Aspen Greaves
Phytoliths are inorganic opal silica bodies produced by many plant families, sometimes forming species-distinct shapes that remain after the decay of organic tissues. Because of a high rate of preservation, phytolith samples are useful for identifying taxa not represented in macrobotanical assemblages, especially wild taxa (Piperno 2006). They can also correspond with different parts of the plant, which is useful for identifying processing activities. Both macrobotanical and phytolith identification have been crucial in identifying pastoralist use of wild and domestic plants (Lu et al. 2009; Shahack-Gross et al. 2003, 2004). Species collected during the 2024 TVP collection were processed for phytolith recovery in the Arlene Rosen Lab for Geoarchaeology at the University of Texas, Austin.
Processing modern samples differs from processing soil sample from archaeological or other contexts. Processing for this collection was done as follows:
1. Preliminary combustion of samples was conducted in situ in Mongolia. Upon access to laboratory facilities, specimens underwent complete ashing in a muffle furnace at 500°C for 2 hours. In instances where residual carbonate material exceeded acceptable levels, the ashing protocol was repeated.
2. Once ashed completely, a 10% hydrochloric acid (HCl) solution was added to each specimen to facilitate dissolution of calcium carbonate compounds. They are then washed with reverse osmosis (RO) purified water, followed by centrifugation at 2,000 revolutions per minute (rpm) for 5 minutes to remove residual acidic solution. This cycle was only applied once in this case to retain scarce material, although typically may be applied multiple times.
3. Samples were carefully transferred to small beakers to dry by evaporation in a 45°C oven. Following complete desiccation, samples were affixed to glass microscope slides using appropriate mounting medium and permitted to undergo secondary drying.
Citations
International Committee for Phytolith Taxonomy (ICPT). 2019. International Code for Phytolith Nomenclature (ICPN) 2.0. Annals of Botany 124(2):189–199. https://doi.org/10.1093/aob/mcz064.
Lu, Houyuan, Jianping Zhang, Kam-biu Liu, Naiqin Wu, Yumei Li, Kunshu Zhou, Maolin Ye, et al. 2009. Earliest Domestication of Common Millet (Panicum Miliaceum) in East Asia Extended to 10,000 Years Ago. Proceedings of the National Academy of Sciences of the United States of America 106(18):7367–7372.
Piperno, Dolores R. 2006. Phytoliths: A Comprehensive Guide for Archaeologists and Paleoecologists. Rowman Altamira.
Shahack-Gross, Ruth, Fiona Marshall, Kathleen Ryan, and Steve Weiner. 2004. Reconstruction of Spatial Organization in Abandoned Maasai Settlements: Implications for Site Structure in the Pastoral Neolithic of East Africa. Journal of Archaeological Science 31:1395–1411. https://doi.org/10.1016/j.jas.2004.03.003.
Shahack-Gross, Ruth, Fiona Marshall, and Steve Weiner. 2003. Geo-Ethnoarchaeology of Pastoral Sites: The Identification of Livestock Enclosures in Abandoned Maasai Settlements. Journal of Archaeological Science 30(4):439–459. https://doi.org/10.1006/jasc.2002.0853.
Vos, Daniella, Emma Jenkins, and Carol Palmer. 2018. A Dual Geochemical-Phytolith Methodology for Studying Activity Areas in Ephemeral Sites: Insights from an Ethnographic Case Study from Jordan. Geoarchaeology 33(6):680–694. https://doi.org/10.1002/gea.21685.
Reference Collection 