• The Journal of the Petrological Society of Korea
• /
• v.23 no.4
• /
• pp.337-349
• /
• 2014

We measured rare earth element and Zr concentrations of USGS granite standard material GSP-2 and GSJ granite standard material JG-1a to clarify the effect of zircon during rare earth element analysis using ICP-MS. We also measured rare-earth element and zirconium (Zr) contents of zircon from granite by acid-digestion methods using conventional teflon vial and pressure-bomb. The results show that acid-digestion using teflon vial dissolved ca. 50% of zircon compared to pressure-bomb method. The Zr contents of JG-1a and GSP-2 gave ca 50% of reference value. However, rare-earth element abundance of JG-1a and GSP-2 were similar to those of reference values. This suggests that the decomposition degree of zircon might give a negligible effect on a petrological and geochemical interpretation using chondritenormalized REE pattern.

• Economic and Environmental Geology
• /
• v.51 no.6
• /
• pp.509-520
• /
• 2018

Alkalinity is one of the basic variables, which determine geochemical characteristics of natural waters and participate in processes changing concentrations of various contaminants either directly or indirectly. However, not a few laboratories and researchers of Korea still use alkalinity-measurement methods not appropriate for groundwaters, and which becomes one of the major reasons for the poor ion balance errors of the geochemical analysis. This study was performed to review alkalinity-measurement methods, to discuss their advantages and disadvantages, and, thus, to help researchers and analytical specialists in analyzing alkalinity of groundwaters. The pH-titration-curve-inflection-point (PTC-IP) methods, which finds the alkalinity end point from the inflection point of the pH titration curve are revealed to be most accurate. Gran titration technique among them are likely to be most appropriate for accurate estimation of titrant volume to the end point. In contrast, other titration methods such as pH indicator method and pre-selected pH method, which are still commonly being used, are likely to cause erroneous results especially for groundwaters of low ionic strength and alkalinity.

• Korean Journal of Heritage: History & Science
• /
• v.36
• /
• pp.267-297
• /
• 2003

The plain coarse pottery from the Unjeonri Bronze Age relic sites in the Cheonan, Korea were studied on the basis of clay mineralogy, geochemistry and archaegeological interpretations. For the research, the potteries are utilized at the analysis for 6 pieces of plain coarse potteries. Color of the these potteries are mainly light brown, partly shows the yellowish brown to reddish brown. The interior, surface and inside of the pottery appear as different colors in any cases. Original source materials making the Unjeonri potteries are used of mainly sandy clay soil with extreme coarse grained irregularly quartz and feldspar. The magnetic susceptibility of the Unjeonri pottery range from 0.20 to 1.20. And the Unjeonri soil's magnetic susceptibility agree almost with 0.20 to 1.30. In the same magnetization of soil and pottery, the results revealed that the Unjeonri soil and low material of pottery are same produced by identical source materials. The Unjeonri potteries and soil are very similar patterns with all characteristics of soil mineralogy, geochemical evolution trend. The result seems to be same relationships between the behavior and enrichment patterns on the basis of a compatible and a incompatible elements. Consequently, the Unjeonri potteries suggest that made the soil to be distributed in the circumstance of the relic sites as the raw material are high in a greater part. In the Unjeonri soil, the kaolinite is common occurred minerals. However, in the Unjeonri pottery, the kaolinite was not detected in all broken pieces. The kaolinite was presumed to destroy crystal structure during the firing processes of over $550^{\circ}C$. The quartz is phase transition from ${\alpha}$-quartz to ${\beta}$-quartz at $573^{\circ}C$, but the Unjeonri pottery did not investigated any phase transition evidences of quartz. The chorite was detected within the mostly potteries and soils. As the results, the Unjeonri potteries can be interpreted by not experiencing a firing temperature over $800^{\circ}C$. The colloidal and cementing materials between the quartz and low materials during the heating did not exist in the internal part of the potteries. An any secondary compounds by heating does not appear within the crack to happen during the dry of the pottery. The hyphae group are kept as it is with the root tissue of an organic matters to live in the swampy land. In the syntheses of all results, the general firing condition to bake and make the Unjeonri pottery is presumed from $550^{\circ}C$ to $800^{\circ}C$. However, the firing condition making the Unjeonri pottery can be different firing temperature partially in one pottery. Even, the some part of the pottery does not take a direct influence on the fire.

• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.655-666
• /
• 2020

This study evaluated the characteristics of arsenic production in groundwater through microbial community analysis of groundwater contaminated with high arsenic in Haman area. Groundwater in Haman area is contaminated with arsenic in the range of 0-757.2 ㎍/L, which represents the highest arsenic contamination concentration reported in Korea as natural groundwater pollution source. Of the total 200 samples, 29 samples (14.5%) showed higher arsenic concentration than that of 10 ㎍/L, which is the standard for drinking water quality, and 8 samples (4%) found in wells with 80-100 m depth were above 50 ㎍/L. In addition, seven wells with arsenic concentration more than 100 ㎍/L located in the northern part of Haman. As a result of microbial community analysis for high arsenic-contaminated groundwater, the microbial community compositions were significantly different between each sample, and Proteobacteria was the most dominant phyla with an average of 61.5%. At the genus level, the Gallinonella genus was predominant with about 12.8% proportion, followed by the Acinetobacter and Methermicoccus genus with about 7.8 and 7.3%, respectively. It is expected that high arsenic groundwater in the study area was caused by a complex reaction of geochemical characteristics and biogeochemical processes. Therefore, it is expected that the constructed information on geochemical characteristics and microbial communities through this study could be used to identify the origin of high arsenic groundwater and the development of its controlling technology.

• Journal of Conservation Science
• /
• v.37 no.6
• /
• pp.748-766
• /
• 2021

The Iksan Ssangneung (twin tombs), a pair of tombs comprising the Daewangneung (large royal tomb) and the Sowangneung (small royal tomb), were constructed in the typical style of stone tunnel and chamber tombs in the Baekje Kingdom during the Sabi period (538 to 660 AD) of ancient Korea. Soil layers exposed during excavation of Sowangneung in a trench east of the tomb are: the bottommost layer, the ground level layer, the Panchuk (rammed earth) layer of the Baekje, the layer created by a grave robbery, and soil recovered during the Japanese colonial period. Soil samples were obtained by segmenting an easy stratigraphic horizon into sub categorized soil layers, and their material properties were analyzed; they are composed mainly of sandy loam based on the particle size distributions. In the site foundation, loamy sand is packed in the bottommost layer, and sandy loam with high sand and silty sand fills most of the overlying layer. The central and topmost portion of the Baekje layer is composed of loam with high clay content. All soil layers show geochemical behaviors similar to those of the bottommost layer. X-ray diffraction analysis verified kaolinite in all layers, also observed in soil layers displaying high crystallinity. Kaolinite and halloysite were identified by scanning electron microscopy. Thus, we conclude that the Baekje layer of the Sowangneung is composed of sandy loam containing kaolin procured from near the site. An impermeable middle to upper layer was created using viscous loam. The top of the tomb was closed tightly.

• Economic and Environmental Geology
• /
• v.56 no.6
• /
• pp.799-816
• /
• 2023

Mineralogical and geochemical studies of shales within the Lower Anambra Basin was conducted to unravel the depositional environment, provenance, maturity, paleo-weathering conditions, and tectonic settings. Mineralogical studies conducted using X-ray diffraction analysis revealed that the samples were composed of kaolinite, montmorillonite, chlorite, and illite. KaolinIite is the dominant mineral, constituting approximately 41.5% of the bulk composition, whereas the non-clay minerals are quartz, ilmenite, and sillimanite. Geochemical analysis showed a predominance of SiO₂, Al₂O₃, and Fe₂O₃ contents of the shale samples with mean values of 52.29%, 14.09%, and 6.15% for Imo Shale (IS); 52.31%, 16.70%, and 7.39% for Mamu Shale (MS); 43.21%, 21.33%, and 10.36% for Enugu Shale (ES); 53.35%, 15.64%, and 7.17% for Nkporo Shale (NS); and 51.24%, 17.25%, and 7.78% for Agwu Shale (AS). However, the shales were depleted in Na₂O, MgO, K₂O, MnO, TiO₂, CaO, and P₂O₅. The trace element ratios of Ni/Co and Cu/Zn of the shale suggest an oxic depositional environment. The average SiO₂ vs. Al₂O₃ ratio of the shales indicated textural maturity. Compared to the PAAS standard, the shales plot below the PAAS value of 0.85, suggesting a high degree of maturity and intensive chemical weathering, further confirmed on a CIA vs. PIA plot. On log (K₂O/Na₂O) against SiO₂ and tectonic setting discriminant function diagrams, the shales plot mostly in the field of passive continental margin tectonic setting. The discriminant function diagrams as well as Al₂O₃/TiO₂ ratio of the shales showed that they were derived from a mixed source (mafic and intermediate igneous rocks).

• Explosives and Blasting
• /
• v.19 no.3
• /
• pp.91-104
• /
• 2001

As in Korean environments with mountainous and hilly areas, the rock generally has to be removed in construction or civil engineering work in tunnelling or excavation for development in urban area. Explosives should be used for blasting, which may cause serious problems on local people for their claim for compensation due to ground vibration, noise. For safe and economic blasting, geology and engineering characteristics of rocks such as discontinuities of rock or weathering are very important factors, together with site characteristics for prediction of ground vibration. In this study, conducted were the detailed study for major rocks most widely distributed in the South-east area, in-situ geological survey, geological and geochemical analysis, and further laboratory uniaxial rock stress, seismic velocity of core samples together with in-situ seismic velocity measurements. Regulations on ground vibration and noise were reviewed for assessing their adaptabilities, and a total of 4,856 measured blasting vibration data were examined for enhancing the confidence level in estimating the predictive formulation using scaled distance statistically.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.107-111
• /
• 2003

Estuary of Nakdong river area is composed of unconsolidated sediments including clays that are deposited varying from 40 to 70m thick. The purpose of research is the knowledge of the correlation between engineering properties and mineralogy of clay sediments. The correlation analysis carry out multiple regression that have independent variables (Engineering properties) and dependent variables (mineralogy, geochemistry). Engineering properties of clay are correlated with the mineral compositions and geochemical characteristics. The result of the analysis is Wn=-0.6 Feldspar ＋ 1.1 pH ＋ 0.01 TDS ＋ 27.5, Ip=0.36 Clay ＋ 1.44 Vermiculite ＋ 0.94 clay mineral-22.88, P$_{L}$=0.005 TDS - 0.31 Feldspar ＋ 22.43, e$_{o}$=0.02 Vermiculite - 0.01 Quartz ＋ TDS ＋ 0.93, E$_{50}$=1.94 Vermiculite-0.96 Kaolinite -0.53 silt ＋ 49.64, SR=-0.25 Kaolinite ＋ 1.5 pH - 2.3 Conductivity, CC = 0.03 pH ＋ TDS - 0.2, LL = 0.5 Clay ＋ 1.3 Vermiculite ＋ 5.5 Conductivity ＋ 0.8 Caly mineral-20.4.4.4.4

• Journal of the Speleological Society of Korea
• /
• v.34 no.35
• /
• pp.78-104
• /
• 1993

Analysis of one sinkhole, the Dodgeville sinkhole, developed in Ordovician dolostones in the Driftless Area of Wisconsin in the Upper Midwest'd Driftless Area reveals homogenous clayey sediment fills reflecting a range of dissolutional processes during the Quaternary or Pre-Quaternary. Granulometric analysis, graphical moments statistics, carbonate minerals, ana sand grain lithology were used to differentiate sinkhole sediment sources and modes of accumulation. Sediments in the dolostone sinkholes developed by dissolution. Sediments contain two major types of sediments : residual redish clay( autogenic sediments) and aeolian silt (allogenic sediments). The massive clay is generated from the weathered dolostone bedrocks as a in situ materials. The loessial silt is mostly derived from transportation of the surrounding surface materials, with some evidences of penetrated deposition. Unlike the collapsed sandstone sinkholes (Oh et al., 1993), dolostone sinkholes reveal homogenous, autogenic clay materials, and a geochemical composition indicative of in situ autogenic karstification. Dolostone sinkhole si1ts (26.9%) and sands (34.9%) are derived from weathered Plattevi1le-Galena dolostones, and contain high carbonate(37.5%), chert (57.2%) and lead ore (3%). Graphical moments statistics for sorting, skewness, and kurtosis indicate that sand grains from dolostones were derived entirely from local bedrock by in situ dissolution. Upper sinkhole sediments are pedagogically very young as carbonate is unleashed. Materials of the sinkhole sediment are definitely inherited from internal dolostones by dissolution and weathering, because not only a granulomatric comparison of dolostone and sandstone sediments demonstrates that they have heterogeneous paticle size distributions, but also 1ithologic analyses displays they differ completely.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.85-85
• /
• 2022

The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.