Page 220 - Carbonate Platforms Facies, Sequences, and Evolution

of
or
ity
aff.
206
(Fig.
5):
even
Reworked
surface,
gravitational
Cribellopsis
which
Valanginian
is
deposits,
microfaunas
thieuloyi,
are
and
pelagic
gullied,
are
and Paracoskinolina? jourdanensis,
cutting
extremely
limestone
Orbitolinopsis
rich
and
in
characterized
(probable Hugii Zone). It lies above an unconform­
marl.
(large-sized forms), and at the top, by the appearance
by
elongata and Urgonina al pillensis-protuberans
species typical
Hauterivian
the
debelmasi
at the base, the association of Cribello psis
of
the
ation
tuberans
of
Jura
the
(C.
large-sized
A. Arnaud-Vanneau and H. Arnaud
clearly
aff.
Borne
forms
of the early Barremian.
of
indicates
elongata,
bioclastic
that
Urgonina
the
Two observations may be stressed.
Urgonian limestone.
observed
limestone
at
edge was a bypass margin
developed in the northern
basal
Hauterivian (middle to late
is
drowned platform sediment;
wedge (Glandasse bioclastic
to the first appearance of the
domain of the Jura platform.
Barremian: the Jura platform
Fig. 3. Palaeogeographic maps
corresponding to the boundary
the
early Aptian, deposition of the
limestone formation) above the
Dauphinais Basin; (2) lowstand
Dauphinais Basin and the inner
level; (1) submarine fan (Borne
Subalpine chains (Fig. 1) . Early
hemipelagic sediments were well
the early Cretaceous. Tithonian­
near the Isere Fault (Fig. 2); this
Lowermost early Barremian age,
previous Hauterivian hemipelagic
early Berriasian: the southeastern
bioclastic limestone formation) of
Hauterivian): the 'Pierre Jaune de
between the pelagic domain of the
corresponding to four stages in the
emerged during a major drop in sea­
strati­
lowstand wedge) . Late Barremian­
Neuchiitel' bioclastic limestone is a
al pillensis- pro­
the small hatched area corresponds
ramp and slope (within dotted area,
associ�
development of the platform during
edge of the Jura platform is located
of the Pierre Jaune de Neuchatel). (2) The presence
of these foraminifera has been found in the carbonate
graphically located above the topmost levels of the
top
located in the pelagic domain of the
(1) Only one
formations of the northern Subalpine chains and of