Ochre Geochemistry Poster Awarded Prize at the SAAs

Today we learned that the Society for Archaeological Sciences awarded Andrew Zipkin, Alison Brooks, John Hanchar, Jessica Thompson, and Elizabeth Gomani-Chindebvu the R.E. Taylor Student Poster Award for Zipkin’s presentation of the poster “On the formation and distribution of ochreous minerals in northern Malawi” during the Geoarchaeology Session of last week’s SAA annual meeting.

According to the SAS website, “This prestigious award is named in honor of Professor Emeritus R. Ervin Taylor of the University of California at Riverside for his outstanding contributions in the development and application of radiocarbon dating in archaeological research and dedication to the founding of the Society for Archaeological Sciences, for his leading role as President (1980) and General Secretary (1981-2002) and his committed service as editor of the SAS Bulletin.”

The MEMSAP team members and collaborators who contributed to this poster are honored to receive the Taylor award from the SAS and thank them for their support and recognition.  An updated abstract based on the poster is copied below for those who want to get a preview of this work before it is submitted for publication.

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On the formation and distribution of ochreous minerals in northern Malawi

Andrew M. Zipkin1,2, Alison S. Brooks2,3, John M. Hanchar4, Jessica C. Thompson5, and Elizabeth Gomani-Chindebvu6

1.Hominid Paleobiology Doctoral Program, 2. Center for the Advanced Study of Hominid Paleobiology, Department of Anthropology, The George Washington University, 3. Human Origins Program, National Museum of Natural History, Smithsonian Institution, 4. Department of Earth Sciences, Memorial University of Newfoundland, 5. School of Social Science, University of Queensland, 6. Malawi Ministry of Tourism, Wildlife, and Culture

J. Desmond Clark and colleagues’ Middle Stone Age excavation at Chaminade 1A, Karonga, Malawi during the 1960s yielded utilized ochre artefacts indicative of pigment processing activities.  Our 2011 survey of northern Malawi ochre deposits suggested that many potential pigment sources are difficult-to-characterize, sedimentary rocks containing detrital minerals from diverse parent rocks.  Here we report a new comparative study of three approaches to ochre provenance geochemistry.  Instrumental Neutron Activation Analysis (INAA) and two variants of Laser Ablation – Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS: 1. Bulk Ochre “Paint Chip” Ablation and 2. Zircon Crystal Ablation) were applied to Malawian ochre source samples in order to test the Provenance Postulate and identify the minimum sample mass required for reliable characterization.  Our results indicate that while INAA is suitable for relatively homogeneous ochre sources, “Paint Chip” LA-ICP-MS is capable of effectively distinguishing amongst multiple heterogeneous ochre deposits.  In addition, zircon crystals have been extracted from ochre and ablated successfully for the first time, raising the possibility of routinely conducting trace element analysis on heavy minerals in ochre and dating the formation of ochre parent rocks.  A provenance study of the Chaminade 1A ochre assemblage using LA-ICP-MS is warranted in order to investigate preferential mineral resource exploitation and transport distances.

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