• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.171-180
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• 2002

The temporal and spatial distributions of phosphorus have been investigated in the Gomso Bay, Korea. TP, PIP, TOP and DIP in sediment were found 548.8mg P kg$^{-1}$ , 426.1mg P kg$^{-1}$ , 122.6mg P kg$^{-1}$ , and 0.217mg P kg$^{-1}$ , respectively with a decreasing order of PIP>TOP>DIP. Any temporal or spatial trend has not been found on the distribution of TP in the sediment, except the high TP values near the mouth of Julpo-chun. We found seasonal patterns high TOP(28.90% of TP) and low TIP(71.10% of TP) in August, but low TOP(15.63% of TP) and high TIP(84.38% of TP) in November. There were three times higher DIP concentration in August than in November. Such case is probably not only due to the enhanced supply of DIP directly from the decomposition of organic matter from overlying water in summer, but also the released phosphate from the adsorbed particulate matter such as PIP under the low pH and Eh conditions at the subsurface layers of the sediment induced by the active microbial respiration of increased organic materials in summer. Primarily, the source of phosphorous from municipal sewage strongly influenced the early stage of the distribution of all the phosphorous in the Gomso tidal flat. Notwithstanding, through the processes of diagenesis in sediment, water temperature and organic contents probably functioned as the key parameters to control the temporal distributions of TOP, TIP and DIP in the Gomso tidal flat.

• The Journal of the Petrological Society of Korea
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• v.25 no.4
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• pp.335-348
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• 2016

The fluvial Tamna Formation, consisting of conglomerate, sandstone and mudstone layers, is widely distributed in Jeiu Island. Various sizes of quartz crystals were identified from most of the Tamna Formation, including the mudstone layer. XRD analysis also shows that the mudstone layer is composed of various minerals, quartz, plagioclase, K-feldspar, mica, magnetite, hematite, olivine, amphibole, gibbsite, calcite, analcime and clay minerals such as illite, kaolinite, vermiculite, smectite, chlorite, $10{\AA}$-halloysite. There is a tendency showing that the more amount of kaolinite, vermiculite, and chlorite is present where the more amount of quartz crystals is present. It is likely that the main source materials contributing to the Tamna Formation were from the parental rocks containing abundant quartz grains, suggesting that the Tamna Formation could not be related to Jeju volcanic rocks, but possibly to pre-existing basement rocks. Thus, we propose that the Tamna Formation was formed from the materials derived from both pre-existing basement rocks and Jeju volcanic rocks, which were subsequently affected by diagenesis, hydrothermal alteration and weathering process.

• Economic and Environmental Geology
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• v.30 no.1
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• pp.35-49
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• 1997

The coal formation of the Deokpyeong area are interbedded along metapelites of the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with small amounts of biotite, chlorite, pyrite and barite. The ratios of $SiO_2/Al_2O_3$, $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ of the coaly metapelite are variable and wide range from 1.80 to 10.21, from 27.8 to 388.8 and from 7.6 to 61.8, respectively. These coal formation were deposited in basin of marine environments, and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of $Al_2O_3$ versus La, La against Ce, the ratios of La/Ce (0.19 to 0.99) and Th/U (0.02 to 4.75). These rocks also show much variation in $La_N/Yb_N$ (1.19 to 22.89), Th/Yb (0.14 to 21.43) and La/Th (0.44 to 13.67), and their origin is explained by derivation from a mixture of sedimentary and igneous rocks. The wide range in trace and REE element characteristics as Co/Th (0.12 to 2.78), La/Sc (0.33 to 10.18), Sc/Th (0.57 to 5.73), V/Ni (8 to 2347), Cr/V (0.02 to 0.67) and Ni/Co (1.56 to 32.95) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation. Deep to pale green barium-vanadium muscovites (vanadium-oellacherite) have been found in this coal formations. Modes of occurrence and grain size of muscovite are heterogeneous, but most of the barium and vanadium-bearing muscovites occur along the boundaries between graphite and quartz grains, ranging from 200 to $350{\mu}m$ in length and from 40 to $60{\mu}m$ in width. Results of X-ray diffraction data of the minerals characterized to be monoclinic system with $a=5.249{\AA}$, $b=8.939{\AA}$, $c=20.924{\AA}$ and ${\beta}=95.894^{\circ}$. Representative chemical formula of the muscovite was $(Na_{0.09}K_{1.44}Ba_{0.46})(Al_{2.75}Ti_{0.07}V_{0.56}Fe_{0.08}Mg_{0.50})(Si_{6.12}Al_{1.88})O_{22}$. The V possibly substitute octahedral Al, and the Ba is coupled substitution of $K^+Si^{4+}=Ba^{2+}Na^+Ca^{2+}$, which compositional ranges of V and Ba are from 0.42 to 0.69 and from 0.34 to 0.56 based on $O_{22}$, respectively. Formation mechanism of the barium-vanadium muscovites in the coaly metapelite is shown that the formed by high pressure and temperature from regional metamorphism origanated during diagenesis at the interface between a basinal brine and organic matter.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.221-229
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• 2006

Mineralogical and chemical examinations were performed on interstratified illite-smectite (I-S) minerals that occur in the mudstones from a petroleum exploration well in the Tertiary marine basin, Japan. X-ray diffraction analysis shows that component layers of illite in the interstratified I-S increase with increasing burial depth while those of smectie decrease. In addition, the randomly (R=0) interstratified illite-smectite is changed into Rp1 ordered I-S at a depth of about 4,000 m, which corresponds to the result of organic analysis and indicates a burial temperature of about $100^{\circ}C$. However, the present geothermal gradient shows that the conversion of the random I-S to R=0 ordered I-S is likely to occur at 3,000 m. This discrepancy may be interpreted by the reverse fault at 2,500 m which resulted in a deeper burial of sediments up to 1,000 m. Chemical analysis also shows the compositional variation in I-S with increasing depth: a decrease in Si and an increases in Al and K, indicating that the substitution of Al for Si in tetrahedral sheets is compensated by the addition of K to interlayers. K may be derived from K-feldspar and micas, which is present in the mudstones.

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.135-145
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• 2004

A zeolitic bentonite, which exhibits whitish appearance and contains considerable amounts (nearly 〉 5%) of zeolites, frequently occurs as thin beds less than 1 m in Yeongil area. The bentonites are mostly found in closely association with zeolite beds in the Nuldaeri Tuff and Coal-bearing formations of the Janggi Croup. A discordant occurrence of the bentonite against the bedding plane is also locally found. Montmorillonite, the major mineral constituent of the bentonite, is mostly associated with clinoptilolite as a zeolite. However, instead of clinoptilolite, mordenite is sometimes included in the case of more silicic bentonite, and heulandite in the less silicic one. It is characteristic that the mordenite is accompanied by lots of opal-CT in the silicic bentonite. SEM observations characteristically indicate that these authigenic phases, especially the montmorillonite and zeolite, nearly coexist as mixtures not forming a fine-scale zoning. The zeolitic bentonite seems to be formed in the comparatively silicic pore fluid at the alkaline condition accompanying pH fluctuation Compared to the zeolite-free normal bentonite, the zeolitic types exhibit somewhat higher REE abundance. These chemical characteristics, together with modes of occurrences and authigenic mineral associations, may suggest that the zeolitic bentonite is not merely diagenetic products and a possible hydrothermal alteration could not be excluded in the bentonite genesis.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.85-100
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• 2010

Devonian Cairn Formation is one of the important hydrocarbon reservoirs in Alberta, Canada. However, the Cairn Formation, outcropped in the study area, is not prospective reservoir with poor porosity and permeability by some late diagenetic processes. In this study, geochemical characteristics of the Cairn Formation were studied to use these preliminary results for advanced geological and geophysical petroleum explorations in the near future. Rock-Eval pyrolysis showed that total organic carbon content is less than 0.3 wt.%, indicating a minor amount of bitumen and/or other hydrocarbons. The carbonates in the Cairn Formation are mainly composed of subhedral and anhedral dolomites. Pore sizes in the carbonate are various, ranging from nanometer to micrometer. Clastic sediments increase in the upper and lower parts of the Cairn Formation, probably due to changing its depositional conditions. The Cairn Formation can also be divided into several intervals based on Ca/Mg ratio in dolomite and degree of amount of calcite. These could be formed by different sedimentary environment, degree of cementation and recrystallization, different saline/fresh water, etc.

• Analytical Science and Technology
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• v.27 no.6
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• pp.300-307
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• 2014

For the application of chemical assessment standards by the extent of diagenetic alteration, we investigated three archaeological animal bones and a modern animal bone using Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy and x-ray diffraction (XRD) analysis. The calculating results of crystallinity index (CI), carbonate-to-phosphate (C/P) and carbonate-to-carbonate (C/C) using FTIR-ATR spectra showed differences CI and C/P according to the preservative condition of animal bones. By comparison of the crystallinity contents using XRD patterns, the states of animal bones were distinguished to the range of $30^{\circ}-35^{\circ}$. As results of FTIR-ATR and XRD analysis, it is suggested that Mongolian large mammals bone presents the best preservative condition, and cattle bone from Naju site, and Haman site followed. In addition, those were correlated with the results of histological index. The results suggested that the chemical assessment standards may contribute to application of predictions of the states of animal bones discovered from Korea.

• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.195-211
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• 2005

The Kusandong Tuff, known as a representative key bed in the Cretaceous Gyeongsang Basin, is a crystal-rich tuff of pyroclastic flow and surge origin. It is 1-4 m thick and laterally extends for more than 200 km intercalated in the upper part of the Hayang Croup. Observations and analyses of the feldspar crystals in the tuff, using polarizing microscopes, EPMA, and BSE images, reveal that the plagioclase crystals in the tuff were completely albitized (>$97\%$ Ab) whereas those in the southernmost localities where the tuff is rich in fine ash matrix are unaltered or partly albitized. K-feldspars are partly albitized at all localities, irrespective of the matrix content of the tuff, Perthitic textures, chessboard twinning, albitization along micro-fractures and cleavages, and the relationship between matrix content and the degree of albitization suggest that feldspars in the Kusandong Tuff were albitized by Na-rich fluid after burial. Albitization is interpreted to start preferentially along micro-fractures and cleavages and be hampered in matrix-rich tuffs with a low permeability. Original composition of the plagioclases in the Kusandong Tuff is also interpreted to have ranged between oligoclase and andesine ($Ab_{62.5}-Ab_{83.3}$) before the albitization.

• Journal of the Mineralogical Society of Korea
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• v.2 no.2
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• pp.73-80
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• 1989

The sedimentary siderite rock or siderostone has been firstly found from the upper part of the Cambrian Myobong Slate in the Sangdong Tungsten Mine area. It occurs as layers between slate and calc-silicate rock (originally siliceous ankerite rock and ferroan dolostone) or within calc-silicate rock. Some parts of the siderostone bed, however, are considerably skarnized to iron-rich skarns, leaving only small-scaled relics. Siderostone consists mainly of siderite and quartz with minor amount of bertioerine and fluorite or apatite and is commonly microcrystalling granular in texture. Stratification is well developed in some siderstone. The siderostone and its skarnized rocks occasionally contain scheelite grains. Siderite also occurs in sandstone and slate. Mineralogy and textures of the siderostone suggest that it might be formed in the shallow marine basin where enough organic matter was present to maintain a low Eh and iron was supplied, and that siderite might be formed largely by diagenesis from iron-rich berthierine mud.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.71-85
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• 2014

To study biogeochemical characteristics and origin organic matter, sediment samples were taken from Site of 1249C and Stie 1251B of ODP Leg 204. Data of Rock-Eval, isotope, and element analysis generally indicate dominance of marine organic matter in sediments deposited under marine sedimentary environment. Only Rock-Eval data are somewhat different from those of others owing to under-maturation of organic matter. Samples of Site 1249C show high content of gas hydrate, whereas Site 1251B low content of gas hydrate in some intervals of the core. This result may be accounted to different location of two cores and presence of transportation passage (Horizon A, BSR 2) of thermogenic gas in the core, 1249 C. However, Site 1251B Located in the basin of low accumulation of gas hydrate is presumed to be limited in the gas hydrate production. Because not only transportation passage is limited to move thermogenic gas from the core, but also gas supply was not enough. Therefore, the biogenic gas that resulted from diagenesis of there sediment is superior.