Rapid spatiotemporal variations in rift structure during development of the Corinth Rift, central Greece

Abstract

The Corinth Rift, central Greece, enables analysis of early rift development as it is young (<5Ma) and highly active and its full history is recorded at high resolution by sedimentary systems. A complete compilation of marine geophysical data, complemented by onshore data, is used to develop a high-resolution chronostratigraphy and detailed fault history for the offshore Corinth Rift, integrating interpretations and reconciling previous discrepancies. Rift migration and localization of deformation have been significant within the rift since inception. Over the last circa 2Myr the rift transitioned from a spatially complex rift to a uniform asymmetric rift, but this transition did not occur synchronously along strike. Isochore maps at circa 100kyr intervals illustrate a change in fault polarity within the short interval circa 620-340ka, characterized by progressive transfer of activity from major south dipping faults to north dipping faults and southward migration of discrete depocenters at ~30m/kyr. Since circa 340ka there has been localization and linkage of the dominant north dipping border fault system along the southern rift margin, demonstrated by lateral growth of discrete depocenters at ~40m/kyr. A single central depocenter formed by circa 130ka, indicating full fault linkage. These results indicate that rift localization is progressive (not instantaneous) and can be synchronous once a rift border fault system is established. This study illustrates that development processes within young rifts occur at 100kyr timescales, including rapid changes in rift symmetry and growth and linkage of major rift faults