Page 251 - Sedimentology and Stratigraphy

238 Shallow Marine Carbonate and Evaporite Environments

"

#

#

!

Fig. 15.15 Generalised facies
distributions on carbonate platforms:
(a) ramps, (b) non-rimmed shelves and
(c) rimmed shelves.

1990; Jones & Desrochers 1992). Wave-dominated shallow water form bioclastic and oolitic carbonate
shorelines may have a beach ridge that confines a sand shoals. Benthic foraminifers are the principal com-
lagoon or a linear strand plain attached to the coastal ponents of some Tertiary carbonate ramp successions.
plain. Ramps with mesotidal regimes will show a mix- The mid-ramp area lies below fair-weather wave
ture of beach barrier, tidal inlet, lagoon and tidal-flat base and the extent of reworking by shallow-marine
deposition. Agitation of carbonate sediment in shallow processes is reduced. Storm processes transport
nearshore water results in a shoreface facies of carbo- bioclastic debris out on to the shelf to form deposits
nate sand bodies. Skeletal debris and ooids formed in the of wackestone and packstone, which may include