Spatio-temporal variation in quartz luminescence sensitivity in the coastal area of China

Abstract

Quartz luminescence signals have been proven to be an effective index for identifying sediment provenance. The provenance of quartz minerals on typical sandy coasts along the east coast of China serves as important evidence for estuarine and coastal aeolian geomorphological processes in coastal zones. However, the temporal and spatial differences in the sensitivity characteristics of quartz grains on the east coast of China remain controversial owing to a lack of systematic analyses of coastal sediments. In this study, we present the thermoluminescence (TL) and optical luminescence (OSL) sensitivity of quartz minerals from core FN1 in the coastal area of Fujian Province, and the relative OSL sensitivity of quartz minerals obtained from Hebei, Fujian, Hainan, and Taiwan provinces. Our results indicate that (1) the OSL sensitivity values of quartz grains in the FN1 core are closely correlated with the mean grain size, electrical conductivity, potential of hydrogen, and end-member, suggesting that the change in luminescence sensitivity may be closely related to climate changes; specifically, cold climatic events during this period can cause significant fluctuations in the sensitivity; further, the percentage contents of fast, medium, and slow components are also different; (2) spatially, there are clear differences between the %FAST value of quartz grains from different sandy coasts; in these coastal dune samples, the %FAST value of the quartz grains during the Last Glacial Maximum (LGM) was significantly different from that of the quartz grains during the interglacial; thus, %FAST can be used to distinguish between glacial and interglacial samples; specifically, the sensitivity of quartz from the glacial dune was higher than that from the interglacial dune, and the sensitivity dispersion of quartz from the glacial as smaller than that from the interglacial coastal dune sand; and (3) the change in the luminescence sensitivity of quartz grains was ultimately controlled by the provenance change. In different geological periods, transgression, regression, and abrupt climate change trigger changes in the supply range of sources, which indirectly affects the sensitivity characteristics of quartz minerals. The spatial difference in quartz sensitivity in the eastern coastal area of China is mainly affected by the characteristics of quartz crystals and types of bedrock, which require further systematic study.