Age estimation of marine fossils from Phetchabun provice using X-ray analysis

The aim of this research is to apply the material characterization such as the crystal structure and chemical composition for fossil age estimation. The marine fossil consisted of three samples were collected from Nong Phai district, Phetchabun province. All marine fossils were prepared and characterized crystal structure by X-ray diffractometer. The chemical composition of all marine fossils was analyzed by X-ray fluorescence spectrometer. The chemical composition result was used to calculate the strontium and calcium ratio for age estimation of marine fossil. The results showed the marine fossil-1 and marine fossil-2 had like shell embedded in the rock while the marine fossil-3 had like the coral fossil. The main crystal structure of marine fossil-1 and marine fossil-2 were calcite phase, but the marine fossil-3 was quartz phase. The main crystal phase of all marine fossils were confirmed with the chemical composition. The Sr and Ca ratio of marine fossil-1, marine fossil-2 and marine fossil-3 were 1.330, 1.711 and 0.386, respectively relating with the geological time of Permian period. From this experiment indicated that the crystal structure and chemical composition can be used to estimate the age of fossil.