ROBUST MILLENNIAL- AND CENTENNIAL-SCALE INTERPRETATIONS OF LATE PLEISTOCENE SEA-LEVEL CHANGE FROM FOSSIL CORAL REEFS: AN INTERDISCIPLINARY CHALLENGE (Invited Presentation)

Uranium-series dating of fossil corals provides valuable temporal constraints of late Pleistocene sea-level change. In the three and a half decades since the advent of modern mass spectrometric dating, U-series analytical capabilities have advanced to the point where fossil corals can routinely be dated at centennial-to-decadal level precision. Similarly, the research questions addressed by fossil coral reconstructions have also evolved. Whereas earlier studies provided valuable insight into the relationship between glacial-interglacial sea-level change and Milankovich forcing, recent research directions have focused on shorter timescales including investigating suborbital processes that could lead to rapid sea-level change on human timescales. Although the analytical precision of U-series fossil coral ages can resolve millennial- and centennial-scale changes in sea-level, consensus on the rate(s), timing and magnitude of such changes, as well as their climatic forcing mechanisms is often debated. This is because the primary challenge for fossil coral sea-level reconstructions is age interpretation rather than instrumental accuracy or precision. In addition to age and elevation measurements, robust interpretations from fossil coral sea-level indicators require consideration of a myriad of factors, including diagenesis and taphonomy, sedimentological and facies interpretations, reef paleoecology, and geophysical considerations such as glacial isostatic adjustment and dynamic topography. Here, we share some examples from the Last Interglacial period to highlight insights gained from a global compilation of fossil coral sea-level indicators and demonstrate that, fundamentally, fossil coral U-series age interpretations are inseparable from the geologic context. This interdisciplinary perspective is essential to produce robust paleo-sea-level reconstructions.