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398 Facies (2007) 53:389–400
end either with laminated mudstone (MF4) or with peloidal
wackestone/packstone with evaporite pseudomorphs
(MF2). Fenestral fabrics and peloids, interpreted to by
largely derived from in situ mechanical deformation of dis-
jointed cryptalgal laminae, occur at diVerent levels. The
shallowing-upward cycles end with clayey marls and marls
(MF9), reXecting a decrease of accommodation space
related to a fall in relative sea level.
The Wrst Wve cycles are indicative of accumulation in
very shallow restricted lagoonal-peritidal environments
under low water-energy conditions, and probably submitted
to salinity Xuctuations, as attested by the presence of abun-
dant evaporite pseudomorphs.
In the last three cycles, the higher-energy facies (e.g.
MF6 and MF7) become more abundant, indicating a better
connection to the open sea. The ostracods association also
conWrms this trend by the presence of the small ostracod
genus Kerocythere (Fig. 6k, l), associated with the large
genus Lutkevichinella (Fig. 6m, n), which indicates a saline
to brackish environment. We consider that this genus is
allochthonous here.
Two levels of intraformational breccias (MF8) are pres-
ent in this depositional system, directly overlaying the third in a backshoal lagoonal setting. Thin levels of bioclastic
and the fourth genetic units. As recorded in many other
shallow shelf settings (Baum and Vail 1988), lowstand sys-
tem tracts are absent in the Punta Bassano series. Conse-
quently, these breccias, which correspond to transgressive
surfaces, may point to sequence boundaries.
DS2
This depositional system, represented by two cycles, is
28 m thick. The Wrst one starts with 2-m-thick intraforma-
tional breccias (MF8), which indicate a transgressive sys-
tem tract. Afterwards, the depositional conditions remain
constant on the Wrst genetic unit, composed by successive
shallowing-upward facies. This trend includes the microfa-
cies MF1 to MF7 of which, the laminated fenestral wacke-
stone is well developed. This sequence is interpreted as
having formed in the upper intertidal to supratidal environ-
ment of a tidal Xat (e.g. peritidal “island”) on which deposi- limestone interval and then by thin marls. The microfacies
tion/subsidence rate seems to be constant, according to the
regular alternation of the facies. Connections to the open
sea were ensured, as attested by the genus Kerocythere, a
species being characteristic for an open-marine environ-
ment.
The second cycle indicates slightly deepening condi-
tions. It is richer in clayey marls and marls, deposited in a
backshoal lagoon, under very low energy conditions. The
limestone is only represented by few intercalations of iso-
lated beds of mudstone (MF1). Only one bioclastic-rich
level, exclusively composed of crinoid fragments (MF3),
indicates a storm-inXuenced depositional setting.
123
DS3
This depositional system records deepening and more open-
marine inXuences. It reaches a thickness of 26 m, and is made
by four shallowing-upward cycles ending with decimetre-
thick clayey marls and marl intervals. The microfacies of each
cycle reveal higher energy depositional conditions and the
deposition of bioclastic/peloidal wackestone/packstone to
grainstone took place (MF3, MF5 and MF7). Occasionally,
lumachelle layers (MF6) also occur as crinoidal grainstone.
The environmental setting of the sequence refers to a shallow-
marine shoal environment, under medium to high energy.
Two ostracod associations have been found in this interval;
both contain the genera Cytherelloidea and Laevicythere
which characterise a shallow and warm-water setting. The
presence of the species Coronocypris corunula in the ostracod
association from the last cycle clearly indicates more open-
marine inXuences on the shallow-marine environment.
DS4
This sequence, 24 m thick, is subdivided into three distinct
cycles. The thicker, lower cycle is quite similar to the sec-
ond cycle of DS2. It is mostly composed of clayey marls
and marls and reXects quiet and sheltered water conditions
wackestone/packstone (MF3 and MF5) and shelly pack-
stone (MF6) are commonly intercalated, indicating shal-
lower, higher-energy conditions.
The two following shallowing-upward cycles start with
mudstone (MF1), sometimes containing intermittent-
energy storm deposits, and end with decimetre-thick beds
of clayey marls and marls, similarly to the basal cycles of
DS1. Mudstone deposited in the very shallow restricted
lagoonal environment, and storm layers accumulated dur-
ing increasing hydrodynamic activity.
DS5
The last sequence is surely incomplete, because of a dis-
tinct fault. The recognised lower cycle starts with a 1-m-
thick intraformational breccia (MF8) level, followed by a
of the limestone are peloidal wackestone/packstone (MF2),
which gradually passes into a laminated wackestone (MF4)
with fenestral fabrics. This sequence is interpreted as an
upper intertidal to supratidal environment of a tidal Xat,
likewise the Wrst genetic cycle of DS2. The breccias might
indicate the sequence boundary.
The second cycle shows a low-energy facies, from lami-
nated wackestone (MF4) to clayey marls and marls (MF9).
It results from deposition on lagoonal/peritidal protected
areas.