sheetflood

sheetflood

[′shēt‚fləd]
(hydrology)
A broad expanse of moving, storm-borne water that spreads as a thin, continuous, relatively uniform film over a large area for a short distance and duration. Also known as sheet; sheetwash.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
It consists of alternating beds of clast-supported angular gravels and fine-grained sediments with a dominant tabular geometry (sheetflood deposits).
Where an assemblage can be shown to have been produced by temporally separate events, it can be subdivided into component trace-fossil suites, for example, where a burrow and a boring cross-cut in a sedimentary rock (pre-omission and post-omission suites, Bromley 1990) or where hypichnial and epichnial trackways occur on a sheetflood sandstone bed (predepositional and postdepositional suites, Han and Pickerill 1994).
Hamblin (2001) encountered similar vertebrate trackways, which could be part of a similar ichnocoenosis, on the base of thin sheetflood sandstones in the Hastings Formation on mainland Nova Scotia.
A sheetflood, like a subaqueous turbidite or storm sand, is an episodic and sudden depositional event.
These mudstones cap the same or similar sheetflood deposits described for ichnocoenosis E, and they are stratigraphically adjacent to incipient pedogenic horizons.
In contrast, Buatois and Mangano (1995, 1998) considered the ichnofacies to be from softground transitional environments; marginal of ephemeral lacustrine settings, sheetflood, or fluvial settings.
TF07a) D Floodplain, non- (8 suites: evaporitic, pre- TF01a,TF02b, sheetflood. TF02c, TF02d, TF03h, TF20a, TF20b, and TF33a; ?+4 others, TF03b, TF08a, TF19a, and TF32a) E Syn- to post- (5 suites: sheetflood TF01b, TF16a, TF16b, (or ephemeral channel TF36a, and TF36b) flood deposit).
During more humid periods, large amount of debris and red clays are vehicled as high density bedload by an ephemeral stream network, and they are expended as extensive thinning upward sheetflood sequences at the playa base level.
A variety of lithofacies are present in strata assigned to the Horton Group in southern New Brunswick, including: alluvial fan, sheetflood, fluvio-deltaic, algal swamp, shoreface, carbonate mudflat, shallow lacustrine, evaporitic lake, and offshore lake.
C3 facies is interpreted as overbank deposits produced by the waning flow strength of sandy to muddy sheetfloods through crevasse splays, whereas C4 facies indicates a flood basin origin in a well drained oxygenated environment.
Interpretation: Strata of the C3 facies are interpreted as overbank deposits produced by the waning flow strength of sandy to muddy sheetfloods through crevasse splays, however, sand bodies of lenticular shape represent levee deposits (Smith et al., 1989; Ferrell, 2001) The red color of mudstone, burrows and calcareous nodules indicate partially emergent floodplains (Retallack, 1997; Mack et al., 2003) and substantial aerial exposure (McCarthy et al.,1997).