Physical and Chemically Changes in Limestone Intruded by Trachytic Dyke: Implications for Cement Raw Material Ulva Ria Irfan (a*), A. M. Imran (a), M. Nur Asyikin Abbas (b)
a) Geological Engineering Department, Faculty of Engineering, Universitas Hasanuddin, Gowa 92119, South Sulawesi, Indonesia.
*ulvairfan[at]yahoo.com
b) PT. Vale Indonesia Tbk., Sorowako, South Sulawesi, Indonesia
Abstract
The objective of this study to analyze the physical and chemical changes in limestone intruded by a trachytic dike, which is used as a raw material for cement. Limestone around the Poloe area, Pangkep Regency, South Sulawesi Province, Indonesia, has been used as raw material for cement. The research method was carried out by observed at the physical changes of limestone from intrusion contact every five meters so that there was invisible effect of the intrusion. Analysis of mineral and geochemical composition of rock samples used petrographic and XRF (X-Ray Fluorescence) methods. Field observations show a gradation of color difference from intrusion contacts in reddish-gray, gray to grayish-white at a distance of 70 meters from the intrusion contact. Microscopically, it shows distinction in grain size smoothing the limestone to the area of influence at a distance of 0 to 5 meters, and on a rock, contact indicate metasomatism in the limestone at a distance of 0 - 5 meters which forming garnet and wollastonite. Limestone shows a decreasing trend in degree of CaO2, Fe2O3, and an increase in SiO2, Al2O3, and MgO towards the intrusion contact. Based on the level of saturation, limestone in the study area can be used as raw material for cement. While the corresponding chemical composition of limestone constituents, a recommended distance of 5 - 70 meters from the intrusion contact.
