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ORIGINAL ARTICLE
The Coniacian–Campanian Latium–Abruzzi carbonate platform,an example of a facies mosaic
Marco Brandano • Marco Loche
Received: 7 August 2013 / Accepted: 13 December 2013 / Published online: 4 January 2014
� Springer-Verlag Berlin Heidelberg 2014
Abstract This paper presents the results of a high-reso-
lution analysis of Upper Cretaceous shallow-water lime-
stones in the northeast sector of the Lepini Mountains
(Central Apennines, Italy) that belong to the Latium–Ab-
ruzzi platform domain. The studied succession is entirely
referred to as the ‘‘Accordiella conica & Rotorbinella
scarsellai Biozone’’. The analyzed Coniacian–Campanian
succession is primarily characterized by three lithofacies
associations (LF-A, LF-B, LF-C) deposited on an open
shelf. The intertidal and shallow-subtidal environments are
characterized by mudstone to wackestone and laminated
bindstone (LF-C), whereas in the low to moderate energy
environments of the inner shelf there developed rudist
biostrome (rudist pillarstone) and rudist rudstone to float-
stone (LF-A). A lithofacies association dominated by
cross-bedded grainstone (LF-B) represents the reworking
of bioclastic grains (rudist fragments) derived from the
areas of the shelf colonized by rudist biostrome; lime-sand
shoals related to storm channels passed into submarine
dunes in an open-shelf setting. Correlation of the five
investigated stratigraphic sections shows how the recog-
nized LF are laterally associated to form a facies mosaic
over a few hundred meters. The stratigraphic architecture
shows five intervals (I–V) each of which is dominated by
one or two LF. Interval I is intensely dolomitized. The
following intervals (II and III) record a gradual increase in
hydrodynamic energy as evidenced by the presence of
rudist biostromes passing upward into cross-bedded
grainstone. An increase in mud-supported textures in the
interval IV suggests more restricted conditions, which were
terminated by a period of emergence. More open-marine
conditions in the final interval (V) are shown by the
dominance of LF-A and LF-B.
Keywords Coniacian–Campanian � Apennines �Open shelf � Rudist � Facies mosaic
Introduction
Carbonate platforms are characterized by many carbonate
factories related to different environmental factors existing
across the platform (Wright and Burgess 2005). The con-
cept of facies mosaic has been used to understand the
complexity of a platform’s sediment composition (Wright
and Burgess 2005; Strasser and Vedrine 2009; Pomar and
Hallock 2008). As demonstrated by Strasser and Vedrine
(2009), many carbonate environments are unstable, e.g.,
mud-banks and sand shoals shift laterally due to tidal and
long-shore currents and, as a consequence, these currents
also modify adjacent environments. Storm waves and
storm-induced currents lead to abrupt changes in facies by
redistributing sediment. Considering the complexity of
modern carbonate platforms, it must be expected that the
sedimentary record of such depositional systems is equally
complex.
This paper describes facies mosaics from a rudist-
dominated carbonate platform from the Coniacian–Camp-
anian interval that widely crops out in the Central and
Southern Apennines (Civitelli and Mariotti 1975; Accordi
and Carbone 1988; Carannante et al. 1993, 2000; Stossel
and Bernoulli 2000; Simone et al. 2003; Ruberti et al.
M. Brandano (&) � M. Loche
Dipartimento di Scienze della Terra, La Sapienza Universita di
Roma, P. Aldo Moro 5, 00185 Rome, Italy
e-mail: [email protected]
M. Brandano
Istituto di Geologia Ambientale e Geoingegneria (IGAG) CNR,
Via Salaria km 29, 300, 00016 Monterotondo, Rome, Italy
123
Facies (2014) 60:489–500
DOI 10.1007/s10347-013-0393-x
2006). The Coniacian–Campanian shallow-water carbon-
ates of the Apennines were deposited on open shelves
where the skeletal assemblages of the main carbonate
factory are made up of rudists and foraminifera that pro-
duced loose, bioclastic debris reworked by storm- and
wind-induced currents and waves (Simone et al. 2003;
Ruberti et al. 2006).
Many studies of Cretaceous platforms concentrate on
the description of biofacies and lithofacies, production of
depositional models and on the identification of high-res-
olution depositional cycles (e.g., parasequences, simple
sequences) (Borgomano 2000; Johnson et al. 2002; Simone
et al. 2003; Pomar et al. 2005; Ruberti et al. 2006). Less
attention has been given to the scale and extent of facies
associations characterizing these Cretaceous platforms.
The Latium–Abruzzi platform is a large ([100 km wide)
platform. The extent of the investigated outcrops permits
observations of lateral changes in facies over a few hun-
dred meters. Wright and Burgess (2005) pointed that many
descriptions and interpretations of ancient outcrop strata
assume a layer cake architecture instead of considering
facies mosaics. Strasser and Vedrine (2009) underlined the
discrepancy of the resolution of facies detail and interpre-
tations between ancient and modern depositional environ-
ment. The aim of this paper is to report the results of a
detailed analysis in order to propose a depositional model
for the investigated deposits, to identify the building blocks
of the succession, and to analyze their vertical evolution
and response to sea-level changes. In this paper, the focus
is on the western sector of the Latium–Abruzzi platform,
one of the central Apennine platforms, where complex,
gradual lateral and vertical facies changes are recorded,
which can be interpreted using the facies mosaic concept.
This study provides an example of the application of the
concept of facies mosaic on a rudist-dominated carbonate
platform where this concept appears more relevant to
explain the stacking of individual lithofacies and platform
facies distribution.
Geological setting
The study area is located in the Lepini Mountains that form
the western side of the central Apennines (Fig. 1). This
structure represents the accretionary wedge developed
along the subduction hinge of the Adria continental plate
and the Ionian oceanic plate (Paleo-Ionian oceanic corri-
dor) (Gueguen et al. 1998; Carminati et al. 2007, 2010).
Two main platform successions crop out in the central
Apennines (Bernoulli 2001; Parotto and Praturlon 2004 and
references therein): the Latium–Abruzzi Platform in the
west and the Apulia Platform in the east. They are sepa-
rated by a narrow basinal corridor in the Monte Genzana
area. The Latium–Abruzzi Platform consists of a thick,
Fig. 1 a Simplified geological map of central Italy showing the location of the Apennines platforms (modified from Eberli et al. 1993).
b Location of investigated stratigraphic sections in the Lepini Mountains
490 Facies (2014) 60:489–500
123
discontinuous succession of about 5,000 m of limestone
and subordinate dolomite of Late Triassic to Late Miocene
age. During the Early Cretaceous, the Latium–Abruzzi
Platform was characterized by spreading of peritidal facies
and frequent emergence episodes testified by charophyte-
rich levels and paleokarst features, culminating with the
deposition of bauxites during the late Albian-Cenomanian
(Parotto and Praturlon 2004). During the Late Cretaceous,
a large open shelf developed during the Coniacian–
Campanian interval with rudist facies occurring mainly in
the northern sector of the platform (M. Carseolani and M.
Lepini) (Mariotti 1982; Chiocchini et al. 1994; Chiocchini
and Mancinelli 2001). The uppermost Cretaceous interval
(late Campanian and Maastrichtian) is recorded only in the
marginal area and in the slope sector, where it is repre-
sented by Orbitoides pack-grainstone (Chiocchini and
Mancinelli 2001). A Late Cretaceous-Paleogene hiatus is
physically expressed by a paraconformity recognizable
within the carbonate platform domains. Above this strati-
graphic discontinuity, Lower and/or Middle Miocene car-
bonates directly overlie Cretaceous limestone (Civitelli and
Brandano 2005).
Biostratigraphy of Coniacian–Campanian interval
The studied carbonate platform succession is assigned to
the ‘‘Accordiella conica & Rotorbinella scarsellai Bioz-
one’’ of Chiocchini and Mancinelli (1978) and Chiocchini
et al. (1994, 2008) (Fig. 2). This biozone covers a time-
interval ranging between the Early Coniacian and Early
Campanian, according to the stratigraphic distribution of
the same taxa recognized in the southern Campanian
Cretaceous limestones of Apennine platforms (cf. Sgrosso
1968; Carannante et al. 2000; Simone et al. 2003; Cestari
and Pons 2004), including, in its middle portion, a bio-
horizon bearing Keramosphaerina tergestina, ascribed by
Molinari-Paganelli and Tilia-Zuccari (1987) to an interval
not older than Coniacian–Campanian. Furthermore, the
recognized faunal associations compare well with those
described by Checconi et al. (2008) in Puglia (southern
Italy). In view of the broad time interval of the biozone, it
was crucial to assign a more precise age to the studied
deposits. The first occurrence of Keramosphaerina ter-
gestina takes place in the middle part of investigated
sections C and E (Fig. 3), associated with Murgella lata
and Scandonea samnitica, suggesting a Coniacian–
Campanian age (Tesovic et al. 2001) for this part of the
section.
Materials and methods
Good outcrop exposure on the southwestern slope of Monte
delle Castagne (Lepini Mountains) enabled the measure-
ment of five stratigraphic sections (A–E), which were
correlated in order to interpret vertical and lateral facies
associations roughly oriented along the depositional dip
direction of the Upper Cretaceous Latium–Abruzzi plat-
form (Figs. 1, 3). Sedimentary structures were distin-
guished with line-drawings on photographs to enable the
characterization of the geometries of depositional bodies
and interpretation of the different hydrodynamic regimes in
each depositional environment.
These observations were complemented by petrographic
examination of 60 thin-sections to characterize rock tex-
tures and identify skeletal components. The textural clas-
sifications of Dunham (1962), modified by Embry and
Klovan (1971) and Insalaco (1998) were used.
Results
Lithofacies associations
Lithofacies definition was based on rock textures, skeletal
components, bedding and geometric relationships and three
were recognized: LF-A, -B, and -C.
LF-A: rudist pillarstone and rudist rudstone to floatstone
laterally passing into wackestone to packstone
Rudist pillarstone forms biostromes up to 0.5 m thick and
several meter wide (Figs. 4, 5), which do not show evi-
dence of morphological relief. The matrix comprises wa-
ckestone to fine-packstone with small benthic foraminifera.
Most of the rudists are of elevator morphotype (Skelton
1978; Skelton and Gili 1991; Gili et al. 1995). Locally,
during their early growth, rudist shells were oriented par-
allel to bedding and an upward curvature of shells was
observed in their final growth position. Rudists also occur
throughout the sediment. Rudist pillarstone is characterized
by species belonging to the Durania, Radiolites, Sauva-
gesia, Gorjanovicia, and Biradiolites genera, which usually
Fig. 2 Biostratigraphic scheme and chronostratigraphic references
for the investigated interval of the Apennine carbonate platform
succession (after Chiocchini et al. 2008)
Facies (2014) 60:489–500 491
123
form oligo- or monospecific assemblages. Rudist floatstone
to rudstone is characterized by toppled and/or iso-oriented
rudist shells lacking the upper valve. The matrix is com-
posed of fine packstone to wackestone with small benthic
foraminifera (Fig. 6a). The coarse sandy matrix consists of
skeletal fragments, with a large proportion derived from
bioerosion and mechanical breakdown of rudist shells. LF-
A is organized into 0.2–1-m-thick beds, which locally
extend laterally for tens of meters. The density of rudist
assemblages varies laterally, showing transitions from ru-
dist rudstone to rudist floatstone. The lateral evolution of
this lithofacies association is related to the presence of
rudist biostromes (rudist pillarstone). There is a decrease in
shell debris abundance with increasing distance from the
bioherm. Rudist floatstone passes laterally into wacke-
stone/packstone lithofacies showing planar to low-angle
cross-lamination (HCS) and millimetric-thick layers of
rudist bioclasts (Fig. 6b).
Fig. 3 Architectural reconstruction of the investigated succession
obtained by the correlation of five measured stratigraphic sections.
The correlation panel illustrates the lateral and vertical lithofacies
associations. Cycles 10 and 12 show the lateral relationships between
lithofacies associations produced by a facies mosaic deposited in
environments ranging from intertidal (LF-C) to subtidal (LF-A and
LF-B)
492 Facies (2014) 60:489–500
123
The microfauna of LF-A is characterized by the abun-
dance of small and thin subspherical-shaped Nubeculariidae
and porcellaneous foraminifera (predominantly Miliolidae).
Subordinate microfauna include large-sized discoidal ben-
thic foraminifera (Dicyclina sp., Dicyclina schlumbergeri),
simple porcellaneous forms, Moncharmontia apenninica
and other agglutinated foraminifera, green-algal fragments,
thin-shelled ostracods, textulariids, and rare thaumatopo-
rellaceans (Fig. 4c).
Interpretation: LF-A formed in low-to-moderate hydro-
dynamic energy conditions in an inner-shelf setting (Simone
et al. 2003). This facies association suggests deposition on a
Fig. 4 a Keramosphaerina tergestina; b Scandonea sannitica; c Dicyclina sp. and Thamatoporella parvovesiculifera; d Accordiella conica
Facies (2014) 60:489–500 493
123
rudist-inhabited sandy seafloor, where the bulk of carbonate
sediment was derived from the fragmentation of rudist shells
(Carannante et al. 2000, 2003; Simone et al. 2003; Ruberti
et al. 2006). During storm events, biostromes were partially
reworked and rapidly buried by sediments such that some
rudist shells remained well preserved as they became pro-
tected from wave action (Carannante et al. 1997; Simone
et al. 2003). Rudist floatstone and rudstone appear to be
condensed layers of rudist shells created by the winnowing
of matrix sediment by bottom currents that resulted in the
toppling and dense stacking of shells (cf. Kidwell and Hol-
land 1991; Skelton et al. 1995).
The textural characteristics of LF-A suggest moderate
transport and reworking in a moderate-energy environ-
ment. Much of this reworking is attributed to storm events
that produced HCS from combined flows involving the
action of both waves and currents.
The microfauna characterizing this lithofacies associa-
tion is typical of well-lit depositional environments, open-
water circulation, and normal salinity with moderate
hydrodynamic energy as indicated by the test thickness of
foraminifer specimens (e.g., Hallock 1979, 1983).
LF-B: cross-bedded grainstone to packstone with scattered
rudist pillarstone and floatstone
Cross-bedded grainstone to packstone beds occur in
0.2–0.5-m-thick, first-order sets. The sets form cosets
(second order) up to 3 m thick that can be laterally traced
for tens of meters. Lamination in first-order sets is char-
acterized by concordant and tangential bedding-plane
geometries and dips between 5� and 10�, generally towards
the north. The grainstone is mostly composed of rudist and
echinoid fragments and porcellaneous foraminifera and
rotaliids (Rotorbinella scarsellai, Rotorbinella campaniola,
Rotorbinella sp.). Intergranular pore-space is filled with
sparry calcite cement, which is often replaced by dolomite.
Components of the packstone include agglutinanted, soritid
foraminifers (Scandonea samnitica, Murgella lata), large
lituolids, porcellaneous foraminifers (predominantly com-
plex big and thick-shelled Miliolidae) and subspherical-to-
cylindrical thaumatoporellacean algae.
Cross-bedded grainstone may be laterally associated
with small rudist pillarstone forming beds up to 0.2 m
thick. Rudists show mainly clinger and elevator
Fig. 5 Rudist pillarstone and rudstone to floatstone of LF-A. Note the
rudist floatstone to rudstone lithofacies in the lower bed, where rudists
are considered a relic of an earlier phase of colonization which was
possibly destroyed by a high-energy event. In the upper bed, rudist
pillarstone does not show evidence of morphological relief, with
rudists mainly of elevator morphotype
494 Facies (2014) 60:489–500
123
morphotypes, organized in small bouquets. Rudist pillar-
stone may pass laterally into rudist floatstone (Fig. 6a).
These layers are usually sheet-like and laterally discon-
tinuous. Wavy- to cross-lamination, passing into hum-
mocky cross-stratification is common and is associated
with normal grading (Fig. 6a–c).
Interpretation: Cross-bedded grainstone is interpreted
as the result of the reworking of the bioclastic sands
previously colonized by rudist biostromes. The mobili-
zation of sediment took place in response to storm or
wave currents that promoted the development of migrat-
ing sand-dunes (Simone et al. 2003). These bioclastic
sediments may have become the substrate for new rudist
biostromes (rudist pillarstone) that contributed to the
formation of bioclastic beds (rudist floatstone to
rudstone).
The microfauna characterizing LF-B suggest open-water
circulation and medium–high hydrodynamic energy, as
evidenced by thicker shells and ovoidal-to-subspherical
shapes of rotaliids. The abundance of rudist fragments
(mostly radiolitid shell fragments) indicates the presence of
a rudist-inhabited sandy seafloor, where large rotaliids
were prolific producers of the sand-grade sediment (Car-
annante et al. 2000).
Fig. 6 a Discontinuous and sheet-like rudist floatstone of LF-B.
b Wavy- to cross-lamination evolving into hummocky cross-stratifi-
cation characteristic of LF-B. c LF-B vertical association showing
rudist floatstone passing upward into bioclastic packstone followed by
cross-bedded grainstone at the top
Facies (2014) 60:489–500 495
123
LF-C: mudstone to wackestone and laminated bindstone
LFC lithofacies predominantly is made up of peloids and
micrite matrix with scattered dolomite rhombohedra
(Fig. 7e). The most common skeletal grains are Baci-
nella, small-sized miliolids and thin-shelled ostracods.
Rare benthic agglutinated foraminifers (Cuneolina sp.,
textulariids) and recrystallized gastropod shells also
occur.
Mudstone is characterized by laminoid fenestrae
(Fig. 7f). The fenestrae are filled with cement or sediment.
Skeletal components are mainly thin-shelled ostracods,
with green algal fragments, Aeolisaccus sp., and charo-
phyte oogonia present locally. Rare peloids and small
benthic foraminifera (miliolids) occur together with some
recrystallized gastropod shells. Ostracods are mainly rep-
resented by well-preserved disarticulated valves and only a
few specimens show articulated valves.
The deposits show sedimentary structures resulting from
desiccation processes (birdseyes), and microbial layers,
characterized by clotted textures, bearing charophyte
oogonia.
The laminated bindstone is characterized by alternating
peloidal layers, thin clotted micrite layers, and intercalated
laminoid fenestrae. The peloidal layers consist of micritic
grains that are grain- or mud-supported. Mud-supported
textures are associated with micrite layers, which locally
show microbial structures. Other, minor components are
recrystallized gastropod shells, rare ostracod shells,
smaller benthic foraminifera (miliolids) and rare green
algal fragments and Aeolisaccus sp. The intergranular pore
spaces are filled with calcite spar. The fenestrae are
irregular in shape and size with smaller fenestrae corre-
sponding to birdseyes whereas larger structures have
stromatactoid shapes. These structures are also filled with
calcite spar.
Interpretation: LF-C indicates low-energy depositional
environments between upper intertidal and restricted
lagoon environments (Wilson 1975; Hardie and Ginsburg
1977; Simone et al. 2003; Flugel 2004). The low diversity
and low abundance of fossils and the presence of charo-
phyte oogonia indicate variable salinity. Salinity variation
from fresh to brackish water may result from periods of
heavy rainfall (Joachimski 1994) or alternation between
subaerial exposure and flooding in the upper intertidal zone
(Colombie and Strasser 2005). Cyanobacterial laminites
are interpreted as the products of shallow subtidal silty
flats, locally covered by cryptomicrobial (Aeolisaccus)
mats, and very shallow lagoons. The moderate diversity of
the faunal assemblage in wackestone and mudstone indi-
cates a lateral association with restricted to semi-restricted
lagoonal environments.
Discussion
The Coniacian–Campanian rudist-dominated limestones of
the Southern Apennines were interpreted as being depos-
ited in an open-shelf setting by Carannante et al. (1995,
1999, 2000), Simone et al. (2003) and Ruberti et al. (2006).
They demonstrated that these deposits cannot be inter-
preted through the classical model of a tropical rimmed-
shelf (Ruberti et al. 2006 and reference therein). The Co-
niacian–Campanian Apennine Platforms were dominated
by bioclastic sedimentation comprised mainly of molluscs
and foraminifers, with subordinate green algae, red algae,
ostracods and echinoids. Storm- and wave-induced currents
controlled sediment distribution on the seafloor. Rudists
thrived in most platform environments and provided the
bulk of the skeletal components by means of bioerosion.
Simone et al. (2003) distinguished two main rudist-rich
environments characterized by different hydrodynamic
conditions in an open-shelf setting: (1) a high-energy
environment dominated by lens-shaped, rudist-rich sedi-
ment bodies, with very low to absent relief where rudists
and rudist fragments were washed by wave- and storm-
induced currents that caused the toppling of shells and their
rare in situ growth preservation; (2) a low-energy envi-
ronment developed in sheltered sectors of the platform,
dominated by mud- to silt-rich sediments, where rudists
were preserved in growth position with much bioerosion-
derived sediment. A transitional setting between storm-
dominated and relative low-energy environments was also
documented (Simone et al. 2003).
Ruberti et al. (2006) proposed a depositional model for
these platforms consistent with an open shelf with low tidal
range upon which gradual lateral facies transitions occur
and facies belts are very wide and lack a distinct shoal
complex. Wave energy was minimal because of dampening
by friction along the broad (hundreds of kilometers wide),
shallow-water (above storm-wave base) environment. In
this hydrodynamic setting, in the inner sector of the plat-
form, storm- and tidal- related scours and channels devel-
oped and successively were filled by fine sediment
dominated by foraminifera which represents the prevailing
lithofacies.
The recognized facies associations of Lepini Mountains
compare favorably with the model of Ruberti et al. (2006).
LF-C represents intertidal facies deposited in a low-energy
sector of the shelf. The laminated bindstones are inter-
preted as the deposits of intertidal to shallow subtidal silty
flats locally covered by microbial mats. This environment
was associated with very shallow lagoons in which scat-
tered, small rudist colonies occurred (cf. Simone et al.
2003). LF-A represents sedimentation associated with the
growth of rudist biostromes in low to moderate energy, silt-
496 Facies (2014) 60:489–500
123
Fig. 7 a Wackestone with small benthic foraminifera constituting the
matrix of a rudist floatstone in LF-A. b Rudist fragments derived from
bioerosion and mechanical breakdown forming the main components
of a packstone in LF-A. c Components of the cross-bedded
grainstones of LF-B including rudist fragments, foraminifera (rotal-
iids and miliolids) and thaumatoporellaceans. d Thick-shelled
porcellaneous foraminifera (Scandonea, miliolids) and agglutinated
foraminifera (Cuneolina) are common components of packstone in
LF-B. e Mudstone and wackestone of LF-C showing peloids, small-
sized miliolids, and thin-shelled ostracods. f Laminated bindstone of
LF-C showing irregular shape and size of fenestrae. Scale bar 500 lm
Facies (2014) 60:489–500 497
123
dominated environments where rudists were preserved in
growth position. The rudists grew on a subtidal, bioclastic
sandy seafloor where the bulk of the sediment was pro-
duced from fragmentation of rudist shells. The bioclastic
packstone to wackestone, made up essentially of forami-
niferal tests, periodically resulted from storm and wave
processes.
The cross-bedded grainstone of LF-B is interpreted as
the product of the sedimentation of the bioclastic fraction
derived from the reworking of rudist biostromes. LF-B
represents the migration of bars and sand-waves forming in
storm- and tidal-related scours and channels successively
passing into submarine dunes in an open-shelf setting. On
the open shelf, these bioclastic sand dunes formed the
substrate for rudist biostromes.
The correlation panel in Fig. 3 shows the lateral and
vertical relationships between the different facies associa-
tions. The correlation panel is roughly oriented in a dip
direction. It shows a very small part of the large Latium–
Abruzzi Platform that, like the other Apennine carbonate
platforms, is considered an epeiric platform (Ruberti et al.
2006). Consequently, it was not possible to determine the
size and orientation of facies belts along depositional dip
but the detail of facies associations and the resulting facies
mosaic could be evaluated over a few hundred meters.
The recognized facies are arranged into shallowing-
upward cycles with silt- and mud-rich facies at the top of
each cycle. However, the cycles were only evident after the
correlation of stratigraphic sections. Analysis of only one
section could result in a misinterpretation because the lat-
eral passage from mud-dominated to grain-supported
lithofacies (e.g., cycles 3, 6, and 12 in Fig. 3) could be
missed. As a consequence, the same cycle could appear to
have a different expression in two sections that are within
250 m of each other. This is obvious in modern carbonate
environments where mud banks, sand waves, and tidal
channels shift laterally in response to tidal, wave- and
storm-induced currents. These currents also modify the
adjacent environments and control the redistribution of
sediments and the resulting facies (Strasser and Vedrine
2009). This means that some of the vertical facies transi-
tions observed in the investigated section (see correlation
panel Fig. 3) may be ascribed to autocyclic processes. The
correlation panel also demonstrates the lateral relationships
between the three lithofacies associations (e.g., cycles 10
and 12), that were deposited in three different depositional
environments ranging from the intertidal (LF-C) to the
subtidal (LF-A, LF-B). The passage from intertidal to fully
subtidal takes place within a distance of 250 m and not
over many kilometers as presented in the classical model.
This may be considered the expression of a facies mosaic.
As evidenced by Wright and Burgess (2005), there is a
continuum of carbonate factories and facies related to
many environmental and depositional processes. In this
example, the rudist carbonate factory of LF-A is associated
with cross-bedded grainstone of LF-B, representing
migrating sand-dunes.
The record of sea-level changes is less ambiguous on a
scale of decameter-thick intervals. In the investigated suc-
cession, five major intervals are recognized (I–V) each of
them dominated by one or two facies associations. Interval I
is 35 m thick and consists of intensely dolomitized lime-
stone and it was not possible to recognize the lithofacies
associations except for a limited interval of a few meters of
LF-B. Interval II is 8 m thick and is dominated by rudist-
rich facies (LF-A). It passes upwards into the 10-m-thick
interval III, where the LF-B represents the main facies
association but LF-A is still common. Interval III records an
increase in hydrodynamic energy, suggesting more open
conditions. Successively, the succession records increas-
ingly mud-supported textures in interval IV, documented by
the spread of LF-C, which indicates more restricted con-
ditions up to the emergence in the upper part of this interval.
A new episode of open-marine conditions is marked by the
occurrence of LF-A and LF-B in interval V.
Conclusions
The Coniacian–Campanian platform of the Lepini Moun-
tains, Apennines, Italy, is characterized by three lithofacies
associations (LFA-C) deposited in an open-shelf setting
where there were gradual lateral facies transitions. LF-C
represents sedimentation on intertidal to shallow subtidal
silty flats locally covered by microbial mats. The growth of
rudist biostromes, represented by LF-A, took place in a
low-to-moderate energy environment. The grain-supported
LF-B resulted from sedimentation of the bioclastic fraction
derived from reworking of rudist biostromes in an open-
shelf setting. These bioclastic sands formed bars and sand-
waves related to storm channels and submarine dunes on
the open shelf. The correlation panel of the five investi-
gated sections shows that the recognized LF laterally pass
into one another over a few hundred meters, forming a
facies mosaic.
The recognized facies are arranged into shallowing-
upward cycles characterized by silt- and mud-rich facies at
the top of each cycle. However, these cycles were only
recognized through the correlation of stratigraphic sections
and were less evident by analyzing the single stratigraphic
sections.
In the Lepini Mountains succession, five main intervals
were recognized, each of them dominated by one or two
facies associations. With the exception of the basal part of
interval I, which is composed of intensely dolomitized
intervals, the first record of a gradual increase in
498 Facies (2014) 60:489–500
123
hydrodynamic conditions suggesting more open conditions
occurs in intervals II and III, followed by an increase in
mud-supported textures in interval IV, suggesting more
restricted conditions that culminated in emergence. A
renewal of open conditions is marked by the dominance of
LF-A and LF-B in interval V.
This outcrop investigation evidences how the applica-
tion of facies mosaic concept supports the role of the
autocyclic factors in the generation of shallowing-upward
cycles and attenuating the allocyclic forcing in a rudist
dominated platform.
Acknowledgments Funding for this research was provided by
PRIN Project 2010–2011 (leader E. Carminati). Reviewers Esmeralda
Caus and Johannes Pignatti and the editor Maurice Tucker are
thanked for critical comments that greatly improved this work. Spe-
cial thanks are due to James Hodson (RPS ENERGY) for English
review and for constructive sedimentological comments. Many thanks
to Simona Caruso to optimize. Goffredo Mariotti and Johannes Pig-
natti are thanked for indicating the investigated outcrops. We extend
our thanks to Angelo Coletti, Lorenzo Consorti, Laura Tomassetti,
and Giacomo Brandano for their help during fieldwork.
References
Accordi G, Carbone F (1988) Sequenze carbonatiche meso-cenozoi-
che. In: Accordi G, Carbone F (eds) Note illustrative alla carta
delle litofacies del Lazio-Abruzzo ed aree limitrofe, vol 114.
CNR Quaderni de ‘‘La Ricerca Scientifica’’, pp 11–92
Bernoulli D (2001) Mesozoic–Tertiary carbonate platforms, slopes
and basins of the external Apennines and Sicily. In: Vai GB,
Martini IP (eds) Anatomy of an orogen: the Apennines and
Adjacent Mediterranean Basins. Kluwer Academic Publishers,
Dordrecht, pp 307–326
Borgomano JRF (2000) The Upper Cretaceous carbonates of the
Gargano-Muge region, southern Italy: a model of platform-to-
basin transition. AAPG Bull 84:1561–1588
Carannante G, Ruberti D, Simone L (1993) Rudists and related
sediments in Late Cretaceous open-shelf settings. A case history
from Matese area (Central Apennines, Italy). G Geol 55:21–36
Carannante G, Cherchi A, Simone L (1995) Chlorozoan versus
foramol lithofacies in Late Cretaceous rudist limestones. Palae-
ogeogr Palaeoclimatol Palaeoecol 119:137–154
Carannante G, Graziano R, Ruberti D, Simone L (1997) Upper
Cretaceous temperate-type open shelves from northern (Sardi-
nia) and southern (Apennines–Apulia) Mesozoic Tethyan mar-
gins. In: James NP, Clarke JAD (eds) Cool-water carbonates, vol
56. Society of Economic Paleontologists and Mineralogists,
Tulsa, OK, USA, p 309–325
Carannante G, Graziano R, Pappone G, Ruberti D, Simone L (1999)
Depositional system and response to sea-level oscillation of the
Senonian foramol-shelves. Examples from central Mediterranean
areas. Facies 40:1–24
Carannante G, Ruberti D, Sirna M (2000) Upper Cretaceous low-
energy ramp limestones from the Sorrento Peninsula (Southern
Apennines, Italy): micro- and macrofossil associations and their
significance in the depositional sequences. Sediment Geol
132:89–124
Carannante G, Ruberti D, Simone L (2003) Sedimentological and
taphonomic characterization of low-energy rudist-dominated
Senonian carbonate shelves (Southern Apennines, Italy): a North
African perspective. In: Gili E, Negra MH, Skelton PW (eds)
North African Cretaceous rudist and coral formations and their
contributions to carbonate platform development. NATO ASI
Series. Kluwer, Dordrecht, pp 189–201
Carminati E, Corda L, Mariotti G, Brandano M (2007) Tectonic
control on the architecture of a Miocene carbonate ramp in the
Central Apennines (Italy): insights from facies and backstripping
analyses. Sediment Geol 198:233–254
Carminati E, Lustrino M, Cuffaro M, Doglioni C (2010) Tectonics,
magmatism and geodynamics of Italy: what we know and what
we imagine. In: Beltrando M, Peccerillo A, Mattei M, Conticelli
S, Doglioni C (eds) The geology of Italy: tectonics and life along
plate margins. J Virtual Explorer 36. doi:10.3809/jvirtex.2010.
00226
Cestari R, Pons JM (2004) Coniacian–Santonian rudist facies in Cilento
(southern Italy). In: Hofling R (ed) Contributions to the 5th
international congress on rudists held in Erlangen, Germany 1999.
Courier Forschungsinstitut Senckenberg, vol 247. pp 175–192
Checconi A, Rettori R, Spalluto L (2008) Biostratigrafia a foramini-
feri del Cretaceo Superiore della successione di Parco Priore
(Calcare di Altamura, Piattaforma Apula, Italia Meridionale).
Annali dell’Universita degli Studi di Ferrara Museologia Scien-
tifica e Naturalistica 4:1–11
Chiocchini M, Mancinelli A (1978) Ricerche geologiche del Gran Sasso
d’Italia (Abruzzo). III. Correlazioni microbiostratigrafiche tra
facies di margine della piattaforma carbonatica e facies pelagiche
del Giurassico e Cretaceo inferiore. Studi Geol Camerti 4:19–36
Chiocchini M, Mancinelli A (2001) Sivasella monolateralis Sirel and
Gunduz, 1978 (Foraminiferida) in the Maastrichtian of Latium
(Italy). Rev Micropaleontol 44:267–277
Chiocchini M, Farinacci A, Mancinelli A, Molinari V, Potetti M
(1994) Biostratigrafia a foraminiferi, dasicladali e calpionelle
delle successioni carbonatiche mesozoiche dell’Appennino cent-
rale (Italia). In: Mancinelli A (ed) Biostratigrafia dell’Italia
centrale, Studi Geol Camerti, vol spec 9. pp 1–129
Chiocchini M, Chiocchini RA, Didaskalou P, Potetti M (2008)
Microbiostratigrafia del Triassico superiore, Giurassico e Cre-
taceo in facies di piattaforma carbonatica del Lazio centro-
meridionale e Abruzzo: revisione finale. Mem Descr Carta Geol
It 84:5–170
Civitelli G, Brandano M (2005) Atlante delle litofacies e modello
deposizionale dei Calcari a Briozoi e Litotamni nella Piattaforma
carbonatica laziale-abruzzese. Bollettino della Societa Geologica
Italiana 124:611–643
Civitelli G, Mariotti G (1975) Paleontological and sedimentological
characteristic of the Senonian of Pietrasecca (Carseolani Moun-
tains, Central Apennines). Geol Romana 14:87–124
Colombie C, Strasser A (2005) Facies, cycles, and controls on the
evolution of a keep-up carbonate platform (Kimmeridgian, Swiss
Jura). Sedimentology 52:1207–1227
Dunham RJ (1962) Classification of carbonate rocks according to
depositional texture. In: Hamm WE (ed) Classification of
carbonate rocks, a symposium. AAPG Memoir 1, pp 108–121
Eberli GP, Bernoulli D, Sanders D, Vecsei A (1993) From aggrada-
tion to progradation: the Maiella Platform, Abruzzi Italy. In:
Simo T, Scott RW, Masse JP (eds) Cretaceous carbonate
platforms. AAPG Memoir 56, pp 213–237
Embry AF, Klovan JE (1971) A Late Devonian reef tract on
Northeastern Banks Island, Northwest Territories. Bull Can Pet
Geol 19:730–781
Flugel E (2004) Microfacies of carbonate rocks: analysis, interpre-
tation and application. Springer, Berlin Heidelberg New York
Gili E, Masse JP, Skelton PW (1995) Rudists as gregarious sediment-
dwellers, not reefbuilders, on Cretaceous carbonate platforms.
Palaeogeogr Palaeoclimatol Palaeoecol 118:245–267
Facies (2014) 60:489–500 499
123
Gueguen E, Doglioni C, Fernandez M (1998) On the post-25 Ma
geodynamic evolution of the Western Mediterranean. Tectono-
physics 298:259–269
Hallock P (1979) Trends in test shape with depth in large, symbiont-
bearing foraminifera. J Foraminifer Res 9:61–69
Hallock P (1983) Larger foraminifera as depth indicators in carbonate
depositional environments. AAPG Bull 67:477–478
Hardie LA, Ginsburg RN (1977) Layering: the origin and environ-
mental significance of lamination and thin bedding. In: Hardie
LA (ed) Sedimentation on the modem carbonate tidal flats of
Northwest Andros Island. Bahamas. The Johns Hopkins Uni-
versity Press, Baltimore, pp 50–123
Insalaco E (1998) The descriptive nomenclature and classification of
growth fabrics in fossil scleractinian reefs. Sediment Geol
118:159–186
Joachimski MM (1994) Subaerial exposure and deposition of
shallowing-upward sequences: evidence from stable isotopes of
Purbeckian peritidal carbonates (basal Cretaceous), Swiss and
French Jura Mountains. Sedimentology 41:805–824
Johnson CC, Sanders D, Kauffman E, Hay WW (2002) Patterns and
processes influencing Upper Cretaceous reefs. In: Kiessling W,
Flugel E, Golonca J (eds) Phanerozoic reef patterns, vol 72.
SEPM (Society for Sedimentary Geology), pp 549–85 (Special
Publication)
Kidwell SM, Holland SM (1991) Field description of coarse
bioclastic fabrics. Palaios 6:426–434
Mariotti G (1982) Alcune facies a Rudiste dei Monti Carseolani:
descrizione e correlazione dal bordo occidentale all’interno della
Piattaforma Laziale-Abruzzese. Geol Romana 21:885–902
Molinari-Paganelli V, Tilia-Zuccari A (1987) Benthic foraminifera
horizons in the Late Cretaceous platform carbonates of the
Central Apennines (Latium, Italy). Mem Soc Geol Italy
40:175–186
Parotto M, Praturlon A (2004) The Southern Apennine Arc. In:
Crescenti V, D’Offizi S, Merlino S, Sacchi L (eds) Geology of
Italy, Italian Geology Society Special Volume for the IGC 32,
pp 33–58
Pomar L, Hallock P (2008) Carbonate factories: a conundrum in
sedimentary geology. Earth Sci Rev 87:134–169
Pomar L, Gili E, Obrador A, Ward WC (2005) Facies architecture and
high-resolution sequence stratigraphy of an upper Cretaceous
platform margin succession, Southern Central Pyrenees, Spain.
Sediment Geol 175:339–365
Ruberti D, Toscano F, Carannante G, Simone L (2006) Rudist
lithosomes related to current pathways in Upper Cretaceous
temperate-type, inner shelves: a case study from the Cilento area,
southern Italy. In: Pedley HM, Carannante G (eds) Cool-water
carbonates: depositional systems and palaeoenvironmental con-
trols, vol 255. Geological Society, London, pp 179–195 (Special
Publications)
Sgrosso I (1968) Note biostratigrafiche sul M. Vesole (Cilento).
Bollettino della Societa naturale in Napoli 77:159–180
Simone L, Carannante G, Ruberti D, Sirna M, Sirna G, Laviano A,
Tropeano M (2003) Rudist-rich bodies development and growth
in central-southern Italy early Senonian carbonate shelves: high-
energy vs low-energy settings. Palaeogeogr Palaeoclimatol
Palaeoecol 200:5–29
Skelton PW (1978) The evolution of functional design in rudists
(Hippuritacea) and its taxonomic implications. Philos Trans R
Soc Lond B 284:305–318
Skelton PW, Gili E (1991) Palaeoecologic classification of rudist
morphotypes. In: Sladic-Trifunovic M (ed) First international
conference on rudists, October 1988. Proceedings Serbian
Geological Society, vol 2. Beograd, pp 1–86 (Special Publication)
Skelton PW, Gili E, Vicens E, Obrador A (1995) The growth fabric of
gregarious rudist elevators (hippuritids) in a Santonian carbonate
platform in the southern Central Pyrenees. Palaeogeogr Palae-
oclimatol Palaeoecol 119:107–126
Stossel I, Bernoulli D (2000) Rudist lithosome development on the
Maiella carbonate platform margin. In: Insalaco E, Skelton PW,
Palmer TJ (eds) Carbonate platform system components and
interactions, vol 178. Geological Society, London, pp 177–190
(Special Publications)
Strasser A, Vedrine S (2009) Controls on facies mosaics of carbonate
platforms: a case study from the Oxfordian of the Swiss Jura. In:
Swart P, Eberli G, McKenzie J (eds) Perspectives in carbonate
geology, vol 41. pp 199–213 (IAS Special Publications)
Tesovic B, Gusic I, Jelaska V, Buckovic D (2001) Stratigraphy and
microfacies of the Upper Cretaceous Pucisc a Formation, Island
of Brac, Croatia. Cretac Res 22:591–613
Wilson JL (1975) Carbonate facies in geologic history. Springer,
Berlin Heidelberg New York
Wright VP, Burgess PM (2005) The carbonate factory continuum,
facies mosaics and microfacies: an appraisal of some of the key
concepts underpinning carbonate sedimentology. Facies 51:19–25
500 Facies (2014) 60:489–500
123