Study on the Material and Deterioration Characteristics of the Stone Seated Buddha Triad and Stone Standing Buddha in Bijung-ri, Cheongju, Korea

The Stone Seated Buddha Triad and Stone Standing Buddha in Bijung-ri are state-designated heritage (treasure) statues having the Buddha style of the Goryeo dynasty from the 6th century. Conservation scientific investigations were conducted to understand the preservation status of these stone Buddha statues and to establish a conservation plan. The Stone Seated Buddha Triad and Stone Standing Buddha are composed of fine-medium grained biotite granite, which is considered to be of the same origin owing to their low magnetic susceptibility distribution of less than 0.2 (×10-3 SI unit) and similar mineral characteristics. The Stone Seated Buddha Triad has highly homogenous mineral composition and particle size, whole-rock magnetic susceptibility, and geochemical characteristics very similar to those of the nearby outcrop. It was confirmed that a combination of physical, chemical, and biological factors affects the Stone Buddha statues. In particular, both the Stone Seated Buddha Triad and Stone Standing Buddha tend to be chipped off from the front and cracked and scaled from the back. The Stone Standing Buddha located outdoors experiences granularity decomposition and black algae formation, which accelerate the weathering under unfavorable conservation environments. The result of non-destructive physical property diagnosis using ultrasonic velocity showed that both the Stone Seated Buddha Triad and Stone Standing Buddha have been completely weathered (CW), indicating very poor physical properties.

Geological Controls on Mineralogical Characteristic Differences of Coals from the Main Coal Fields in Shaanxi, North China

Shaanxi is among the provinces with abundant coal resources in North China. These enormous coal resources (approx. 4143 Gt) are widely distributed in the Ordos Basin and its marginal fold belts. The main coal-bearing strata consist of the late Carboniferous Taiyuan Formation, the early Permain Shanxi Formation, the late Triassic Wayaobao Formation, and the middle Jurassic Yan’an Formation, which were respectively deposited in coastal plains and a lagoon environment, a continental environment, an inland open lake and a confined lake environment. The Permo-Carboniferous coals are low volatile bituminous and characterized by relatively high vitrinite content, which decreases from south to north, and from the lower coal seams upwards. By contrast, the late Triassic and middle Jurassic coals are highly volatile bituminous, but are respectively characterized by relatively high vitrinite and high inertinite content. Minerals in the Permo-Carboniferous coals, the late Triassic coals, and the middle Jurassic coals, are respectively dominated by kaolinite and calcite, quartz and kaolinite, and quartz and calcite. Furthermore, contemporary coals deposited in different coal fields or even different mines of the same coal field present different mineral characteristics. The Permain Shanxi Formation coals from the Shanbei C-P coalfield in the north of Shaanxi Province are characterized by higher kaolinite and lower carbonate contents compared to those from the Weibei C-P coalfield in the south of Shaanxi Province. The distinctive mineralogical characteristics of coals formed in different coalfields and different geological ages were ascribed to integrated influences of different terrigenous detrital input from sediment provenance, sedimentary settings (e.g., subsidence rate, sea transgression, and regression process), and hydrothermal activities.

Geochemical - geology characteristics implicating original sources and copper - deposit type in Kon Ra ore - field

Based on the research results on petrographic - mineralogical characteristics, tectonic structural features, geochemistry of major and trace elements of the bedrock, alternative rock, ore, soil, mineralogical geochemistry, mineral facies, inclusions, the origin of ore formation related to oxidized granite and skarnoid - typed metasomatic process in Kon Ra copper ore field have been identified. Petrological and mineral characteristics indicate the process of transitional metasomatism between the skarn and hornfels, also known as bimetasomatic stage (skarnoid deposit type). Diopxite represents the Progade skarnoid stage. Tremolite, actinolite, quartz, chlorite, magnetite, molybdenite, less of chalcopyrite, pyrrhotite, and pyrite indicate the retrogade skarnoid stage. The following is sulfide - quartz stage (major minerals include: quartz, chalcopyrite, pyrite, pyrrhotite, molybdenite). This result is also consistent with the formation temperature 210÷270 0C and the geochemical zoning of elements from intrusive blocks through the outer contact zone that contains the ore and surrounding rocks are as follows: Cu, Zn, Ca (the zone has lime-rich formations), Fe3+, Mo increases in the outer contact zone containing ore closed to acid intrusive rocks. Inversely, the ratios of Pb/Cu, Zn/Cu, and As content increased in the alteration from this zone to the outer one. In addition, uranium mineralization is associated with a later magma stage (pegmatite granite in endo-contact is high uranium radiation: U = 0.17÷0.2%, 3,420,000÷8,020,000 µR/h and contains uraninite).

Root carbon interaction with soil minerals is dynamic, leaving a legacy of microbially-derived residues

Minerals preserve the oldest most persistent soil carbon, and mineral characteristics appear to play a critical role in the formation of soil organic matter (SOM) associations. To test the hypothesis that carbon source and soil microorganisms also influence mineral-SOM associations, we incubated permeable minerals bags in soil microcosms with and without plants, in a 13CO2 labeling chamber. Mineral bags contained quartz, ferrihydrite, kaolinite, or native soil minerals isolated via density separation. Using 13C-NMR, FTICR-MS, and lipidomics, we traced plant-derived carbon onto minerals harvested from microcosms at three plant growth stages, characterizing total carbon, 13C enrichment, and SOM chemistry. While C accumulation was rapid and mineral-dependent, the accumulated amount was not significantly affected by the presence of plant roots. However, the rhizosphere did shape the chemistry of mineral-associated SOM. Minerals incubated in the rhizosphere were associated with a more diverse array of compounds with different C functional groups (carbonyl, aromatics, carbohydrates, lipids) than minerals incubated in a bulk soil control. These diverse rhizosphere-derived compounds may represent a transient fraction of mineral SOM, rapidly exchanging with mineral surfaces. Our results also suggest that many of the lipids which persist on minerals are microbially-derived with a large fraction of fungal lipids.

Mineral characteristics of metacarbonat in Sa Thay, Kon Tum and potential use for gemstone

Metacarbonates located in Sa Thay, Kon Tum massif are distributed in ultramafic marble assemblage from Kham Duc (NP-e1kđ) complex.The main rock-formingminerals arecalcite and dolomite (40÷85%), olivine (5÷20%), pyroxene (5÷15%), and serpentine (5÷25%). Accessory minerals aretalc and epidote. Chemical composition of pyroxene in metacarbonate was determined by EPMA method: the composition of pyroxene is diopsite (Wo49.5 En50.1Fs0.4 to Wo50.8En48.9Fs0.2). The rim of pyroxene grains generally have higher wollastonite than core(49.9÷50.8%).Metacarbonates originated from metamorphic sources with three main stages: regional metamorphism, superimposed metamorphismand hydrothermal metamorphism stages. With each stage, they have different color characteristicsto create a variety of color. Metacarbonateshave quality characteristicsofcolor, durability, pattern, diversity, and low radioactivity. These make the metacarbonates suitable for gemstone applications.

Seepage field characteristic and stability analysis of tailings dam under action of chemical solution

As one of the important influencing factors of tailings dam stability, seepage field distribution within the dam is often affected by the tailings mineral characteristics. While the alkalinity or acidity of reservoir water and long term immersion will partially change the physical and mechanical properties of tailings. This study carried out permeability tests of tailings under the action of chemical solution. On this basis, a three dimensional (3D) model was constructed to analyze the velocity field and effective saturation within the tailings dam. Moreover, the dam section along the valley bottom was selected as the basic section in calculation, so as to analyze the changes in infiltration point and buried depth of the phreatic line under different permeability coefficient ratios. The results suggest that, under the action of acid-alkaline solution, the permeability coefficients of tailings reduced, and the stronger solution acidity-alkalinity resulted in the longer action time and more obvious change; under the action of chemical solution, the fluid flow velocity in the dam gradually decreased, and the drat beach length in the reservoir gradually shortened. Besides, when the upper layer permeability coefficients of tailings was lower than that of the lower layer, the dam phreatic line had a shallow buried depth and a high infiltration point.

Mineral Characteristics of Low-Rank Coal and the Effects on the Micro- and Nanoscale Pore-Fractures: A Case Study from the Zhundong Coalfield, Northwest China

The mineral characteristics (occurrence, type, and content) of low-rank coal and their influence on coalbed methane (CBM) reservoirs are investigated at the micro- and nanoscales. Six coal samples of three representative coalmines were used to demonstrate the uniform tectonization from the Zhundong coalfield, NW China. Based on optical microscopy and scanning electron microscopyenergy dispersive spectrum (SEM-EDS) analysis, the mineral composition and occurrence characteristics were discussed. The micro- and nanoscale reservoir characteristics in low-rank coal (pore size distribution and adsorption capability) were studied by diverse methods, including lowtemperature N2 adsorption/desorption, mercury intrusion porosimetry and CH4 isotherm adsorption analysis. The coal reservoir nuclear magnetic T2 spectra of porosity and movable fluid were obtained by combining low-field nuclear magnetic resonance (NMR) analysis, which has an advantage of determining pore fluid technology. The mineral content is highly variable (4˜16 vol.%) in the Xi Heishan prospecting area of the Qitai region. Kaolinite, goyazite, ankerite and anorthosite were microscopically observed to be filling in coal pores and microfractures, and the minerals are given priority to silicate minerals. There is a greater content of mesopores (100–1000 nm) and transition pores (10–100 nm), and they are well connected. The micropores (0–10 nm) are dominated by parallel plate, closed or wedge-shaped pores. Furthermore, the microfractures are mainly observed for types B (width ≥ 5 μm and length≤ 10 mm) and D (width<5 μm and length<300 μm). The results show that microfractures B and C (width< 5 μm and length ≥ 300 μm) are better connected, but the orientation and connectivity of type D are worse. The Langmuir volume and mesopore content decreased with increasing mineral content, which shows that the low-rank coal minerals filled some adsorption space; the reduced CBM adsorption capacity and cellular pore and intergranular pore filled with minerals affect the mesopore content. Therefore, mineral characterization significantly influences methane adsorption capacity and pore structure.