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

Quantitative constraints on the history of relative sea level allow fo r a better understanding of the controls on depositional sequence deve lopment. The constraints are provided by ''pinning point curves'', plo ts of ancient relative sea-level elevations (pinning points) versus ti me. Constructing a pinning point curve requires identification of anci ent stratigraphic positions of sea level through interpretation of fac ies and surfaces formed at sea level. Then, their ancient relative ele vations are determined through reconstructing aspects of ancient paleo topography. Upper Miocene strata from Las Negras, southeastern Spain p reserve paleotopography, contain ancient surfaces of subaerial exposur e, and contain facies deposited near sea level. The pinning point curv e illustrates a complex relative sea-level history with large- and sma ll-scale relative sea-level fluctuations defined by 31 pinning points.