Lower Miocene Alluvial Deposits of the Po¾e¹ka Mt. (Pannonian Basin, Northern Croatia): Cycles, Megacycles and Tectonic Implications

• Main Authors: Davor Pavelić, Marijan Kovačić
• Format: Article
• Language: English
• Published: Croatian Geological Survey 2010-11-01
• Series: Geologia Croatica
• Subjects: Braided alluvial fan; Synsedimentary tectonics; Sava fault; Early Miocene; Pannonian Basin; Croatia
• Online Access: http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/279

<div>In the area of the present Po&frac34;e&sup1;ka Mt. braided alluvial fans were</div><div>formed during the Early Miocene above the subsiding Cretaceous-</div><div>Palaeogene basement. Due to autocyclic processes, i.e. lateral migration</div><div>of flows due to vertical aggradation of longitudinal bars, or</div><div>migration of the main trench, small-scale fining-upward cycles were</div><div>formed. The complete succession of the alluvial deposits is composed</div><div>of two fining-upward megacycles, which are the consequence of allocyclic</div><div>influences, i.e. the pulsating character of synsedimentary tectonics.</div><div>Megacycles were developed parallel to backstepping of the</div><div>front of the fault scarp towards the mountain massif, caused by normal</div><div>faulting along the active margin of an extensional basin. This</div><div>kind of depositional style indicates that the Sava fault operated as a</div><div>normal fault at the beginning of its life during the Early Miocene,</div><div>probably the Ottnangian.</div>