The Prina Complex in eastern Crete and its relationship to possible Miocene strike-slip tectonics

Abstract

The basal Neogene formations in the Ierapetra region, eastern Crete, are strongly influenced by a Late Serravallian tectonic phase which resulted in the breakup of pre-existing palaeogeographic patterns. Important vertical movements caused the southward emplacement of Neogene sediments, together with parts of the underlying pre-Neogene nappe pile. The resulting chaotic association of exotic blocks and sediments, known as the Prina Complex, has the properties of a sedimentary mélange. It can be traced for more than 15 km from north to south. In the north a relatively coherent accumulation of large slide masses overlies deformed Neogene coarse clastics and pre-Neogene rocks. Distally it comprises a poorly stratified sequence of breccias and intermixed finer grained sediments, which locally contains olistostromes and debris-flows and interfingers to the south with submarine fan deposits. The intricate relation of faulting and gravity sliding in a rapidly subsiding basin can be explained by generation in a strike-slip setting. It is suggested that the Ierapetra basin and its offshore extension, the South Cretan trough, were initiated by sinistral movements along a NE-SW oriented fault zone. Implications of this model for the geodynamic evolution of the south Aegean area are discussed.