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991.
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Pravin Kumar Sharma Nalin Kumar Johri Gagan Behari Raut G. Rangaswamy Brahma Kishore Pandey Anand Kumar Chaturvedi 《Journal of the Geological Society of India》2018,91(3):281-289
Characterization of the Panandhro lignite deposits from western Indian state of Gujarat, based on the geochemical and palynological evidences, has been performed to assess the floral composition, maturity and hydrocarbon potential of the sequence. Elementally, the lignites consist of moderate carbon, low hydrogen and moderate sulfur contents. The samples are characterized by high TOC contents (lignite: av. 46.43 wt.%, resin: 62.47 wt.%). The average HI values for the lignite is 136 mg HC/g TOC, and that of the associated resin is 671 mg HC/g TOC. The highest Tmax is recoded in lignite (422°C) and lowest in the resin (39°C) samples. The FTIR spectrum of lignite is characterized by highly intense OH stretching peak ~3350 cm-1, aliphatic CHx stretching peaks between 3000-2800 cm-1, aromatic C=O stretching and an aromatic C=C stretching. The spectrum of resin shows strongest absorption due to aliphatic CHx stretching between 2940-2915 cm-1 and 2870-2850 cm-1, and deformation by the medium peak between 1450 and 1650 cm-1. The recovered palynofloral assemblage indicates the dominance of angiosperm pollen grains with maximum abundance of Arecaceae family, and subdominant pteridophytic spores. Marine influence is indicated by the presence of abundant dinoflagellate cysts. The occurrence of flora from a variety of ecological niches suggests a luxuriant diverse vegetation pattern existed in the vicinity of depositional site under humid tropical conditions. The overall characteristics of the lignite deposits point towards their ability to generate (upon maturation) hydrocarbons as they have types III–II admixed kerogen (organic matters). 相似文献
995.
V. V. Ermakov S. F. Tyutikov A. P. Degtyarev V. A. Safonov V. N. Danilova S. D. Khushvakhtova U. A. Gulyaeva E. V. Krechetova 《Geochemistry International》2018,56(4):318-331
Specific responses of plants and animals to changes in the contents of microelements (Pb, Cd, Cu, Zn, As, Se, etc.) in abiotic environmental components of the Ardon River Basin (North Ossetia) were studied by new biogeochemical indication methods. In comparison to background areas, a local increase in the Pb, Cd, Cu, Zn, and As contents in soils and organisms occurs under the impact of natural and technogenic factors. The heavy metal contents in Ardon River water are generally within hygienic norms. Activation of sulfurcontaining synthesis in the leaves of willow, sea buckthorn, and coltsfoot was revealed for the maximum heavy metal content in soils. On plots adjacent to the Unal tailing dump, the contents of pigments and their proportions in leaves of coltsfoot, dandelion, and willow do not differ from those in less contaminated areas. On technogenic plots, the species richness of plants decreases, as well as the mowed biomass and projective cover of herbaceous plants (to 40%); inhibition of plant growth, chlorosis, necrosis, and lamina deformation are observed. A new metallophyte species (Cladochaeta candidissima M. Bieb.) was revealed. The increase in lead and arsenic contents in soils and plants of the Ardon floodplain is accompanied by an increase in their concentrations in the blood and hair of animals. 相似文献
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997.
The geodynamic nature of the Late Neoproterozoic island-arc dacites (691 ± 8.8 Ma) and rift basalts (572 ± 6.5 Ma) of the Kiselikhinskaya Formation, Kutukasskaya Group, in the Isakovskii terrane is inferred from geochemical data and U–Pb zircon (SHRIMP-II) dates. The volcanic rocks were produced during the late evolutionary history of the Yenisei Range, starting at the origin of oceanic crustal fragments and their accretion to the Siberian craton to the postaccretionary crustal extension and the onset of the Caledonian orogenesis. The reproduced sequence of geological processes marks the early evolution of the Paleo- Asian Ocean in its junction zone with the Siberian craton. The data refine the composition and age of volcanic rocks in the trans-Angara part of the Yenisei Range and specifics of the Neoproterozoic evolution of the Sayan–Yenisei accretionary belt. 相似文献
998.
The standard enthalpy of formation of stannite (Cu2FeSnS4) was calculated from the calorimetric measurements of the reactions of its formation from simple synthetic sulfides: Cu2S + FeS2 + SnS → Cu2FeSnS4 and 2CuS + FeS + SnS → Cu2FeSnS4. Using published data for the binary sulfides, the standard enthalpy of formation of stannite from the elements was determined as ΔfH°298.15(Cu2FeSnS4) =–(417.28 ± 2.28) kJ mol–1. 相似文献
999.
M. S. Sreekala Sarah John Sareen Sivalingam Rajathi 《Journal of the Geological Society of India》2018,91(5):621-626
Geo-environmental studies in parts of Ernakulam district (Kerala, India) were carried out. The study area comprises of sedimentary (Limestone, sandstone, Clay and Lignite) and crystalline (Charnockite and gneisses) rocks. The sedimentary terrain is characterized by confined and unconfined aquifers. In hard crystalline formations groundwater occurs under phreatic conditions in the shallow weathered portions and under semi confined to confined conditions in the deep-seated fractures. The study area is demarcated into five areas based on soil types. Climate is hot humid to hot summer with heavily raining monsoon. Two major rivers Periyar and Muvattupuzha drain through the area. Agricultural and industrial activities are prevalent in Ernakulam district. The major cause of pollution in the study area is due to the presence of coliforms. Detailed investigations carried out to identify the coliforms indicated spatial and seasonal changes in the distribution pattern. Monsoon and post monsoon showed significantly high total coliforms compared to pre-monsoon. Thermo-tolerant coliforms is high during monsoon season. This seasonal change could be due to the effect of rainfall, overland flow, nutrient load and temperature change. Wide variations in the coliform counts are observed in wells situated near rivers, canals, paddy fields and in water bodies lying close to pilgrimage center, fertilizer industry, and public places. It is noticed that the chemical characteristics of the groundwater influence the coliform survival. pH, nitrite, bicarbonate, hardness, and alkalinity play a significant role in controlling coliform count. At the outset, the study highlighted the impact of anthropogenic activities on ground water in a coastal district of Kerala state. 相似文献
1000.
S. G. Viladkar 《Journal of the Geological Society of India》2018,92(2):141-144
In the Amba Dongar diatreme, “ferrocarbonatite” is not a single unit of late differentiate of calciocarbonatite magma but it is a family with variation on field occurrence, mineralogy and chemistry of each unit. The family includes dikes of ankeritic carbonatites (phase I and II), plugs of ankeritic carbonatite within sövite ring dike, dikes of sideritic carbonatite in ankeritic carbonatite plug and rödberg veins. Their intrusive relations are very clear in the field and each phase has characteristic mineralogy and trace and REE geochemistry. According to the nomenclature suggested by Harmer and Gittins (1997) majority of “ferrocarbonatites” of Amba Dongar plot in field of “ferruginous calciocarbonatite” and only siderite and rödberg plot in the field of “ferrocarbonatite”. Within these family members, their trace and REE show clear increase from early phase to last phase of sideritic carbonatite. The present short communication discusses various aspects of “ferrocarbonatites”. 相似文献