Table 1. Classification of Late Oligocene Margargaria River strata into depositional units.

	Facies code	Depositional unit	Sedimentary structures	Interpretation
	A	Fine to very fine sand	Cross-laminated	Ephemeral fluvial deposit of low to medium flow speed (i.e. crevasse splay)
	B	Silt and very fine sand	Scour and fill and faintly cross-laminated	Ephemerous small scale channel deposit (i.e. chute)
	C	Silt to fine sand	Massive to faintly laminated	Sediment-gravity flow deposits (i.e. airfall ash)
	D	Clay to fine sand	Cross- to horizontally-laminated	Reduced traction flood deposits (i.e. overbank deposit)
	E	Clay, mud and, very fine sand	Massive	Organic- and clay-rich lag deposits from small streams (i.e., mud drape)
	F	Clay to very fine sand	Massive and bioturbated	Root bed (i.e. paleosol)
	G	organic matter	Poorly-laminated	In-situ deposits of organic matter (i.e. lignite)