Models for relative motion of crustal blocks within the Carpathian region, based on restorations of the outer Carpathian thrust sheets

摘要

Details of the Oligocene‐present‐day motion of the Adriatic block with respect to Europe can be determined by palinspastic restorations of the outer Carpathians thrust sheets. The arcuate nature of the Carpathians poses problems for simple restorations of sections because they create converging restoration paths which require large amounts of strike‐parallel extension (40–50%). Such large amounts of extension are not seen on maps or in the field. A combination of thrust transport directions changing with time between and within thrust sheets and divergent transport directions helps minimise the arc‐parallel extension necessary (18–25%). The Pannonian basin can be treated either as an area dominated by strike‐slip motion (rigid block movements) or as an area of back arc extension. The differences in restoration geometry produced by these two scenarios help to indicate which of the two mechanisms was dominant. The consequences of the rigid block restoration indicate the model is inappropriate because it requires approximately 20° clockwise rotation of the Adriatic block during the late Tertiary. It also indicates at least 300 km strike‐slip motion distributed among the late Tertiary faults of the Dinaride‐Balkanide and Hellenide Mountain belts. The back arc extension model alleviates the the 20° clockwise rotation of the Adriatic block and requires about 200 km distributed strike‐slip motion in Yu