Dating of limnic gastropoda shells with electron spin resonance (ESR) tecnique

Electron Spin Resonance (ESR) spectroscopy technique has been employed to date the aragonitic limnic gastropoda shells that were collected from Burdur lake . Firstly, mineral structure and thermal behaviour of shells were determined by using of Fourier Transform Infrared Spectroscopy, X-Ray Diffraction (XRD), Electron Spin Resonance (ESR) and Thermal Gravimetric Analysis (TGA) techniques.To examine and determine thermal stabilities and charactersitics of ESR signals of aragonitic geological fresh-water shells, samples were annealed isochronally and isothermally.The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal. The ESR signal growth curve on additional ?-irradiation has been best fitted by sum of two exponential saturation function. Based on this model, geological dose (GD) value for dating is obtained. To determine the internal and external dose rates, the concentrations of radioactive elements U(two hundred thirty eight), Th (two hundred thirty two) and K (forty) in the shells and surrounding sediments were measured by Inductively Coupled Plasma- Mass Spectrometer (ICP-MS) analysis. The total annual dose rate of the shell samples was found.We have determined the ESR age of the limnic gastropoda shells to be twenty ?three thousand year. The results show that the ESR age falls into the Early Pleistocene epoch of the geological time scale.