Testing of quartz ESR dating for the marine strata on the northwestern coast of Hainan Island

In order to obtain the age range of the marine strata exposed on the northwestern coast of Hainan Island, quartz ESR (electron spin resonance) dating method was adopted to date 7 samples from the upper and bottom outcrops of the strata. In addition, the application of quartz ESR dating method for chronostratigraphy of tropical marine strata was also discussed. Age dating results show that the upper layers are between (33±6.6) ~ (53±10.6) ka and the bottom layers are between (1 835±202) ~ (2567±256) ka, reflecting that the marine strata were accumulated mainly during the Pleistocene. According to the linear fitting results of the ESR signal intensity and irradiation dose, only two samples, one from the uppermost and one from the nethermost, have the best fit, and the ESR signal intensity of the nethermost sample tends to saturation with the irradiation dose. This indicates that 5.1±8.9 ka is the most reliable age for the upper layers, and the bottom of the strata may be beyond the Pleistocene. It is the first application of quartz ESR dating to Pleistocene marine strata of domestic tropical coast in this study. The results not only are the important basis for comprehensive and in-depth quartz ESR dating of the strata exposed in northwestern Hainan Island, but also provide great insights for the ESR dating research of other Pleistocene marine strata.