Characterization of Filler Cement and Columnar Joint Rocks of Prehistoric Megalithic Site Gunung Padang West Java
Bagus Endar B. Nurhandoko, Andri S. Subandrio, Danny Hilman Natawidjaja, Andang Bachtiar, Ali Akbar, Mudrik Daryono, Yusuf Maulana, Budianto Ontowirjo, Pon Purajatnika, Andi Krisyunianto, Taqiyudin, Ratih Pratiwi, Maria Cindrawati

Bandung Institute of Technology, National Research and Innovation Agency, GDA consulting, University of Indonesia, Padjadjaran University, Rock Fluid Imaging Lab

Abstract

Gunung Padang is a prehistoric megalithic site in Karyamukti village, Cianjur, West Java, Indonesia. This site currently attracts the attention of many people from geoscience perspectives and archaeologists.
We investigated the constituent material of this prehistoric megalithic site of Gunung Padang, Cianjur, West Java, which consists of piles of columnar joints and filler material on the sidelines of the columnar joint rock arrangement.
The rock samples were collected directly from the Gunung Padang megalithic site. We collected some grams of filler material and columnar joint rock. Then, we meticulously treated these rocks and characterized them using an X-ray diffractometer (XRD) Bruker D8 Advance. The results revealed that the columnar joint rocks were predominantly composed of Plagioclase and Feldspar, while the filler material consisted mainly of Quartz, Kaolinite, Smectite, and Muscovite minerals.
The mineralogical composition of the filler material shows that it was formed from hydrothermal products in an acidic environment. The filler materials were likely transported from another location to construct the megalithic site at Gunung Padang. However, the columnar joints at the site originated from basaltic intrusion rock. Therefore, the laboratory measurements indicated the distinct sources of these two rock types, which implies the past construction history of the Gunung Padang megalithic site.

Keywords: Gunung Padang, Prehistoric Megalithic site, Rock Characterization, Columnar Joint, Filler cement

Topic: Interdisciplinary Earth Science and Technology