Electron sin resonance (ESR) dating of Quaternary materials

Abstract. ESR dating has become an efficient tool in earth sciences for geochronological studies on different kinds of littoral deposits (coral reefs terraces, beach ridge systems, aeolianites) during the last ten years. Improvements in annual dose rate (D’) estimation and the newly developed approach for equivalent dose (DE) determination (DE -Dmax plot procedure) increase the precision of ESR dating of Holocene and Pleistocene corals as well as marine and terrestrial mollusc shells. This is strongly supported by the comparison of ESR dating results with other numeric dating methods such as radiocarbon and TIMS Uranium series analysis (TIMS 230Th/234U). The latter is the main focus of this paper. The uncertainties associated in ESR dating of Holocene corals coincide with the variability of 14C ages caused by the marine reservoir effect. The dating of Pleistocene corals permits the differentiation between the main marine isotope stages (MIS) 5, 7, 9, 11 and 13 as well as between sub-stages 5e3/2 and 5e1, 5c, and 5a2 and 5a1. The average error range when dating corals is between 5 to 8%. Furthermore, ESR dating of marine and terrestrial mollusc shells has yielded some promising results and permits the differentiation between the interglacial MIS 1, 5, 7 and 9 with an average dating error range of 10 to 15%. ESR dating of quartz is another promising dating technique for Quaternary and even Neogene geological formations. The presence of quartz in volcanic rocks, tephra, fault gouge and sediments (heated or unheated) allows determining the last time of heating, fault movement or sunlight exposure. Although challenged by several experimental issues, ESR dating of quartz is often the only method able to produce numerical ages for older formations. ESR has also been applied to a wide variety of other materials such as foraminifera, speleothems, travertines, calcretes and tooth enamel. The most common and reliable application is the ESR dating of mammal teeth, which becomes in conjunction with laser ablation U-series dating, an important method for determining the age of archaeological sites beyond the time range of the 14C dating method back to about 200 to 300 ka.