SEDIMENTOLOGY OF WARTANIAN OUTWASH NEAR BELCHATOW, CENTRAL POLAND

The braided outwash of Wartanian age near Belchatow, central Poland, w as formed synchronously by two river systems: glacier streams flowing from the northwest and west and periglacial rivers flowing from the so uth and southwest. An extensive alluvial fan was formed which later de veloped into a highly aggrading fan due to a rising water level in the proglacial lake to the north. Braided streams were represented by rel atively low-energy systems with shallow-channel and/or transverse bar deposition. Sporadically, rapid inflows of meltwater caused more energ etic conditions and formation of large scours. The latter were found o nly in the glacier streams and this was confirmed by palaeocurrent mea surements and analyses of quartz roundness.