Sedimentary layers contain stratigraphic cycles and patterns that precisely reveal the succession of climatic and tectonic conditions that have occurred over millennia, thereby enhancing our ability to understand and predict the evolution of the planet. Researchers at the University of Geneva (UNIGE), Switzerland and international colleagues have been working on an analytical method combining deep-water sedimentary strata observations and measuring the isotopic ratio between heavy and light carbon. They have discovered that the cycles that punctuate these sedimentary successions are not due solely to the erosion of mountains that surround the basin, but are ascribable to sea level changes. This research, published in the journal Geology, paves the way for new uses of isotopic methods in exploration geology.