Botanical microremains in lithic artifacts from the site of Lapa do Santo (LAGOA Santa, Minas Gerais)

Author(s)

Daniela Dias Ortega

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Museu de Arqueologia e Etnologia (MAE)
• Defense date: 2019-06-25

Examining board members

Ximena Suarez Villagran; Walter Alves Neves; Rita Scheel Ybert

• Advisor: Ximena Suarez Villagran; Célia Helena Cezar Boyadjian

Abstract

The karstic region of Lagoa Santa (Minas Gerais state) contains several archaeological sites dating back to the early Holocene with an astonishing number of well-preserved human remains. The Lapa do Santo rockshelter site, in the northern part of the karst, contains more than 30 human interments in which complex funerary rituals were identified, including defleshing, decapitation and intentional teeth removal. The sedimentary matrix containing the skeletal remains is mostly made of ashes from ancient combustion structures, lit within a period of about 3000 years. Several lithic artifacts have been recovered from the site, most of them of small dimensions (length around 22 mm). Lithics are mostly flakes (rarely retouched), cores and splinters made from single crystals of hyaline quartz. Previous technological research suggests that lithic artifacts were used to cut and scrape small and soft materials, like plants. To verify whether the lithics from Lapa do Santo were indeed used to process plant resources, analyses of plant microremains (phytoliths and starch) were undertaken in 20 artifacts from the site. The artifacts were recovered from three different excavation units (1 m x 1 m) and one interment, following a specific protocol to prevent contamination during collection. Sediment samples from the site were also analyzed in order to differentiate between microremains retained in the lithics after their use or incorporated later from the surrounding sediments. The analyses revealed a larger amount of phytoliths in the lithics (19 of them) and sediment (all samples) and starch in most of the artifacts (16 of them) and in one sediment sample. The identified phytolith morphotypes are diagnostic of the following plant taxa: Aristidoideae, Bambusoideae, Chloridoideae, Arecaceae, Poaceae, including Panicoideae and among these, Zea mays (corn), Cyperaceae, including Cyperus/Kyllinga sp; Zingiberales and Eudicots. The starch grains show resemblances (even though not completely sometimes) to those belonging to: Araceae, Arecaceae, Poaceae, including wild grasses and Zea mays, Ipomoea batatas, Capsicum sp. and Dioscorea sp. The results indicate that the instruments were used to process raw (non cooked) starchy plants. Almost every phytolith from the N23 excavation unit that are present in lithics, are also present in the sediment from this unit (except the ones of Cyperaceae, present in lithic but not in the sediment), which strongly suggest contamination of the lithics with the phytoliths and starch from the sediment. From the P11 excavation unit there are phytolithis of two plant taxa (Aristidoideae and Zingiberales) in the lithics that are not present in the sediment. From the AE1 excavation unit there are phytoliths from four plant taxa (Bambusoideae, Chloridoideae, Cyperus/Kyllinga sp. and Zingiberales) in the lithics that are not present in the sediment. This suggests that the phytoliths in these artifacts may have been originated by their use and not by contamination with the sediment. (AU)

• FAPESP's process: 17/01769-7 - Botanical Microtraces in lithic artifacts of the Lapa do Santo site (Lagoa Santa, Minas Gerais)
• Grantee: Daniela Dias Ortega
• Support Opportunities: Scholarships in Brazil - Master