OSL Characterisation of Two Fluvial Sequences of the River Usmacinta in its Middle Catchment (SE Mexico)

Kinnaird, T. C., Muñoz-Salinas, E., Sanderson, D. C.W. , Castillo Rodriguez, M. and Cruz-Zaragoza, E. (2014) OSL Characterisation of Two Fluvial Sequences of the River Usmacinta in its Middle Catchment (SE Mexico). Technical Report. SUERC, University of Glasgow.

Abstract

The report summarizes luminescence profiling, initially using a SUERC PPSL system in Mexico, and laboratory analysis at SUERC, used to characterise the stratigraphy and interpret sedimentary processes in terrace deposits of the Usumacinta River, SE Mexico. This was then followed, by quantitative quartz OSL SAR dating of five sediment samples, aimed at defining the chronologicalframework of two sedimentary sequences, USU13-1 and USU13-2. In the wider region, the middle catchment of the Usumacinta River, contains numerous archaeological sites dating to the Maya Classic Period, including Bonampak, Yaxchilan and Piedras Negras. The broader aim of the investigation is to assess whether the two fluvial sequences contain a proxy record of environmental change through the archaeological period of interest. Initial luminescence profiling revealed that the stratigraphy in each profile was complex, reflecting multiple cycles of deposition, with signal maxima, followed by tails to lower intensities, possibly indicating deposition during extreme flood events, interleaved with periods of slower sedimentation, and potentially better luminescence resetting. Laboratory profiling reproduced the apparent maxima/trends in the field profiling dataset, confirming that both sections record complex depositional histories. Furthermore, the variations in stored dose estimates, and luminescence sensitivities with depth, confirm that the sections do not record simple age-depth progressions. Quantitative quartz OSL SAR dating was undertaken on five sediment samples. Given the information obtained from the field- and laboratory-profiles it is not surprising that the equivalent dose distributions for each sample showed considerable scatter, particularly so for the second section, USU13-2. Nevertheless, throughstatistical analysis, individual quartz OSL SAR ages were obtained for each sample. Individual dates fall into the Mayan Post-Classical Period to early modern Period, with statistical combinations pointing to a late 15th century accumulation of USU13-1, and the 18th century accumulation of the sediment within USU13-2. Interestingly, the three samples from section USU13-2, all show some aliquots which tail to higher equivalent doses; furthermore, in each sample, the mean value determined for this component is similar, suggesting that the sediment sampled in USU13-2, may be sourced from a 15th century or older accumulation upstream.

• Item Type: Research Reports or Papers (Technical Report)
• Status: Published
• Glasgow Author(s) Enlighten ID: Kinnaird, Dr Timothy and Sanderson, Professor David
• Authors: Kinnaird, T. C., Muñoz-Salinas, E., Sanderson, D. C.W., Castillo Rodriguez, M., and Cruz-Zaragoza, E.
• Subjects: G Geography. Anthropology. Recreation > GB Physical geography
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Publisher: SUERC, University of Glasgow