Back-arc underplating provided crustal accretion affecting topography and sedimentation in the Adria microplate

Abstract

Supported by evidence of deep crustal sources for the observed magnetic anomalies in Central Italy and by outcropping gabbros in the Croatian archipelago, we model the observed gravity and magnetic anomalies in the Central Adriatic Sea and surroundings. We suggest that the major magnetic anomalies in the area are related to a wide underplating and propose that this volume represents the first stage of the back-arc Adria continental breakup in Early Permian times. During the Palaeotethys-Adria collision, underplating has controlled topography and palaeogeographic domains resulting in the observed asymmetrical sedimentary evolution since the Triassic across the Adria microplate. Finally, we propose that the Palaeotethys-Adria boundary in the Early Permian was similar to the current Pacific-Okhotsk plate boundary.