Reconstructing the chemistry of past Earth’s atmosphere and ocean, and their redox states, has gained enormous attention recently. Ocean sediments provide geochemical records through much of Earth’s history. The enrichment of several redox-sensitive trace elements, as well as their isotopic composition in (anoxic) sediments have previously shown to carry important information about the prevailing redox conditions at the time of sediment deposition. Yet, to fully capitalize potential of these emerging redox proxies in reconstructing Earths’ past oxygenation state, a thorough understanding proxies geochemistry in modern environments is mandatory. We aim to further characterise the redox chemistry on proxies which already have some maturity (Mo and U) as well targeting the newly emerging proxies such are V and Re. Combining these proxies will provide an improved framework for interpreting the specific past redox conditions and separate global ocean signatures from localised effects in the sediments. The research within project REDOX will target following subjects:i.) improve the usage of coupled Mo-U abundance and isotopic composition as redox proxy;ii.) development/implementation of specific analytical procedures for determining V redox speciation and Re concentration;iii.) determine the processes controlling Re and V abundance and mobility in sediments and overlying waters spanning oxic, hypoxic and anoxic conditions.The research within REDOX aims to combine particular analytical procedures (chromatographic redox V speciation, Re pre-concentration) with the several others classical analytical techniques (spectrophotometry, MC-ICP-MS and electrochemistry) and the unique study sites along the eastern Adriatic Coast. The research within REDOX is expected to have high impact in the field of environmental and isotope geochemistry, and will significantly contribute to our fundamental understanding of Mo, U, V and Re geochemistry within modern and ancient environments.