Formation of the Ngandong Paleoanthropological Site and Solo River Terrace Sequence, Central Java, Indonesia
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University of Iowa Iowa Research Online Theses and Dissertations Spring 2018 Formation of the Ngandong paleoanthropological site and Solo River terrace sequence, Central Java, Indonesia Maija Eliina Sipola University of Iowa Follow this and additional works at: https://ir.uiowa.edu/etd Part of the Geology Commons Copyright © 2018 Maija Eliina Sipola This dissertation is available at Iowa Research Online: https://ir.uiowa.edu/etd/6286 Recommended Citation Sipola, Maija Eliina. "Formation of the Ngandong paleoanthropological site and Solo River terrace sequence, Central Java, Indonesia." PhD (Doctor of Philosophy) thesis, University of Iowa, 2018. https://doi.org/10.17077/etd.7l1okwsy Follow this and additional works at: https://ir.uiowa.edu/etd Part of the Geology Commons FORMATION OF THE NGANDONG PALEOANTHROPOLOGICAL SITE AND SOLO RIVER TERRACE SEQUENCE, CENTRAL JAVA, INDONESIA by Maija Eliina Sipola A thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in Geoscience in the Graduate College of The University of Iowa May 2018 Thesis Supervisor: Professor E. Arthur Bettis, III Copyright by MAIJA ELIINA SIPOLA 2018 All Rights Reserved Graduate College The University of Iowa Iowa City, Iowa CERTIFICATE OF APPROVAL ______________________________ PH.D. THESIS ________________ This is to certify that the Ph.D. thesis of Maija Eliina Sipola has been approved by the Examining Committee for the thesis requirement for the Doctor of Philosophy degree in Geoscience at the May 2018 graduation. Thesis Committee: ____________________________________ E. Arthur Bettis, III, Thesis Supervisor ______________________________________ Russell Ciochon ______________________________________ Jeffrey Dorale ______________________________________ Emily Finzel ______________________________________ Mark Reagan To my friends, family, and teachers ii A computer is not a washing machine in which our data can be purified. A.M. Winkelmoen, 1982 iii ACKNOWLEDGEMENTS I would like to thank my wonderful parents for their sacrifice and continued support, my dear friends Lisa, Kat, Gina, Abby, Neo, Alissa, and Allison for their support and friendship, my thesis advisor, Art Bettis, and my committee members for their advice, encouragement, and patience throughout my PhD program, and all of my teachers and professors who have helped me work to reach my potential throughout my 29 years of formal education. I would also like to acknowledge my generous funding sources for supporting this project: the University of Iowa Department of Earth and Environmental Sciences, Geological Society of America, National Science Foundation, Australian Academy of Science, Wenner- Gren Foundation, Center for Global and Regional Environmental Research, and the University of Iowa Graduate and Professional Student Government (formerly Executive Council of Graduate and Professional Students). I would also like to acknowledge Porkchop, Judith Schorsch, Robyn, Sigur Ros, and Pam Schwartz, all of whom helped me keep moving forward throughout this project. iv ABSTRACT The Ngandong paleoanthropological site in Central Java, Indonesia has significant impact on the models for human migration and evolution out of the African continent. Located on a Late Pleistocene fluvial terrace along the Solo River, paleoanthropological excavations at Ngandong have uncovered fourteen Homo erectus fossils that, based on their position at a low terrace level and preliminary ages produced by uranium-series dating, are believed to be possibly the most recent known occurrences of H. erectus in the world. However, this hypothesis cannot be substantiated by the results of previous studies at Ngandong due to a general scarcity of geologic knowledge of the Solo River terrace sequence formation. This study seeks to overcome the limits of these previous studies by taking a comprehensive, geoarchaeological approach to this paleoanthropological site by pairing sedimentary, mineralogical and geochemical analyses with luminescence dating techniques to understand the timing and mechanics of the Ngandong site formation. The results of these analyses suggest the Ngandong terrace deposits and fossils within were deposited within a Solo River paleochannel over a relatively short period of time, and were largely sourced from the volcanic arc to the south, with the exception of a fine-grained mudflow layer derived mainly from local carbonate bedrock in the Kendeng Zone. v PUBLIC ABSTRACT The early human paleoanthropological site at Ngandong, Central Java, Indonesia has significant impact on the models for human migration and evolution out of the African continent. Located on an abandoned stream bank above the Solo River, Ngandong archaeological digs have uncovered fourteen Homo erectus fossils that, based on their unique shape, are believed to have lived more recently than any other known examples of Homo erectus. However, this hypothesis has not been substantiated by previous studies at Ngandong due to a general lack of understanding about the formation of the site as a whole. This study seeks to overcome the limits of these previous studies by thoroughly examining the grain size, grain shape, mineralogy, geochemistry, and stratigraphy of the site to understand how it formed, and in turn, provide a necessary geological context to the Ngandong Homo erectus fossils. The results outlined in this dissertation suggest the fossil-bearing layers were deposited at the site (at the time a channel bottom) over a short period of time and were sourced from the volcanic arc that forms the southern portion of Java island. vi TABLE OF CONTENTS LIST OF TABLES ............................................................................................................. ix LIST OF FIGURES .............................................................................................................x CHAPTER I: INTRODUCTION TO NGANDONG SITE AND JUSTIFICATION FOR STUDY METHODS .........................................................................................1 Introduction .......................................................................................................1 Background .......................................................................................................2 Paleoanthropological Background .............................................................2 Geological Background: Java and the Kendeng Zone...............................6 Fluvial Terrace Formation .......................................................................15 Dating the Ngandong Site Stratigraphy ...................................................18 Research Objectives ........................................................................................22 Explanation and Justification of Research Methods .......................................23 Field Methods ..........................................................................................23 Laboratory Methods ................................................................................25 Grain-Shape Analysis ..............................................................................36 Mineralogical and Geochemical Characterization ..................................37 Conclusion ......................................................................................................39 CHAPTER II: FORMATION OF THE NGANDONG SITE STRATIGRAPHY ............40 Abstract ...........................................................................................................40 Introduction .....................................................................................................41 Geologic Background ..............................................................................41 Paleoanthropological Background ...........................................................43 Methods ..........................................................................................................44 Field Excavation ......................................................................................44 Grain Size and Grain Shape Analyses .....................................................45 Results.............................................................................................................52 Stratigraphy .............................................................................................52 Grain Shape Analysis ..............................................................................69 Grain Size Analysis .................................................................................69 Interpretation ...................................................................................................84 Descriptive Facies Overview ...................................................................84 Interpretive Sedimentary Facies ..............................................................85 Discussion .......................................................................................................90 Conclusion ......................................................................................................92 CHAPTER III: LUMINESCENCE DATING OF VOLCANICLASTIC FLUVIAL SEDIMENTS OF THE SOLO RIVER TERRACE SEQUENCE AT NGANDONG IN EAST JAVA, INDONESIA ..............................................94 Abstract ...........................................................................................................94 Introduction .....................................................................................................95