| Abstrakt: |
Detrital zircon U-Pb geochronology is a powerful tool for deciphering Earth' s sedimentary archive, answering a large amount of research questions including sediment provenance and palaeogeographic correlations. Although sound reasons exist to conduct qualitative analysis, the advent of large-n acquisition techniques and readily available statistical tools have provoked a shift towards quantitative analysis as the preferred approach during the last two decades. The assumption for a geologically meaningful interpretation of inter-sample comparison through detrital zircon age distributions is that the analyzed samples are a true reflection of the sediment sampled, and this can be used as a proxy for the relative proportion of crystalline rocks in the source region. However, this foundational assumption may be undermined by a number of biases, leading to controversial interpretations and a risk of abuse of the method. In this paper, we demonstrate the principles of the quantitative provenance analysis using detrital zircon U-Pb geochronology and review five major factors that can add bias to the age spectrum and influence the provenance interpretation. The results show the significance to using modern river sand for testing the fidelity of the detrital zircon geochronology because the zircon fertility, hydrological sorting, and sediment mixing can be better constrained than ancient fluvial sequence. Based on the new technologies, including large-n sampling, rim-core dating, and three-dimensional zircon morphology, the quantitative relationship between sedimentary hydrodynamics and age spectra are established, providing further instruction for the provenance study of deep-time sedimentary strata. [ABSTRACT FROM AUTHOR] |
