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Fig. 13.31 Paleotidal modeling of the Lower Cretaceous sea-
ways of Western Europe. Color bar at the bottom gives the mod-
eled tidal range. Several paleogeographic hypotheses, based on
field data of the Greensand Seaway in southern Great Britain
and northern France, are compared: ( a ) seaway connected only
to the North Atlantic; ( b ) seaway connected only to the
Neotethys; ( c ) all three connections open; and ( d ) Neotethys
and North Atlantic connections open, and water depth doubled
in the areas shallower than 200 m. The results show that (i) only
the Neotethys connection was important for the transfer of tidal
energy into the seaway (i.e. there is a significant tidal range
only when the Neotethys connection is open ( b , c and d ), and
(ii) the tidal range increases when sea level is higher (From
Wells et al. 2010 )
References
that original topographic relief may be preserved on
the top of offshore tidal deposits.
Shelf tidal sedimentation can, however, occur at
any time during a relative sea-level cycle, whenever
the sea level interacted with the paleogeography to cre-
ate embayments and straits that accentuated the tidal
currents. Changes in coastal and shelf morphology that
result from a change in relative sea level can cause dra-
matic changes in the strength of the tidal currents on
rapid time scales. Paleotidal modeling has great poten-
tial to assist in understanding the complex temporal
and spacial occurrence of shallow-marine tidal depos-
its in the rock record.
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