Estimating the equivalent dose of late Pleistocene fine silt quartz from the Lower Mississippi Valley using a standardized OSL growth curve

The establishment of a standardized growth curve is desired for optical dating as it facilitates the dating procedures. Here, we analyzed the dose responses of 16 fine silt quartz samples from the Lower Mississippi Valley in order to identify common properties that would allow establishing a standardized OSL growth curve (SGC). The analysis confirms the dependence of the standardized dose response upon the size of test dose. This dependence was corrected by converting the standardized dose response to an equivalent standardized dose response obtained by a 1.8 Gy test dose. Equivalent SGCs were established for two different grain size ranges by combining the data of several samples and fitting the sum of a single saturating exponential function and a linear function to the equivalent standardized dose response of these data. Equivalent doses up to 500 Gy determined with an equivalent SGC agree well with those obtained with a conventional SAR protocol, suggesting that the equivalent SGCs established in this study are reliable.