MINERALOGICAL CHARACTERIZATION OF SOLO RIVER TERRACE DEPOSITS AT NGANDONG, CENTRAL JAVA, INDONESIA

The Ngandong Homo erectus site in Central Java, Indonesia is of great interest to paleoanthropologists and geoarchaeologists. The morphology of the H. erectus crania first discovered there in the 1930’s suggests those fossils may be of the most recently-living Homo erectus known in the world, yet numerous studies have been unable to confidently date the age of the fossils or the timing of site formation. In addition, thousands of fossils of non-hominin macrofauna have been collected during early excavations of the Ngandong site without a comprehensive geoarchaeological assessment of their relationship to the terrace stratigraphy, preventing an understanding of the depositional processes responsible for site formation. Recently, a thorough excavation of the site was undertaken by a team of Indonesian and American scientists with special focus on documenting and analyzing the site stratigraphy. In this study I summarize the results of a mineralogical analysis of the stratigraphic layers present at the site in an effort to delineate possible depositional facies boundaries based on different sediment sources. I combine these mineralogical data with results of grain-size and grain-shape analyses to characterize the sediment source(s) and depositional conditions that produced the fossil-bearing terrace deposits present at Ngandong. This information improves our understanding of the Solo River fluvial dynamics at the time of site formation and may potentially inform as to the location and condition of other fossil-bearing deposits in the region.