Lithofacies Analysis and Architectural Elements of Interbedded of Carbonate Sandstone and Carbonate Mudstone in the Kerek Formation in the Kauman and Surrounding Areas of Wonosegoro District, Boyolali Regency, Central Java Province

A study was conducted on the lithofacies and architectural elements of interbedded carbonate sandstone and carbonate mudstone of the Kerek Formation in the Kauman area and surroundings, Wonosegoro District, Boyolali Regency, Central Java. The research aimed to determine the characteristics of sedimentation processes, facies, facies associations, and the depositional environment of the area. Sedimentation was controlled by two main processes: mass transport deposits (MTD) and turbidite currents, expressed as slumps and Bouma sequence intervals (Ta–Te). Nine lithofacies were identified, including pebbly sandstone, massive sandstone, bedded sandstone, parallel-laminated sandstone, wavy/convoluted/cross-laminated sandstone, sandstone–mudstone interbeds, massive mudstone, sandstone–siltstone interbeds, and slump deposits. Six facies associations were recognized: distal levee, silty–sandy distal lobes, sandy lobes, mud-filled channels, distributary channels, and mid-fan/slope channels. The facies model corresponds to classical turbidites (CT), massive sandstones (MS), and pebble sandstones (PS), indicating deposition in a submarine fan system, specifically in the middle-fan setting within the channelized to smooth portions of suprafan lobes.