CLASSIFICATION OF GEOLOGICAL CONDITIONS USING GEOSTATISTICS IN COAL FIELD, SANGATTA, EAST KALIMANTAN, INDONESIA

Coal deposits at different locations with various geological conditions, have distinct continuity and level of data density. Thus, the justification descriptive within the classification does not depict actual data conditions. It is therefore necessary to justify density level data using geostatistical classification quantitatively. Quantitative classification is taking into account the spatial variability of the data to quantify the level of data density by calculating the value of the variogram range (data geometry and quality of coal). Sangatta coal field area is divided into two zones, the western and the eastern zone. Based on the qualitative analysis of geology, west zone is classified into moderate geological conditions and the eastern zone is classified into complex geological conditions. Based on the analysis of the variogram, kriging and kriging variance, it is known that the west zone of coalfield Sangatta has the geological conditions of moderate (based on SNI 5015, 2011), with a classification category coal resources that, inferred, Indicated and measured, while the eastern zone has geological conditions are complex (based on SNI 5015, 2011), with the coal resource classification categories, Indicated and inferred