Four in one: a new crevasse-splay complex in the middle Miocene of central Poland

Abstract

Crevasse splays are typical overbank (extra-channel) deposits, present in all alluvial systems, particularly common on the floodplains of meandering and anastomosing rivers (Makaske, 2001;Miall, 2006;Boggs, 2012;Zieliński, 2014). They form adjacent to the margins of river channels, when the natural levees are locally breached by floodwater. The accumulation of sediments, mainly sand, takes place during the initial stage of a flood. Coarser sediment fractions (medium and fine sands) are deposited closer to the river channel, in the proximal zone of spill-out, while finer fractions (if present) tend to be deposited farther away, in the distal zone of the floodplain (e.g.,