Acquisition of a luminescence dating system and a precision microsampler for the study of environmental changes in the Quaternary period

Abstract

We propose the installation of a system for optically stimulated luminescence (OSL) dating, which employs the single aliquot regeneration (SAR) protocol, and the acquisition of a microsampler (micromill) for the collection of samples at the sub-micron scale, with visual control. The OSL-SAR dating system consists of a germanium detector, an automated luminescence reader with a beta radiation source, an accessory for single-grain OSL measurements with a green laser, and a gas exhaust hood for sample preparation. The microsampler consists of a tungsten carbide drill coupled to an optical microscope with an automated, referenced stage. The main goal of this request is to deeper integrate the research into environmental changes during the Quaternary Period, emphasizing the use of the microsampler for high-precision isotopic analysis of microstratigraphic successions in carbonate materials, as well as focusing on implementation of the single-grain OSL-SAR method, for dating of terrigenous sedimentation events, in Brazil. The correlation of the geochronological results which will be obtained by different methods, for both carbonate and terrigenous materials, will represent an unprecedented advance in research regarding environmental changes during the Quaternary Period in Brazil. The acquisition of the OSL-SAR system will fill a gap in the Brazilian field of geosciences, in terms of analytical methods. Despite the fact that the USP Institute of Geosciences (the petitioner) is the most well-equipped and active geochronology research center in Latin America, neither it nor any other institution in Brazil possesses equipment for dating Quaternary terrigenous sediment, combining precision with the capacity of meeting the needs of a large number of users. We plan to explore various other potential geosciences applications of the requested equipment. The microsampler will be applied in ultraprecise collection of samples from rocks, fossils, and archaeological materials in general, regardless of age or nature. The spectrometer will also be employed for the analysis of provenance and stratigraphic correlation in rocks of any age, with potential use for environmental radiation measurements. (AU)