, and Jesiinganbyeolyucheon(除是人間別有天) which was the ninth gok of the waterway, corresponds to the Hongdanyeonse(虹斷烟鎖) of the first gok and Jesiinganbyeolyucheon of the ninth gok established in Jaecheon, Chungbuk by Se-hwa Park(朴世和, 1834~1910), which is inferred to be the name of Gugok having the same origin. In addition, the Daeeunbyeong(大隱屛) of the sixth gok. of land route corresponds to the Chu Hsi's Wuyi-Gugok of the seventh gok, which is acknowledged as the basis for Gugok Wollim, and the rock writings and stonework of 'Amseojae(巖棲齋)' and 'Pogyeongjae(抱經齋)' between the seventh gok and eighth gok is a trace comparable with Wuyi Jeongsa(武夷精舍) placed below Wuyi Gugok Eunbyeon-bong, which is understood to be the activity base of Cheongryu-dong of the Giho Sarim(畿湖士林). The rock writings in the Mt. Dongak area, including famous sayings by masters such as Sunsaeuhje(鮮史御帝, Emperor Gojong), Bogahyowoo(保家孝友, Emperor Gojong), Manchunmungywol(萬川明月, King Joengjo), Biryeobudong(非禮不動, Chongzhen Emperor of the Ming Dynasty)', Samusa(思無邪, Euijong of the Ming Dynasty), Baksechungpwoong(百世淸風, Chu Hsi), and Chungryususuk-Dongakpungkyung(淸流水石 動樂風景, Heungseon Daewongun) can be said to be a repository of semantic symbolic cultural scenery, instead of only expressing Confucian aesthetics. In addition, Cheongryu Gugok is noticeable with its feature as a cluster of cultural scenery of the three religions of Confucian-Buddhism-Taoism, where the Confucianism value system, Buddhist concept, and Taoist concept co-exists for mind training and cultivation. Cheongryu Gugok has a semantic feature and spatial character as a basis for history and cultural struggle for the Anti-Japan spirit that has been conceived during the process of establishing and utilizing the spirit of the learning, loyalty for the Emperor and expulsion of barbarians, and inspiration of Anti-Japan force, by inheriting the sense of Dotong(道統) of Neo-Confucianism by the Confucian scholar class at the end of the Joseon era that is represented by Ik-hyun Choi(崔益鉉, 1833~1906), Woo Jeon(田愚, 1841~1922), Woo-man Gi(奇宇萬, 1846~1916), Byung-sun Song(宋秉璿, 1836~1905), and Hyeon Hwang(黃玹, 1855~1910).