T Rabani; N Taghipour; R Aharipour
Abstract
Gheshlagh district contains coal deposits in a large syncline in Shemshak group sediments in East Alborz. To determine the palaeoenvironmental setting of the coal deposits based on organic and mineral components, eleven samples from coal seams from four active mines are collected. Minerals such as quartz, ...
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Gheshlagh district contains coal deposits in a large syncline in Shemshak group sediments in East Alborz. To determine the palaeoenvironmental setting of the coal deposits based on organic and mineral components, eleven samples from coal seams from four active mines are collected. Minerals such as quartz, kaolinite, pyrite, siderite, biotite, montmorillonite and dolomite are identified in Gheshlagh coal mines. The Ground Water Index (GWI) suggests ombrotrophic hydrological conditions for coal layers in Gheshlagh coal region. K13 and k11 layers have much higher GWI among others due to its higher mineral content than other layers. Vegetation index (VI) of the Gheshlagh coals is less than 3, which could indicative of the dominance of aquatic/herbaceous plants in the formation of coal seams. Petrographic data on organic and inorganic matter with facies diagram suggest evidences of anaerobic to low oxygen, alkaline conditions and variations in water level with relative proximity to the marine environment.
Z Solaymani; N Taghipour; R Aharipour
Abstract
This study investigates the organic petrographic of the upper Triassic to Lower Jurassic Olang coal deposits. Olang area is located in 70 km of northeast Shahroud. This area is situated in Gheshlagh Olang synclinal which is a member of eastern Alborz coal basin. Microscopic studies showed that all three ...
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This study investigates the organic petrographic of the upper Triassic to Lower Jurassic Olang coal deposits. Olang area is located in 70 km of northeast Shahroud. This area is situated in Gheshlagh Olang synclinal which is a member of eastern Alborz coal basin. Microscopic studies showed that all three maceral groups of vitrinite, inertinite and liptinite presented in coal deposits of the Olang region and the vitrinite is most important maceral group in these coals. Macerals of vitrinite group include colotelinite, collodetrinite and corpogelinit that collodetrinite is the most abundant of maceral in coal deposits. All of inertinite macerals group observed in these coals which Semifusinite and fusinite are the most abundant in this group. Spornite, cutinite, resinite and lipthodetrinite macerals of liptinite group are present in the coals. Abundance of collodetrinite, presentation of fnginite and the absence of tellinite in these coals are usually thought to indicate deposition in neutral to weakly alkaline waters in an oxygen-rich environment.
