PINNING POINTS - A METHOD PROVIDING QUANTITATIVE CONSTRAINTS ON RELATIVE SEA-LEVEL HISTORY

Quantitative constraints on the history of relative sea level allow for a better understanding of the controls on depositional sequence development. The constraints are provided by ''pinning point curves'', plots of ancient relative sea-level elevations (pinning points) versus time. Constructing a pinning point curve requires identification of ancient stratigraphic positions of sea level through interpretation of facies and surfaces formed at sea level. Then, their ancient relative elevations are determined through reconstructing aspects of ancient paleotopography. Upper Miocene strata from Las Negras, southeastern Spain preserve paleotopography, contain ancient surfaces of subaerial exposure, and contain facies deposited near sea level. The pinning point curve illustrates a complex relative sea-level history with large- and small-scale relative sea-level fluctuations defined by 31 pinning points.