GEOLOGI SITUS CIOMAS DI KABUPATEN SUKABUMI: KAJIAN SUMBER BATUAN UNTUK BAHAN LITIK

Abstract

Situs terbuka Ciomas mengandung tinggalan budaya dari masa Neolitik. Dalam penelitian arkeologi di situs Ciomas ditemukan litik dari masa Neolitik berupa serpih, mata panah, beliung, dan beliung setengah jadi, yang dibentuk dari batuan chert, jasper, kalsedon, dan batugamping kersikan. Namun demikian, aspek lingkungan geologi situs tersebut belum pernah diteliti secara detail. Tujuan penelitian ini adalah memahami karakteristik geomorfologi, stratigrafi, struktur geologi, dan menentukan lokasi sumber batuan untuk bahan alat-alat Neolitik. Penelitian ini diawali dengan kajian pustaka dan survei lapangan, lalu dilanjutkan dengan analisis petrologi, dan interpretasi data lapangan. Situs Ciomas termasuk ke dalam Zona Pegunungan Selatan Jawa Barat dan kelompok Endapan Vulkanik Pleistosen. Hidrogeologinya termasuk kelulusan rendah sampai sedang. Hasil penelitian ini adalah data tentang bentang alam situs yang terdiri atas morfologi dataran dan bergelombang lemah. Karakteristik sungai di kawasan penelitian memiliki pola trellis dan rectangular, stadia sungai tua, sungai periodik dan sungai episodik. Batuan penyusun kawasan situs Ciomas adalah endapan aluvial, endapan undak tua, andesit, napal, breksi vulkanik, dan tufa. Struktur geologi kawasan ini berupa sesar normal dan antiklin. Berdasarkan data geologis tersebut, dapat disimpulkan lokasi pengambilan bahan baku batuan untuk pembuatan alat-alat litik berasal dari sekitar dataran situs dan di sepanjang Sungai Cikaso yang mengalir melewati situs.The Ciomas open site contains cultural remains from the Neolithic period. Archaeological research here yielded Neolithic tools such as flakes, arrowheads, adzes as well as adze blanks, which were made of chert, jasper, chalcedony, and silicified limestone. However, the environmental aspects of the site's geology have never been studied in detail. The objective of this research is to understand the characteristics of geomorphology, stratigraphy, and geological structure, and determine the location of rock sources for Neolithic tools. This research began with a literature review and field survey, then continued with petrological analysis and interpretation of field data. The Ciomas site falls into the category of the South Mountain of West Java Zone and the Pleistocene Volcanic Deposits Group. The hydrogeology of the site shows low to moderate graduation. The results of this study are data on the site's landscape which consists of plain and weakly undulating morphology. The characteristics of the rivers in the study area have trellis and rectangular patterns, old river stadia, periodic rivers and episodic rivers. The rocks that make up the Ciomas site area are alluvial deposits, old stepped deposits, andesite, marl, volcanic breccia, and tuff. The geological structure of this area consists of normal faults and anticlines. Based on the geological data, it can be inferred that the location of rock materials for lithic-making was procured from around the plains of the site and along the Cikaso River which flows through the site.