Environmental Engineering Reference
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FIGURE 11 Storm-dominated shoreface successions. (A) The Eagle Sandstone shoreface succes-
sion of Montana, USA, consisting of amalgamated tempestites. (B) The Virgelle Member of the
Milk River Formation at Writing-On-Stone Provincial Park, Alberta, showing amalgamated HCS
and SCS. (C) Core-box shots of amalgamated HCS and SCS in the lower- to middle-shoreface suc-
cession of the Cadotte Member of the Peace River Formation, Alberta. Base (B) is to the lower left
and top (T) is to the upper right. Note the general absence of macroscopic burrowing. Scale
bar
15 cm. (D) Cryptically bioturbated sandstone near the base, erosionally overlain by HCS tem-
pestites (arrow) in the Early Cretaceous Cadotte Member, Alberta, Canada. Scale bar
¼
¼
5 cm.
4. TIDAL EFFECTS ON THE SHOREFACE
Tidal effects on the shoreface, and how these are manifesting sedimentologi-
cally and ichnologically, have only recently received attention. What is known
today is almost assuredly going to evolve with time. To date, only a few studies
have been conducted on the sedimentology and ichnology of these systems
(e.g., Ainsworth et al., 2008; Dashtgard et al., 2006, 2009, in press; Frey and
Dashtgard, 2011; Vakarelov et al., in press ); yet, these studies have identified
viable criteria for recognizing tidal shorefaces ( Dashtgard et al., in press ). Tides
can be manifest in one of two ways across the shoreface: either as direct controls
on sediment deposition or, with increasing tidal range, as tidal modulation.
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