Mineralogical and geochemical characterization of the Wonosari formation limestone at Gunungkidul Indonesia as preliminary investigation of Portland cement raw material

Abstract

Mineralogical and geochemical investigations were carried out to determine the characteristics of limestone in the Wonosari Formation and to suggest its depositional environment and a preliminary study for the properties of Portland Cement. The study was conducted at Ponjong Area, Gunungkidul Regency, Daerah Istimewa Yogyakarta, Indonesia. The outcrop in this study area is composed of Wonosari layered limestone. Based on the facies interpretation in the research area, there are three depositional units: packstone, wackstone, and grainstone. This area’s depositional environment is the back reef lagoon and sand apron zones that are not related to the open sea. According to XRF data, limestone showed a reasonably high composition of CaO compounds, about 53.78% - 59.09%. Most limestone samples were classified as good quality as Portland Cement Raw Material due to CaO content >49%. The MgO, SiO2, Al2O3, Fe2O3, SO3, K2O, Na2O, TiO2, and P2O5 compounds also fulfil the Indonesian National Standard (SNI-15-2049-2004). Geochemical content shows limestone has a higher grain percentage than the matrix. The utilization of limestone in research area are expected to be a reference for the development of natural resources in the future that pay attention to the environment for mutual sustainability.