• Journal of the Korean earth science society
• /
• v.36 no.6
• /
• pp.543-552
• /
• 2015

This study examines the processes of rock weathering and tafoni formation targeting tafoni at Mt. Cheonsaeng, Gumi-si, Gyeongsangbuk-do. In the study area, a frequency of tafoni is high in conglomerate and conglomeratic sandstone among regional sedimentary rocks, which means that an initial stage of the formation begins a breakaway of gravel from bedrock and also exfoliation from rock surface. Geomorphologically tafoni have intensively been developed at the southfacing slope with exposed rocks, which means that its formation was favorably controlled by environmental conditions including strong influences of mechanical weathering in winter and chemical weathering in summer times. The results of measuring water content at a tafoni-bearing rock surface using GIS interpolation analysis indicate that moisture rate in/around tafoni is higher than the periphery. Thus, it is considered that moisture distribution at a rock surface plays a role in its formation. Analysis of percipitation and secondary minerals induced by chemical weathering is in progress.

• Journal of the Korean Geographical Society
• /
• v.50 no.5
• /
• pp.505-514
• /
• 2015

This study analyzes a correlation between water content values and chemical index of alteration (CIA) for coarse sedimentary rocks of Mt. Cheonsaeng in Gumi-si, Kyeongsangbuk-do. Through measurement of various water values of 20 samples including water content rate, water absorption rate and equipment measuring we comparatively analyzed the values with CIA of the samples obtained by X-ray fluorescence. As a result of analysis water content rate and water absorption rate in a sedimentary rock are likely to be higher when matrix is psephitic and less compact. Furthermore the higher water content rate is, the higher CIA is due to increase of $SiO_2$ and $Al_2O_3$ and decrease of CaO and $Na_2O$ derived by chemical weathering of felspar. This correlation between water content rate and CIA represents a similar result with previous studies targeting granite.

• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.3
• /
• pp.211-214
• /
• 1999

To acknowledge the differences in soil physical properties of cultivated land derived from major parent rocks in Yeong-nam areas, we investigated Riley's projection sphericity(one of the morphological properties) of sand and made up Soil Moisture Characteristics Curve(SMCC). The averages in Riley s projection sphericity range from 0.63 to 0.67 in soils derived from Sedimentary rocks than 0.56 to 0.61 in soils derived from igneous rocks. In case of soils derived from igneous rocks, the Riley's projection sphericity is lower as the particle size get to be smaller. The differences of SMCC were larger in the fine loamy soils than in coarse loamy soils. The moisture retention was higher in the soils derived from Sedimentary rocks than in the soils derived from Igneous rocks. After we transformed the water retention into dimensionless scale value by available water ratio, the SMCC was nearly unchangeable in the tested soils except for fine loamy soils derived from Sedimentary rock, but was not correlated with soil texture or parent rocks.

• The Journal of Engineering Geology
• /
• v.8 no.2
• /
• pp.163-173
• /
• 1998

Suite of log analysis techniques consisting of geophysical well log, geological core log, and physical core log have been made to understand the well log responses and to determine the lithology of a test borehole-PABH1 located in Pungam sedimentary basin, Sosok, Hongchon-gun, Kangwon Province. Geological core logging has been precisely made over the cores taken between 64 and 124 meters, and 11 groups of rock types were deduced. Using the core samples divided by 11 groups, geophysical property measurements consisting of resistivity, natural gamma and density were made. Each rock group in the area is shown to have its characteristic physical response from geophysical well log and geophysical core logs. The outstanding physical responses particularly shown from siltstone, coarse sandstone to conglomerate, and granitic gneiss in the area were effectively used as keybeds in correlating the geophysical well logs to the result of geological core logs.

• Economic and Environmental Geology
• /
• v.4 no.3
• /
• pp.113-119
• /
• 1971

The Daeheung Dolomite Mine, which is about 6km south of Danyang, Chungcheongbugdo, is coincided with almost central portion of the Danyang quardrangle scaled in 1 : 50,000. The purpose of this report is to prepare a information for the economic evaluation on the mine. Geology of the region is composed of worm-eaten limestone, crystalline limestone, crystalline dolomite rock, sandstone and shale from bottom, those are applicable to socalled Dumugol and Maggol formation of Ordovician, and batholithic biotite granite is intruded the west-side of the ditto sedimentary rocks. The dolomite bed, emplaced in bottom of the upper limestone formation, so-called Maggol formation, is about 270m in thickness, and dips $30^{\circ}{\sim}50^{\circ}$ northwest. The facies of the dolomite rock contained many brucite crystals is not only coarse-grained crystalline, but also micro crystalline in contact metasomatic parts. 25 samples were taken from the two series, A and B, in the nearly crossed direction to the strike of the dolomite bed as shown in the geological map. They were chemically analysed on the components of MgO, CaO, and $SiO_2$ as shown in Table 2. The estimate ore reserves total some 107,200,000 metric tons above the 320m level with the following average contents: MgO 21.80%, CaO 29.27% and $SiO_2$ 0.64%. It is caused by brucite minerals that MaO content in the dolomite rock is higher than pure dolomite (21.7%). The dolomite ore is possible in use for magnesian fertilizer, magnesian cement and refractory material, especially the microcrystalline dolomite ore is useful for a refractory material in furnaces of iron industries.

• Economic and Environmental Geology
• /
• v.37 no.5
• /
• pp.555-568
• /
• 2004

The demand of aggregate resources in Korea has been increased with a rapid economic growth since the 1980s. About 25% of the total aggregate production is derived from riverine aggregates, 20% to 25% from marine sands, 40% to 45% from crushed aggregate and the rest 5% to 15% from old fluvial deposits. The abundance of crushed coarse aggregates varies in the uniform distribution of country, but in general it can be concentrated in the most densely populated areas, five main cities. Typical rock types of the Korean crushed stones are classified as plutonic rocks of 27%, metamorphic rocks of 32%, sedimentary rocks and volcanic rocks of 18%, respectively. The most abundant coarse aggregate used in the country is obtained from granite (25% of total) and subordinately gneiss (20%), sandstone (10%) and andesite (10%). Although rock types using as dimension stone are only fifteen, those as aggregate amount up to twenty nine rocks. These rocks consist of plutonic rocks such as granite, syenite, diorite, aplite, porphyry, felsite. dike and volcanic rocks such as rhyolite, andesite, trachyte, basalt, tuff, volcanic breccia and metamorphic rocks such as gneiss, schist, phyllite, slate, meld-sandstone, quartzite, hornfels, calc-silicate rock, amphibolite. And sandstone, shale, mudstone, conglomerate, limestone, breccia, chert are main aggregate sources in tile sedimentary rocks. The abundance of plutonic rocks is the highest in Chungcheongbuk-do, and decreases as the order of Jeollabuk-do, Gangwon-do and Gyeonggi-do. In Jeollanam-do, volcanic aggregates occupy above 50%, on the contrary sedimentary aggregates are above 50% in Gyeongsangnam-do.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.5551-5557
• /
• 2012

Sedimentary rocks dug up in construction fields are mostly stockpiled for landfill disposal, leading to an increase in construction costs and construction inefficiency. After screening, some of the sandstone can be used as aggregate; however, most of the shale ends up as industrial waste in practice. In this study, to stabilize the demand and develop resources for alternative aggregates of concrete, the potential use of shale, which is widely distributed in the Daegu-Kyeongbuk region, as a concrete aggregate was evaluated. Red and black shale exported from a Daegu excavation site was selected for use in the experiments and evaluated by comparing with hornfels, which is widely used as a coarse aggregate and is a type of andesite and metamorphosed sedimentary rock. The physical properties of the aggregate were evaluated in accordance with the test methods of KS F 2527 "crushed concrete aggregate," and the compressive strength against the shale aggregate replacement ratio was measured. The compressive strength of the concrete after 28 days was 30.8 MPa when the black shale replaced 100% of the aggregate in the concrete and 31.1 MPa when the red shale replaced 100% of the aggregate in the concrete. Compared with the compressive strength of 37.5 MPa for concrete prepared by using plain aggregate, using shale as a substitute for the aggregate produced an average compressive strength that was 82% of normal concrete.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.20 no.4
• /
• pp.1-14
• /
• 2017

In Korea, the soil series derived from sedimentary rocks are classified into seven soil series of coarse loamy soil such as Dain, Danbug, Dongam, Imdong, Jeomgog, Maryeong, and Yonggog; seventeen soil series of fine loamy soil such as Angye, Anmi, Banho, Bigog, Deoggog, Dogye, Dojeon, Gamgog, Gugog, Jincheon, Maji, Mungyeong, Oggye, Samam, Yanggog, Yeongwol, and Yulgog; six soil series of fine silty soil such as Goryeong, Bonggog, Juggog, Gyeongsan, Yuga, and Yugog; and four soil series of clayey soil such as Mitan, Pyeongan, Pyeongjeon, and Uji. All thirty-four soil series have different drainage rates and topography. However, the soil texture depends on the parent rock. The buffer functions in GIS (Geographic Information System) techniques were used to calculate adjacent soil series from a soil series. The length of the adjacent soil series was adjusted because a side of the buffer area was one meter long. The cluster analysis was conducted using the CCC (Cubic Clustering Criterion) method, in which the number of clusters is calculated based on the individual soil series ratio. Soil survey has been carried out since 1964 as "The reconnaissance soil survey", and 1:5,000 detailed soil survey was completed in 1999 with a five-years plan in Korea. Today, all the soil survey information has been computerized. GIS techniques were used to establish a digital soil map; however, there have not been any studies to interpret pedogenesis using the GIS technique. In this study, the area of the adjacent soil series were obtained using the GIS technique. The area of the adjacent soil series can be calculated based on the information area. The similarities of soil originated from sedimentary rocks were estimated using the length. As a result, the distribution of grain size was different based on the types of sedimentary rocks and the location. The clusters were distinguished into limestone, sandstone, and shale. In addition, the soil derived from shale was divided into red shale and gray shale. This means that quantitative interpretation of the catena and this established method can be used to interpret the relationship between soil series.

• The Korean Journal of Petroleum Geology
• /
• v.6 no.1_2 s.7
• /
• pp.8-19
• /
• 1998

In the Sinri area located at the mid western boundary of the Jinan basin, the Manduksan Formation which mainly consists of coarse sandstone narrowly intercalated with shale and the alternation of sand and shale and the Dalgil Formation mainly of shale are distributed. It consists of four lithofacies, such as coarse sandstone, interbedded sandstone/shale, shale and volcanic rock lithofacies. All sediments are interpreted to be deposited by turbidity currents and free fallouts in a lacustrine basin. In these rocks many penecontemporaneous defomation structures are observed such as fold and thrust fault at large scale, and swelling, boudin structure, flame structure, load structure, ptygmatic fold and convolute bedding at small scale. All these structures are developed between upper and lower undisturbed sedimentary strata. Two large folds are similar folds, but lower one gradually developed into concentric shape. The swelling structures by convergence of the sediments are observed in the hinge area and the boudin structures are developed in the limb. The thrust faults including minor folds and sandstone lobes show duplex structure with asymmetric and kink fold on and below in front of the detached sandstone layer. Development of the swellings, boudins and lobes indicates the flexbility of the sediments during deformational episodes. The folds and thrust faults rarely contain fractures relative their scales and lithologies. This feature also indicates the retrievability of sediments during deformation. At the flanks of the thrust faults the normal faults are formed contemporaneously. The deformation structures at small scale such as flame structures, load structures, ptygmatic folds and convolute beddings are syndepositional and penecontemporaneous, which show the effects of tectonic movements. All these deformed sedimentary structures of the Sinri area suggest the continuing tectonic movements during and/or after deposition.

• The Journal of the Petrological Society of Korea
• /
• v.15 no.3 s.45
• /
• pp.154-166
• /
• 2006

Though there are more than 600 active and non-active dimension stone quarries in Korea, most quarries are small-scaled and non-active. Main dimension stone belt in Korea is distributed in the Wonju-jecheon-Mungyeong-Geochang-Jinan-Nanwon-Geogumdo area with NNE direction, which occupies about 50% of domestic dimension stone quarries. The other dimension stone belts occur in the Gangyeong-Iksan-Gimje area, the Pocheon-Ujeongbu area and the Boryeong area. The dimension stones in Korea have been produced from at least fifteen rock types: granite, diorite, syenite, gabbro, homblendite, basalt andesite, rhyolite, tuff felsite, sandstone, marble, gneiss, schist and slate. However, seven or eight rock types such as granite, diorite and marble are currently produced. The dimension stones are quarried out 87% from plutonic rocks (mainly granite and diorite), 6% from sedimentary rocks (mainly sandstone), and 3% from metamorphic rocks (mainly marble). Main rock types of the dimension stones are variable with respect to their production locality. In the Jeollanam-do area, most dimension stones are produced from diorite. Marble is mainly produced from the Gangwon-do and Chungcheongbuk-do areas. Black sandstone is exclusively quarried out from the Chungcheongnam-do area. Granite is most abundant dimension stone in Korea. Above 50% of the domestic dimension stones are medium-grained to coarse-grained granitic rocks, but fine-grained granite dimension stones have 10% of distribution. The color of the dimension stone varies with rock types. Most granite dimension stones have dominant colors of whitish gray and gray, which are produced from the Wonju, Gapyeong, Iksan, Namwon and Geochang areas. Pink-colored granites are rarely produced from the Mungyeong area.