Fluvial incision and sequence stratigraphy: alluvial responses to relative sea-level fall and their detection in the geological record

Stratigraphic architecture of back-filled incised-valley systems: Pennsylvanian–Permian lower Cutler beds, Utah, USA

“…As incision occurred at a given location in the fluvial channel network, valley widening would have commenced (Leeder and Stewart, 1996). Valley widening would have initially enabled development of minor, gravitydriven slope instabilities; a consequence of oversteepening of the channel walls in response to lateral incision from the fluvial channel element Leeder and Stewart, 1996). These processes would have been exacerbated by low-frequency but relatively high-magnitude rainfall events (typical of fluvial floods in dryland systems) which would have promoted wall-collapse and incised valley growth via the enlargement of wadi systems (cf.…”

“…These processes would have been exacerbated by low-frequency but relatively high-magnitude rainfall events (typical of fluvial floods in dryland systems) which would have promoted wall-collapse and incised valley growth via the enlargement of wadi systems (cf. Leeder and Stewart, 1996;Osterkamp and Friedman, 2000). As the channels incised further, so these processes became more prevalent, with downstream fluvial regions experiencing more lateral widening for two main reasons.…”

Responses of River Deltas to Sea-Level and Supply Forcing: Autostratigraphic View

“…However, if sea level remains stationary, rivers continue to aggrade in response to delta progradation, and consequently never attain grade. Model experiments to examine the dynamics of the downstream and upstream boundaries of alluvial rivers building deltas have shown that alluvial grade is physically possible only under rather specific conditions pertaining solely to sea-level fall (Jordan & Flemings, 1991;Nummedal et al, 1993;Leeder & Stewart, 1996;Muto & Swenson, 2005). Alluvial grade arises in two distinct ways depending on geomorphic conditions and characteristics of sea-level fall, for which alluvial slope S a and basin slope S b are particularly influential (Figs.…”

新しい平衡河川観：モデル実験が描く下流域沖積系の海水準応答

“…Modified from Shanley and McCabe (1994). Muto and Swenson, 2005a;Muto et al, 2007autoretreat Muto and Steel, 1992, 1997Milton and Bertram, 1995;Swenson et al, 2000autobreak Muto, 2001Parker and Muto, 2003;Akamatsu et al, 2005;Parker et al, 2008a, b φ α Muto andSteel, 2002a, 2004;Muto, 2005, 2007 autoincision Muto and Steel, 2002a, 2004Nummedal et al, 1993Schumm, 1993;Leeder and Stewart, 1996 Muto and Swenson 2005a α φ …”