QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation.
Assessing Rock Surface Erosion Using Cosmogenic Isotopes and Optically Simulated Luminescence Depth Profiling in Petroglyph Contexts
Abstract: Petroglyphs, rock images created by the anthropogenic removal of material on a rock surface, are subjected to various natural and anthropogenic conditions that cause them to degrade over time and eventually disappear. Accurate quantification of the erosive impacts on petroglyph surfaces and identifying and understanding the environmental factors of erosion can be essential for planning preservation strategies.
A multidisciplinary scientific analysis utilizing geochemical and paleoenvironmental analysis methods at petroglyph bearing sites will be conducted at Henry W. Coe State Park, located in the Diablo Range of Northern California, to assess the history of and factors contributing to rock surface erosion. This analysis will primarily focus on utilizing concentrations of cosmogenic isotope 10Be from rock surface samples in proximity to petroglyphs to establish proximal rock erosion rates to petroglyph surfaces. Using the data, erosion episodicity (whether spallated, gradual, etc.) may also be determined via applied modeling. Cosmogenic erosion data will be co-analyzed with optically simulated luminescence (OSL) depth profiling analyses on similar/same rock surfaces to decipher any unique environmental settings that may impact each method’s results. Providing a cosmogenic-OSL dual analysis also helps introduce cosmogenic isotopes to archaeological study in a way that easily relates cosmogenic isotopic methods to OSL, making it easier to understand and incorporate cosmogenic isotopes in future archaeological work. The same can be said for Earth scientists interested in rock erosion analyses yet are less familiar with OSL, which is an underutilized tool in the Earth Sciences yet hosts great potential for surface process study. No samples directly from petroglyph surfaces will be taken. Additional paleoenvironmental analyses of the petroglyph region will also be carried out, utilizing a multitude of methods such as palynology, rock-vegetation interaction analyses, Landscape Reconstruction Algorithms (LRA), and other relevant paleoenvironmental methods that will be uniquely applicable to the site. Once gathered, a comparative analysis utilizing the quantitative erosion data and paleoenvironmental records will then be conducted to provide a better understanding of the erosive history of petroglyph surfaces and help identify the environmental factors affecting erosion rates. This knowledge may offer needed data for communities and parks wanting to optimize the preservation of their material heritage.
Abstract: Petroglyphs, rock images created by the anthropogenic removal of material on a rock surface, are subjected to various natural and anthropogenic conditions that cause them to degrade over time and eventually disappear. Accurate quantification of the erosive impacts on petroglyph surfaces and identifying and understanding the environmental factors of erosion can be essential for planning preservation strategies.