Page 136 - Carbonate Platforms Facies, Sequences, and Evolution

This
In Fig.
ammonite
Domerian
calcareous
Millimetre-scale.
and
particular
pebbles)
example
gastropod
is
from
were reworked
phosphate
one
of
fans and cones were also developed in the
casts.
the
'schistes-carton' early Toarcian (Serpentinus Zone).
Auriolles near Vesseaux. (A) Outcrop. (B) Alternating
Fig. 16. Laminated limestones (arrow) and black shales,
laminae of silty sparites and micrites with quartz grains (a).
remnants of Lower Domerian rocks which are pre­
sediments deposited in medium to low water energy.
Upper
17, angular quartz grains, up to 5mm, are
These
irregularly scattered in a micrite bearing belemnites,
served in a small synsedimentary graben. Submarine
'Couches de Vaumalle' made of coarse
features indicate significant input of coarse material.
rare
and buried in
by
are
can
and
most
cones
nenttc
cutting
be
pebbles
Aubenas.
the
tectonics.
slumps,
grainstones.
escarpments
were
common
fine-grained,
Gentle slopes
common
laterally
in
strongly
bioclasts
'Cancellophycus')
They
slides
Protoglobigerinids
Orcieres
embedded
late Pliensbachian).
Late Triassic and Jurassic platforms, France
the
is
locally
Millimetric
in
are
('Couches
and
controlled escarpments.
somewhat
remains
Slopes and pelagic facies
continuous
bound
developed
bioturbated
lineament.
common
Open
mudstone
marly
at
resedimented
abundant
bioclastic
to
to
strata
and
poorly-sorted
the
throughout
in
of
(from
de Vaumalle',
fissures
slope-breccias.
toe
the
Depending
and
quartz
of
limestones.
packstone
packstones
Facies
on
Fig. 17. Synsedimentary breccia. Gravity redeposited
Zoophycos
Early Domerian. Les Tardieux near La Chapelle-sous-
Bajocian
quartz grains in a biomicritic limestone with belemnites.
the Marly­
Domerian­
fault­
cracks
( =
125
Calcareous Series testify to the role of brittle-style
Bose', early Sinemurian). Small submarine fans and
fault-controlled
hemipelagic to pelagic limestones (e. g., 'Couches du
and
(Fig. 18). More distal environments are indicated by
ranging from early Sinemurian to late Bathonian age
fine-grained
grains
beds
are
in the Oxfordian
middle Oxfordian). During late Bajocian and early
limestones. So-called 'filaments' (Bositra coquinas)
to
They
age and on the depth, the fossil content is varied.
along the slopes bordering the La Voulte escarpment
the
Sponge spicules and calcitized radiolarians are the
and transitional zones are indicated
Bathonian times, Isocrinus breccias were developed
Jurassic.