31 Archaeological Geology, Paleoclimate, and Geomorphology (Posters)

Friday, 31 March 2017
1:00 PM - 5:00 PM
James River Ballroom

BRINGING THE MID-ATLANTIC REGION TO THE LIGHT: A SUMMARY OF PUBLISHED LUMINESCENCE AGES (OSL, IRSL, TL) FROM THE AREA, WHAT WE HAVE LEARNED AND NEW UTILITIES OF THE TECHNIQUE IN REGIONAL GEOMORPHOLOGY AND ARCHAEOLOGY

Paper number: 31-8
Program: Technical Sessions
Time: 1:00 PM – 5:00 PM

Authors

Abstract

Luminescence dating can be applied to sand and silt-sized particles in a variety of Quaternary deposits, and provides an age estimate of the last time sedimentary quartz and feldspar were exposed to light or heat. While complimentary to radiocarbon and cosmogenic nuclide dating, it requires no organic material, is minimally influenced by subsequent erosion, and it can measure ages beyond the limit of radiocarbon and below the typical limit with cosmogenic exposure dating. Optically stimulated luminescence (OSL) dating of quartz ranges from ~100 to ~200,000 years, similar to thermoluminescence (TL) dating, while infrared (IRSL) dating on potassium rich feldspar can produce reliable ages as old as 200,000-400,000 years. Publications and applications to geomorphic and archaeologic settings has grown exponentially in the past decade worldwide, with a notable outpouring of interest within the U.S. in the last decade. While a handful of studies in the Mid-Atlantic States have more recently (<5 yrs) employed luminescence dating, the technique has yet to be fully utilized in the region compared to the wealth of ages generated from deposits in the western U.S.

We present a review of the past applications of luminescence dating in the Mid-Atlantic region and evaluate ways in which it could be more fully utilized. In addition, we will provide examples of best sampling practices across a variety of geomorphic settings and elaborate on innovative applications of OSL to cultural materials (i.e. pottery). Mainly, luminescence dating has been applied to sandy quartz-rich Coastal Plain sediments east of the Fall Line- escarpment separating the Piedmont uplands from the Coastal Plain. OSL has been particularly useful in dating organic-poor and enigmatic coastal and near-shore deposits, and refining changes in relative sea level over the last glacial cycle (~160ka) (i.e. Lamothe et al., 2012; DeJong et al., 2015). Current research that applies luminescence dating to fluvial terraces and soil stratigraphy is underway, though it is mainly focused in and around the tectonically derived sediments of the central VA seismic zone in the Piedmont (i.e. Carter 2015; Malenda, 2015). Examples and recommendations for sampling will be provided in this presentation along with discussion of what to avoid when collecting samples for OSL/IRSL dating.

Geological Society of America Abstracts with Programs. Vol. 49, No. 3

doi: 10.1130/abs/2017SE-291315

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