THE CORRELATION OF LIMESTONE PHYSICAL/MECHANICAL PROPERTIES AND KARST GEOMORPHOLOGY, KARANGASEM AREA, PALIYAN DISTRICT, GUNUNGKIDUL REGENCY, INDONESIA

Karangasem Village, Paliyan District, Gunungkidul Regency, Indonesia is located in the Gunungsewu area, which has been designated as a Global Geopark by UNESCO (UGG = Unesco Global Geopark). This village has an interesting natural landscape, in the form of karst geomorphology which is reflected in the presence of dome and conical hills, dolines, uvala, locva, and caves, which can be promoted as one of the geosites in the Gunungsewu geopark. One aspect of a geopark is science. Thus, geomorphology in the Karangasem area needs to be elaborated from a scientific perspective. The aim of this study is to characterize the relationship between geomorphology and limestone physical/mechanical properties that make up this landform. The methods applied are surface mapping, geomorphological and petrological assessment, physical/mechanical properties testing, and correlation analysis. The research results show that there are three units of lithology, namely reef limestone unit, bedded limestone unit, and marl unit. The three rock units are characterized by their different values of unified compressive strength (UCS), Schmidt hammer hardness, and Mohs scale hardness. Landforms of the study area can be classified into karst hills, karst undulating, and karst plain. This geomorphology is very strong correlated with physical/mechanical properties and lithological units, with correlation coefficient (R-2) > 0.9. The strong, hard, and resistant rocks form rough relief, while weak, soft, and not resistant rocks produce smooth relief.