Shiny grooved surfaces: the case study of the Skiles rockshelter, Lower Pecos, Texas


Shiny grooved surfaces are common in rock shelters and cave sites in the Lower Pecos region, Texas. They are found on horizontal as well as vertical exposures, usually in close association with mortars and/or rock art. The shiny appearance has been interpreted as the result of human traffic, hand touching, animal sacrifice, etc. In many cases these surfaces are densely grooved and incised by a variety of shallow and deep marks which are not found outside the shiny surface. Such phenomena have scarcely been analyzed in detail, in spite of their central location within many sites and their assumed social/ceremonial importance.

The aim of this paper is to present a new analytical protocol based on Structure from Motion photogrammetry, high-resolution 3D models and spatial analysis. We use one case study from the Lower Pecos (Texas) and focus on the location, context and characteristics of the shiny surface, background noise, associated features (mortars), microscopic residues, and especially the grooves and incisions. These are characterized in terms of dimensions, cross-section, location, orientation, production and use signs. Their spatial clustering and super-imposition are studied in detail. The results provide new insights into the utilization history of the surface and suggest possible interpretations.

SAA 2015 abstracts made available in tDAR courtesy of the Society for American Archaeology and Center for Digital Antiquity Collaborative Program to improve digital data in archaeology. If you are the author of this presentation you may upload your paper, poster, presentation, or associated data (up to 3 files/30MB) for free. Please visit for instructions and more information.

Cite this Record

Shiny grooved surfaces: the case study of the Skiles rockshelter, Lower Pecos, Texas. Eli Crater Gershtein, Steve Black, Amanda Castaneda, Tammy Boanasera, Daniel Nadel. Presented at The 80th Annual Meeting of the Society for American Archaeology, San Francisco, California. 2015 ( tDAR id: 395194)