Abstract
The interesting concern in this study is that in the same outcrop it was found that the first coal seam (coal seam-D) contains silicified coal and the second coal seam (coal seam-E) does not contain silicified coal and how to find out the cause. In general, the characteristics of silicified coal seam-D are in the form of lenses; the distribution extends from a few meters to several tens of meters with a thickness of three to five centimeters and some are in nodules. Environmental conditions are the main factor in the formation of silicified coal where the acidity level of coal bearing sediment seam-D which is between 3.4 (roof sediment) to 4.2 (floor sediment) is higher than coal bearing sediment seam-E which has a pH of 5.4. This condition indicates that the coal bearing sediment seam-D environment is more acidic than coal seam-E. The results of XRD analysis show that the seam-D containing silicified coal has a composition of 47.47% kaolinite, 21.27% illite, 23.73% smectite and 17.54% mixed layer, while the seam-E which does not contain silicified coal has a composition of kaolinite 35.78%, illite 17.88%, smectite 21.59% and mixed layer 24.76%. Acidic environmental conditions (pH) and silica enrichment in clay minerals (kaolinite) in the roof sediments during sedimentation, accelerated the process of deposition of colloidal silica in the wood structure of coal seams into silicified coal.
Highlights
The research is located in PIT “x”, Tanjung area, Tabalong Regency, South Kalimantan which is geologically included in the Barito Basin
The stratigraphy of research area is composed of the Warukin Formation which was deposited during the Middle Miocene to the Late Miocene (Satyana et al, 1994)
1) Roof sediment seam-D is a layer of research coal seam, coal containing silicifiedcoal, lithology of carbonic claystone from the results of X-ray diffraction (XRD) analysis it is written that the composition clay minerals of the carbonaceous claystone is kaolinite (47.47%), illite (21.27%), smectite (13.73%) and mixed layer (17.54%)
Summary
The research is located in PIT “x”, Tanjung area, Tabalong Regency, South Kalimantan which is geologically included in the Barito Basin. The stratigraphy of research area is composed of the Warukin Formation which was deposited during the Middle Miocene to the Late Miocene (Satyana et al, 1994). There are boulders and inserts of silica minerals (silicified coal). Genesa or the process of forming silicified coal according to (Sigleo, 1978) and occurs due to the leaching process of the roof sedimentary rocks which contain high silica. The roof sedimentary rock layer with carbonaceous claystone lithology must be carried out with an X-ray diffraction (XRD) clay oriented analysis to identify the clay mineral composition which influences the formation of silicified coal
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
