Continuous XRF Element Characteristics and Significance of Sedimentary Facies Indication of the Quaternary Core from Fuzhou Basin

Abstract

This paper focuses on the study on continuous XRF (X-Ray Fluorescence) scanning elements of a 39 m core from Fuzhou Basin. The XRF scanning result is used to recognize the different sedimentary environment before the discussion of the element variation of different deposit in transitional zone between land and ocean. There are five sedimentary facies in the study area from the late Pleistocene: lacustrine-fluvial-estuary (mud tidal flat)-mixed tidal flat-fluvial. The XRF result from the 5 sedimentary stages shows that the high concentration of Co, Fe, Ti, Si are controlled largely by grain size. The average element intensity of layers with similar grain size indicates that Ca, Ti, Mn, Fe and Co from the marine (tidal flat) deposit is 3~10 times bigger than those from terrestrial (fluvial) deposit, with higher content of Si coinciding with terrestrial deposit. It is indicated that except grain size, the deposit environment is an important factor for element concentration. In this study, Ca, Ti, Mn, Fe and Co are relatively better indicator elements for marine sediments while Si is good and K, Rb and Sr have some indication for terrestrial sediments. The study result shows XRF continuous scanning can help to identify the subtle variation of elements, as to the determination of the sediment facies. Thus, XRF scanning is an important supplement to sediment facies identification. This study also provides an application example of XRF in a typical transitional zone between land and ocean.