Usa Formation
Members: unnamed (22), Sanashtykgol (1), Unit IX (2), Unit VI (2), Unit VII (1), Unit VIII (2), Unit X (2), Unit XI (3), Unit XII (3), Unit XII/1 (1), Unit XII/2 (1), Unit XIII (2), Unit XIV (3), Unit XIV/1 (1), Unit XV (2), Unit XV/2 (1)
Lithologies: not reported (40), "siliciclastic" (19), mudstone (27), "shale" (25), siltstone (58), sandstone (59), conglomerate (3), "mixed carbonate-siliciclastic" (1), marl (16), wackestone (6), packstone (8), grainstone (1), "limestone" (110), dolomite (1), peat (1)
Paleoenvironments: marine indet. (104), terrestrial indet. (34), carbonate indet. (32), shallow subtidal indet. (2), open shallow subtidal (8), lagoonal/restricted shallow subtidal (1), reef, buildup or bioherm (42), perireef or subreef (7), intrashelf/intraplatform reef (2), slope/ramp reef (1), deep subtidal shelf (1), deep subtidal indet. (1), offshore shelf (1), basinal (carbonate) (1), marginal marine indet. (3), coastal indet. (33), transition zone/lower shoreface (4), offshore (35), submarine fan (3), deep-water indet. (3), fluvial indet. (3), alluvial fan (2), wet floodplain (2), mire/swamp (5), fluvial-lacustrine indet. (1), lacustrine - small (9), lacustrine indet. (2)