Limestone Deposits and Its Economic Importance at Panchbibi Area of Joypurhat District, Bangladesh

摘要

The study area is located at Panchbibi upazila of Joypurhat District which is in the south-western part of Bangladesh. Tectonically the area lies in the southern slope of Rangpur saddle within the stable Precambrian platform. The investigation work carried out by an exploratory drilling operation with the help of wire line drilling rig. Core samples were collected and subsequently analyzed during the drilling activity. Three limestone layers have been encountered at different depth of this drilling hole which is in between 450 meter to 530 meter below the surface. This limestone is light grey in colour, fossiliferous, sandy in nature, moderately hard and compacted. The outer surfaces of core samples are not smooth. It Composed of mainly (&40%) calcium carbonate (CaCOsub3/sub). The average chemical property of limestone is 44% CaO, 10% SiOsub2/sub, 1% Fesub2/subOsub3/sub and 2% Alsub2/subOsub3/sub. The thickness of limestone is varies from layer to layer where first layer is about 8 m thick and the total thickness of the limestone is about 13 m. The physical and chemical properties of limestone indicated that the quality of limestone is medium to good. Composed of calcareous sands, both skeletal and oolitic, with lesser volume of fine carbonate mud and reef rocks which indicated that the condition of deposition of this limestone is shallow water deposits. It is the most important and widely distributed carbonate rocks which used in many industrial purposes. The limestone deposit of the studied area may utilize at different purposes after extraction like as mainly in manufactures of cement clinkers in the cement factory. Besides it is also used as different construction materials. It should be suggested that more exploratory drilling hole detail geophysical investigation might be done to evaluate the real picture of this deposits.