Page 243 - Carbonate Platforms Facies, Sequences, and Evolution

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Vanneau,
dissolution,
surface) or,
valleys up to
1980;
dolomite
more rarely,
crystal
> 30m in depth.
Arnaud-Vanneau
Urgonian plat form: transgressive facies
et
dissolution
al.,
filled vertical tubes in limestone (vertical scale bar:
and
High sea-level facies on the Hauterivian ram p and
sub­
corresponds either to the start of karstification (cavi­
by a particular type of transgressive facies (Arnaud­
The horizon of maximum depth is always preceded
1987).
ties penetrating down to a metre or more below the
sequent vadose silt, vadose cement ... The erosion
to the cutting of incised
stromatolite including fine fenestral fabric (horizontal scale bar :
fragments displaying microstalactitic cement (ac). (Scale bar: 1 mm)
flora:
occur
ferent
1 mm).
increase
Whatever
Substantial
with
in
sizes
the
or
brackish
A. Arnaud-Vanneau and H. Arnaud
yellowish colour.
a
clay,
grained sediment,
reworking
location
quartz
deep-subtidal
mixture
or
agglutinated foraminifera),
and
-fresh-water
and
the
marine
of two
iron
mixing
of
organisms
facies
oxide
organisms
fauna
types.
Fig. 24. Normal facies of the top of the inner-platform shallowing-upward sequence. (A) Outcrop view showing calcite­
lO cm). (B) Photomicrograph of bird's eyes in mudstone. (C) Planar
(2) Rounded lithoclasts in a fine­
or even pelagic organ­
or a mixture of bioclasts of dif­
Fig. 23. Storm deposit capping the inner platform shallowing-upward sequence. (A) Outcrop showing a lower bed rich in
large gastropods and an upper bed with coral fragments. (B) Very coarse skeletal fragment grainstone with branching coral
(3)
features (Figs 12 & 25). (1) Appearance or notable
content,
transgressive facies always display four fundamental
stratigraphic level,
( characae)
isms (ammonites). (4) Skeletal grains are commonly
and
resulting in a highly recognizable bluish, reddish or
(small