Study on feldspar thermoluminescence spectra and its luminescence dating implication

Thermoluminescence spectra of feldspar in pegmatite from South China were experimentally investigated using a newly-constructed three-dimensional thermoluminescence spectrometer, under variant experimental conditions: the storage time period between sample irradiation and spectral measurements, the dose rate used for sample irradiation. The experimental results show that (1) the feldspar TL spectra display in a pattern of wavelength bands, centered on eight different distinguishable wavelengths; (2) the thermoluminescence components of feldspar from pegmatite fade away heterogeneously depending on wavelength and thermal stimulated temperature; (3) the two different dose rates used for artificial irradiation result in distinguishable diverse thermoluminescence spectra. All these luminescence spectral characterization features suggest that more complicated ingredients influencing feldspar luminescence dating need to be ruled out than expected. Especially it is necessary to correct the normal luminescence dating results in regard to these influential factors when feldspars extracted from sediments but originating from rocks are used for luminescence dating. On the other hand the experimental results also suggest the feasibility of optimization of feldspar luminescence dating.