Ironing out complexities in karst chronology: the Quaternary aeolianite karst phenomenon

This project proposal focuses on the chronology of Quaternary aeolianites (cemented coastal carbonate dunes built of carbonate fragments of marine organisms - bioclasts) and concurrent karst formation. Aeolianite karst holds crucial insights into palaeoenvironment, but there is a significant challenge of its chronological constrains, related to particular aeolianites which do not contain enough of detritus quartz grains for traditional dating methods of their deposition (e.g., OSL), and to the lack of datable material due to dissolution.

The aim of this project proposal is to develop, test and apply a novel 3-phased dating approach and provide a universally applicable dating framework where conventional dating methods could not succeed. We will (1) provide the inception timing of the karst in aeolianites by using U-Th and (U-Th)/He methods on bioclasts; these two methods are well known, but only work well for carbonates in closed system, whilst bioclasts are characterised by open system where water causes complexity related to U-leaching and the presence of detrital Th. Our preliminary research on diagenetic alteration of bioclasts, in combination with alternative correction models for using U-Th on corals of open system behaviour, justifies to push the capability boundaries of these two methods beyond the state of the art. Then we will (2) establish the theoretical meaningful time frame of karstification by mathematical modelling. Lastly, (3) we will establish the so called “climatic-time” when the karstification occurred by using pollen extracted from solution pipe fills.

The project is interdisciplinary, uniting specialists in karst geomorphology, palaeoclimate, sedimentology, geochronology, geochemistry, palynology and physics. The results will have the potential breakthroughs, which are integral to our forthcoming application for an ERC grant, embodying the essence of high-risk, high-gain scientific exploration with the promise of significant global impact.