Pendant_bar
A pendant bar is a large, streamlined, fluvial bar that is typically composed of gravel which occurs just downstream of a bedrock obstruction within a river channel or floodway that has been scoured by either an outburst flood, megaflood, or jökulhlaup. They are often associated with giant current ripples.[1][2] Malde[3] introduced this to refer to streamlined mounds of gravel deposited by the Bonneville Flood that lie downstream of bedrock projections on the scoured valley floor of the Snake River. They are most common type of bar found within the Channeled Scablands created by the Missoula floods. The obstruction for the initiation of pendant bars in the Channeled Scablands is typically either a knob of basalt or the relict bend of a pre-flood meandering valley.[1][2]
In the Channeled Scablands the larger pendant bars in are up to 2 kilometers (1.2 mi) long and rise 30 m (98 ft) above the floors of the preflood valleys. The bar surfaces lie 30–60 m (98–197 ft) below the high-water surface at the time of their formation.[1][4] During regular annual floods in Central Texas and elsewhere, much smaller, analogous, mid-channel bars form downstream from river channel obstructions, e.g. large boulders of rockfall, or in the lee of barriers of stable trees and logjams.[5]