background image

GEOLOGICA CARPATHICA, OCTOBER 2005, 56, 5, 407—414

www.geologicacarpathica.sk

The origin of coarsening-upward cycle architecture;

an example from Middle Liassic platform carbonates of

mountain Velika Kapela (Croatia)

DAMIR BUCKOVIĆ, BLANKA CVETKO TEŠOVIĆ and ALEKSANDAR MEZGA

Department of Geology and Paleontology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia;

damir.buckovic@zg.t-com.hr

(Manuscript received July 15, 2004; accepted in revised form March 17, 2005)

Abstract:  The  Middle Liassic carbonate succession of Mt Velika Kapela is composed of coarsening-upward cycles.
Analysis of facies alternation and stacking pattern reveals a sporadic appearance of oolitic facies indicating oolitic shoal
progradation from neighbouring topographic highs. These progradations interrupted the constant “in situ” carbonate
sediment aggradation, which produced typical coarsening-upward architecture. Two types of coarsening-upward cycles
were distinguished: 1 – cycles with peloidal-bioclastic upper cycle members, and 2 – cycles with oolitic upper cycle
members. These coarsening-upward cycles are regarded as a record of the sea-bottom oscillations below and above the
fair-weather wave-base and model for evolution and cyclic response of carbonate facies to these oscillations is presented.

Key words: Croatia, Adriatic-Dinaric carbonate platform, autocyclicity, carbonate sedimentology, Middle Liassic
limestones, facies analysis.

Introduction

This paper is the result of our frequent encounters with
Middle Liassic cyclic sedimentary signatures throughout
the Karst Dinarides platform area. Numerous studies of
the effects of high-frequency relative sea-level changes
in carbonates show that cycles are excellent indicators of
sea-level fluctuations because their formation is highly
dependent on many variable parameters (Hays et al.
1976; Goodwin & Anderson 1985; Grotzinger 1986;
Goldhammer et al. 1990; Gonzales 1996; Strasser et al.
1999; Egenhoff et al. 1999). Thus, the cycle architecture
depends on environmental factors that change periodi-
cally causing rapid facies changes through time. These
facies changes occur when a physical, chemical, and / o r
biological treshold is passed, and when the sediment ac-
quires a new composition and texture (Strasser et al.
1999). This study represents an attempt to interpret Mid-
dle Liassic coarsening-upward cycles. We have chosen a
Middle Liassic interval from Mt Velika Kapela (Croatia)
because it represents a depositional sequence revealing
typical facies alternations with successive and repeated
coarsening-upward trends, typical for the Middle Liassic
succession of the Karst Dinarides.

Geological setting

The studied profile of Middle Liassic limestones is

well exposed along the road between Jasenak and Novi
Vinodolski at Mt Velika Kapela (Fig. 1). This area rep-
resents the western part of the Karst Dinaridic platform
area. Due to its complex geological history, there are

different opinions among Croatian geologists concern-
ing two important issues: (a) the name of the Karst
Dinaridic platform area and, (b) its stratigraphic range.
Gušić & Jelaska (1993), Jelaska et al. (1994, 2000), and
Jelaska (2003) consider that the depositional  area of the
Karst Dinarides belongs to the Adriatic-Dinaric carbon-
ate platform area (ADCP), with its lower boundary
marked by a regional unconformity between the Haupt-
dolomit and various pre-Norian units. On the other
hand, Tišljar et al. (1991) and Velić (2000) regard the
depositional area of the Karst Dinarides as belonging to
the Adriatic carbonate platform (ACP), where the
Hauptdolomit would represent only the lower boundary
of the second ACP megasequence and the entire ACP
sequence would extend from the Upper Paleozoic to Pa-
leogene (Tišljar et al. 1991; Velić 2000). However, we
prefer to use the name “Adriatic-Dinaric carbonate plat-
form (ADCP)” in the sense proposed and elaborated by
Jelaska (2003). A more detailed explanation of our
choice is beyond the scope of this paper (see Velić et al.
2003; Jelaska 2003).

Until the Middle Triassic, the area of what is to be-

come the Adriatic-Dinaric carbonate platform, repre-
sented a part of the northern Gondwana shelf area,
characterized by deposition of siliciclastics and carbon-
ates. During the Middle Triassic, disintegration of the
shelf foundation and separation of a huge shallow-water
shelf fragment named the Adria Microplate took place
within the Tethyan realm (Bernoulli & Jenkyns 1974).
During the late Early Jurassic, the Adria Microplate dis-
integrated, resulting in the formation of three shallow-
water areas mutually separated by deep-water basins.
These were the Adriatic-Dinaric, Apenninic, and  Apulian

background image

408                                                                   BUCKOVIĆ, CVETKO TEŠOVIĆ and MEZGA

carbonate platforms separated by the Adriatic and Mo-
lise-Lagonero Basins (Velić et al. 2003). From the late
Early Jurassic until the end of the Cretaceous, succes-
sive series of shallow-water limestones were deposited pre-
dominantly on the Adriatic-Dinaric platform area.

General characteristics of the Karst Dinaridic

Liassic limestones

The Karst Dinaridic  Liassic limestones reveal an infor-

mal tripartite division (Fig. 2a) (Velić 1977): 1 – The
Lower Liassic succession is characterized by the stacking
of autocyclic parasequences, that is successive series of
coarsening- and shallowing-upward cycles with cycle
members of variable thickness and abundant emersion sur-
faces (Bucković et al. 2001). The thickness of the lower cy-
cle members ranges from 0.9 to 1.8, whereas the upper cycle
members vary from 0.3 to 0.5 m in thickness. Sporadically,
the upper members may be dolomitized. 2  – Similar tex-
tural features also characterize the onset of the Middle Li-
assic complex. Additionally, the upper part of the Middle
Liassic succession is usually marked with more or less
common biostromes containing large “Lithiotis” bivalve
shells. These biostromes vary in thickness from 10—70 cm
and are present in many Karst Dinaridic Middle Liassic lo-

Fig. 1. Geographical location of the studied succession (studied profile is exposed along the shaded part of the road). Geological sketch
according to Basic Geological Map 1:100,000, sheet Crikvenica (Šušnjar et al. 1970) (modified). T

3

 – Upper Triassic, J

1

1

  – Lower

Lias, J

1

2

 – Middle Lias, J

1

3

 – Upper Lias, J

2

 – Dogger, J

3

1

 – Lower Malm.

calities, but in some places, they are lacking. However, the
Middle Liassic succession described in this paper contains
no “Lithiotis” biostromes, so their more detailed descrip-
tion will be given elsewhere. 3 – The Upper Liassic
“Spotted Limestones” are mud-rich and mostly intensely
bioturbated with small, indeterminable bioclasts. In places,
some thicker packages of the “spotty” successions are
build up of coarsening-upward cycles, with upper cycle
members dolomitized or showing emersion features.
Throughout the Karst Dinarides, Lower Jurassic limestone
successions are sporadically interrupted with thinner or
thicker dolomitic lenses and intervals.

Description of studied Middle Liassic coarsening-upward
cycles

The Middle Liassic successions are predominantly

composed of series of coarsening-upward cycles. The cy-
clic stacking pattern always reveals very similar charac-
teristics. Two coarsening-upward cycle types can be
recognized:  1 – cycles with peloidal-bioclastic upper
cycle members, and 2 – cycles with oolitic upper cycle
members. As this cycle architecture is commonly present
within the entire Middle Liassic Karst Dinaridic area, we
considered in detail only one interval from Mt Velika
Kapela (Croatia) that amounts to ca. 325 m (Figs. 1 and 2a).

background image

COARSENING-UPWARD CYCLE ARCHITECTURE OF MIDDLE LIASSIC CARBONATES (CROATIA)                     409

Cycles with peloidal-bioclastic upper cycle members

These coarsening-upward cycles contain mudstone or

peloidal-bioclastic wackestone as the lower cycle mem-
bers (Fig. 2b). The thickness of the lower cycle members
varies from 0.7—2 m, whereas the upper cycle members
range from 0.1—0.6 m. Mudstones and peloidal-bioclastic
wackestones are composed of micrite with variable
amounts of peloids, molluscan and ostracode fragments
and individual benthic foraminifers (Fig. 3). Separate
LLH (Laterally Linked Hemispheroids) stromatolitic lami-
nae and laminoid fenestrae are sporadically present. Bio-
turbation occurs locally. Within these mud-rich limestone
types, intercalations of horizontally laminated peloidal-
bioclastic packstone-grainstone, 0.1—0.3 m thick, can oc-
casionally be found (Fig. 4). Single horizontal 1—3 mm
thick laminae are graded. These intercalations are always
separated at their bottom by sharp, erosional surfaces.
They have gradational upper boundaries into overlying
mudstones or wackestones. Peloids, foraminifers, small

Fig. 2. a – Lithofacies column of Mt Velika Kapela Liassic limestones. b – Lithofacies column with typical series of few Middle Lias-
sic coarsening-upward cycles (in scale from the field).

echinoid and ostracode fragments embedded in micrite
and/or drusy cement dominate. Elongated bioclasts are al-
ways oriented parallel to bedding.

Coarse-grained particles are present within upper cycle

members (Fig. 2b). These wackestone/packstones to grain-
stones are abundant in peloids, coarser molluscan and spo-
radic echinoderm bioclasts (Fig. 5). More rarely, they
contain subrounded micritic intraclasts and concentric on-
coids with bioclastic nuclei surrounded by few cryptocrys-
talline envelopes. Coarser-grained bioclasts are always
more or less recrystallized and randomly oriented. Some
beds contain rich foraminiferal debris. They are best dated
by the occurrence of the foraminifers Orbitopsella prae-
cursor  (Gümbel) (Figs. 5a and 6a) and Lituosepta com-
pressa  Hottinger (Fig. 6b), important biostratigraphic
markers in the Tethyan realm. Other foraminifers, includ-
ing  Amijella amiji Henson, Mayncina termieri Hottinger,
Haurania deserta Henson, “Siphovalvulina” (Fig. 5d) as
well as algae Palaeodasycladus  ex gr. mediterraneus (Pia)
(Fig. 6c), 

Thaumatoporella parvovesiculifera (Raineri)

background image

410                                                                   BUCKOVIĆ, CVETKO TEŠOVIĆ and MEZGA

and  Cayeuxia sp., can also be sporadically found. Various
textulariids and verneuilinids are commonly present but
have no biostratigraphic significance. In places, horizon-
tal lamination is present, when sharp and uneven erosional
contacts with underlying unlaminated beds are visible.

By periodically changing conditions, from low-energy

shallow subtidal to higher-energy subtidal above the fair-
weather wave-base, a series of coarsening-upward cycles
have been produced. During low-energy shallow subtidal
conditions with slow and constant rate of sediment accu-
mulation, a large amount of carbonate mud with rare bio-
clasts was deposited. A much more intensive production
of various coarser-grained particles occurred during peri-
odical subtidal shallowing above the fair-weather wave-
base (see Discussion). Sporadic horizontal lamination
observed within the packstone-grainstone intercalations
and even wackestone/packstone to grainstone beds was
formed during periods of intensive unidirectional tidal
and/or storm currents. These currents eroded the subtidal
bottom, winnowed the muddy peloidal-bioclastic materi-
al, removed the carbonate mud, oriented elongated bio-
clasts parallel to bedding, and formed the horizontal,
graded laminae.

Fig. 3. Peloidal-bioclastic wackestone. Scale bar 1.6 mm.

Fig. 4. Contact between peloidal-bioclastic wackestone and peloi-
dal-bioclastic grainstone. Scale bar 1.6 mm.

Fig. 5. Peloidal-bioclastic grainstone with Orbitopsella praecursor
(Gümbel), (a), and “Siphovalvulina”, (d). Scale bar 1.6 mm.

Fig. 6. Peloidal-bioclastic grainstone with Orbitopsella praecursor
(Gümbel), (a), Lituosepta compressa Hottinger, (b), and Palaeo-
dasycladus ex. gr. mediterraneus (Pia), (c). Scale bar 1.6 mm.

Cycles with oolitic and oolitic-bioclastic upper cycle

members

The same features as were described in the previous

chapter characterize mudstones or peloidal-bioclastic
wackestones as the lower members of these cycles. Howev-
er, their thicknesses are generally smaller, amounting to
0.4—1.1 m. The upper cycle member is represented by ooid
grainstones and/or ooid-bioclastic packstones to grain-
stones (Fig. 2b). Ooid grainstones consist of well-sorted
ooids with peloidal or bioclastic nuclei, surrounded by an
envelope of radial fibrous fabric (Fig. 7). The ooids are
white to cream in colour, have a pearly lustre, and usually
range in size from 0.2 mm to 1.0 mm. They have frequent-
ly recrystallized envelopes and even nuclei. The diagene-
sis of these grainstones includes fibrous calcite on the
surface of the ooids and drusy calcite spar in the intergran-
ular pores. Sporadically, pore spaces are filled up by crys-
tal silt. Among the ooids there are sporadic small
molluscan fragments and foraminiferal tests. Distinct
cross- and/or horizontal lamination can be sporadically
observed. However, these structures are mostly hard to
recognize because of the well-sorted nature of the

background image

COARSENING-UPWARD CYCLE ARCHITECTURE OF MIDDLE LIASSIC CARBONATES (CROATIA)                     411

Fig. 7. Ooid grainstone. Scale bar 0.8 mm.

Fig. 8. Ooid-bioclastic grainstone. Scale bar 1.6 mm.

grainstones. The bases of oolitic members are common-
ly erosional surfaces. In drusy calcite spar or micritic
matrix the ooid-bioclastic packstones to grainstones
contain ooids and variety of poorly sorted, abraded and
broken molluscan, echinoderm and hydrozoan frag-
ments, as well as variously sized intraclasts (Fig. 8).
Elongated coarser-grained particles are mostly random-
ly oriented.

These cycles also represent a sedimentary response to

cyclic environmental changes from low-energy shallow
subtidal to higher-energy subtidal above the fair-weath-
er wave-base. However, environmental conditions dur-
ing the formation of the oolitic upper cycle members
were different compared with the conditions in which
peloidal-bioclastic upper cycle members were deposit-
ed (see Discussion). At first glance it is recognized by
the frequent erosional surfaces underlying the oolites
and by absence of micrite and peloids. That implies
shallower and higher energy subtidal conditions of
oolitic shoals, which migrated laterally over the rela-
tively deeper subtidal environments. Their migration
by tidal and/or storm currents of different energy led to
formation of sporadic cross- and/or horizontal lamina-
tion. Rare findings of crystal silt in pore spaces of oo-
lites indicate the neighbouring presence of the vadose
zone from which calcite crystals were washed and trans-
ported in suspension to the oolitic shoals.

Discussion

The high-frequency cycles described in this study are

usually referred to as parasequences (Goldhammer et al.
1990). They are often interpreted to be of allocyclic origin
and to be caused by climatic fluctuations associated with
Milankovitch cycles (Vail et al. 1991). Milankovitch cy-
cles are orbital cycles, which modulate insolation and are
commonly related to fluctuations of climate, whereby the
waxing and waning of ice caps, especially during glacia-
tions (such as nowadays), act as amplifier of the inherently
weak insolation signal. Orbitally controlled waxing and
waning of ice caps translate into high-frequency sea-level

fluctuations, which may lead to metre-scale shallowing-
and coarsening upward cycles (e.g. Strasser 1991; Gold-
hammer et al. 1993; Strasser et al. 1999). However, it is
difficult to correlate here studied cycles with Milanko-
vitch cycles because during the Jurassic, ice in high lati-
tudes was probably present, but ice-volumes were not
sufficient to induce important glacio-eustatic fluctuations
(Frakes et al. 1992; Eyles 1993; Valdes et al. 1995), al-
though volume changes of alpine glaciers could make a
small contribution (Fairbridge 1976; Valdes et al. 1995).
Additionally, the Early Jurassic was a time of climatic
warming (Hallam & Wignall 1999), because of rapid rise
in CO

2

 levels caused by the outpouring of the Central At-

lantic Magmatic Province as a result of the rifting of Pan-
gea (Nance & Murphy 1994; Marzoli et al. 1999). In such
circumstances, there was probably no pronounced season-
ality during the Early Jurassic. However, we assume that
high-frequency sea-level fluctuations of allocyclic origin
were present during the Early Jurassic, but were small and
thus hardly perceptible in the sedimentary record. There-
fore, predominantly based on the sedimentary mechanisms
active in platform shallow-water environments, we inter-
pret the ADCP Middle Liassic coarsening-upward cycles
as being the result of autocyclic processes, but having in
mind that some allocyclic signal was also present, but for
the time being hard to recognize.

Large carbonate platforms, without prominent elevation

differences, are characterized by small water depths (main-
ly less than 10 m), and the fair-weather wave-base at less
than 5 m (Tucker & Wright 1990). Judging from this, one
can presume that successive series of coarsening-upward
cycles may be a record of changes in water depth through
varying sediment accumulation, when the sea-bottom
seemingly oscillates around the fair-weather wave-base
(the fair-weather wave-base – FWWB amounts to half of
the wavelength – WL / 2 ). This assumption is based on
two well-known facts: 1 – under optimum conditions car-
bonate sediments can accumulate rapidly, resulting in a
high and mostly constant carbonate production rate
(Smith 1973; Hallock 1981) and 2 – carbonate produc-
tion in modern depositional environments, as a rule, ex-
ceeds the average amount of platform subsidence and

background image

412                                                                   BUCKOVIĆ, CVETKO TEŠOVIĆ and MEZGA

moderate eustatic sea-level rise (Tucker & Wright 1990).
The typical sedimentation rate of modern carbonate de-
posits is 1 m per 1000 yr, typical subsidence rates of pas-
sive continental margins, where many ancient carbonate
platforms developed, are 0.01—0.1 m per 1000 yr, and
typical eustaic sea-level changes are 0.01 m per 1000 yr
(Tucker & Wright 1990). Rapid subsidence, generally
fault-induced and major sea-level rises through glacial
melting, are not included. From these, it can be presumed
that the facies differences, that is the cycle architecture,
observed in the examined Middle Liassic strata, are main-
ly the result of processes operating within the ADCP.
Among these processes, aggradation of subtidal carbonate
deposits and progradation of small ooid shoals appear to
be most important.

During periods when the water depth (i.e. accommoda-

tion space) (D) on many ADCP parts was greater than one-
half of the wavelength (D > WL / 2 ), there was no movement
of sediment particles at the sea-bottom (SB) (Fig. 9a). There-
fore, in quiet subtidal environments below the fair-weather
wave-base, peloids and calcareous mud, as well as benthic
foraminifers occasionally associated with various bioclasts,
were predominantly accumulated, producing muddy car-

bonate deposits (Fig. 9c; points 1—2 and 4—5 – tA)
(“catch-up”  phase sensu Kendall & Schlager 1981).

It is presumed that the carbonate production rate ex-

ceeded both the rate of subsidence and the rate of eustatic
sea-level rise (i.e. relative sea-level rise). Such a high car-
bonate accumulation rate caused gradual reduction of ac-
commodation space, that is a decrease of water depth.
When the water depth became less than one-half of the
wavelength (D < WL / 2 ) (Fig. 9b), there were occasional
motions of sediment particles by waves on the sea-bottom.
Under such shallower-water and higher energy conditions,
various coarser-grained calcareous particles were formed,
producing grain supported deposits (Fig. 9c; point 2).
With continuing carbonate production, accommodation
space further decreased and the sea-bottom continues to
aggrade (Fig. 9c; points 2—3 – tB) (“keep-up” phase sen-
su Kendall & Schlager 1981). Yet, such environment with
agitated water, supersaturated with CaCO

3

, became un-

favourable for the majority of carbonate-producing benthic
organisms (e.g. foraminifers, mollusks). Highly oxygenated
pore waters and high water exchange rates also enhanced
the process of cementation. Under such conditions, the
rate of new carbonate sediment production slowed down,

Fig. 9. A model for the origin of coarsening-upward cycle architecture (Bucković 2001, modified). tA (1—2,  4—5) – “catch-up” phase,
tB (2—3, 5—6) – “keep-up” phase, 3—4 – lag phase, progradation, 4 – “start-up” phase, FWWB – fair-weather wave-base, SL – sea-level,
SB – sea-bottom, D – water depth, WL – wavelength, t – time, M – mudstone, W – wackestone, P – packstone, G – grainstone.

background image

COARSENING-UPWARD CYCLE ARCHITECTURE OF MIDDLE LIASSIC CARBONATES (CROATIA)                     413

so that the carbonate accumulation was easily outpaced
by continued relative sea-level rise, and the sea-bottom
was lowered below the fair-weather wave-base (Fig. 9c;
points 3—4 – lag). After this “lag phase” (Read et al.
1986; Schlager 1992), carbonate-producing organisms
(mostly mass faecal pellets producers, e.g. worms, ostra-
codes, gastropods) colonized the sea-bottom drowned be-
low the fair-weather wave-base, and carbonate production
was re-established (Fig. 9c; point 4) (“start-up” phase sensu
Kendall & Schlager 1981; or “log phase” sensu Schlager
1992); a new cycle with a muddy lower member started to
accumulate (Fig. 9c; points 4—5) (“catch-up” phase sensu
Kendall & Schlager 1981). Such autocyclic mechanism
would explain the origin of the coarsening-upward cycles
with peloidal-bioclastic upper cycle members.

In contrast to that, environmental conditions within

sporadically presented subtidal topographic highs were
rather different (Fig. 9d—f). In these places, the water depth
was smaller and the wavelength was consequently short-
ened, so the sea-bottom (SB) was positioned closer to the
fair-weather wave-base (FWWB) (Fig. 9d). Thus, when the
water depth became less than one-half of the wavelength
(D < WL / 2 ), water temperature and pH as well as the car-
bonate saturation level and water energy increased,
favouring the formation of ooids (e.g. Gonzales 1996)
(Fig. 9e). In such conditions, the ooids were in constant
motion allowing them to grow around a nucleus forming
an oolitic shoal. With continuing production of ooids the
accommodation space decreased (Fig. 9f; points 2—3 – tB).
When oolitic shoals aggraded close to the sea level, they
began to prograde laterally (Fig. 9f; points 3—4) under in-
fluence of tidal and / o r storm currents (when distinct
cross- and/or horizontal lamination was formed), covering
the adjacent deposits below and/or above the fair-weather
wave-base and forming the coarsening-upward cycles with
distinct upper oolitic and /or oolitic-bioclastic cycle mem-
bers. Therefore, the occurrence of cycles with ooids re-
flects the oolitic shoal progradations. These oolitic shoal
progradations were random, episodic processes depending
on physical factors working in the sedimentary environ-
ment. Among those, the most important was the formation
of subtidal topographic highs on which the water depth
was reduced (see above for explanation). The topographic
highs in the shallow Middle Liassic ADCP realm would
develop through sediment trapping by organisms (e.g.
fleshy algae), or through slight tectonic uplifts. However,
as evidence for the formation of barriers through sediment
trapping in the investigated Middle Liassic succession
was not noticed, we assume that small-scale synsedimenta-
ry uplifts were a more likely scenario. These small-scale
uplifts were random events, with no predictable periodici-
ty and place of occurrence. Thus, in periods when oolitic
shoals prograded over the subtidal below the fair-weather
wave-base, one coarsening-upward cycle with ooid grain-
stone as the upper cycle member was formed. Analogous-
ly, in periods when oolitic shoals prograded over the
subtidal above the fair-weather wave-base, one coarsen-
ing-upward cycle with ooid-bioclastic packstones to
grainstones as the upper cycle member was formed. In pe-

riods when high energy storm events triggered prograda-
tion, that is rapid migration of oolites, these currents suc-
ceeded in eroding subtidal bottom when erosive bases of
the oolites were formed.

During periods without oolitic shoal progradations,

only vertical aggradation of subtidal carbonate deposits
occurred, producing successive series of coarsening-upward
cycles with peloidal-bioclastic upper cycle members.

Conclusion

The studied Middle Liassic sedimentary succession has

been formed within the interior of the isolated Adriatic-Di-
naric carbonate platform area. It reveals successive coars-
ening-upward trend from the subtidal below the
fair-weather wave-base to the subtidal above the fair-
weather wave-base as the predominant response to the au-
tocyclicity in the sedimentary environment. Gradual
aggradation of the muddy carbonate material, deposited
below the fair-weather wave-base reduced the accommo-
dation space, causing the sea-bottom to rise above the fair-
weather wave-base. Here, more grainy carbonates were
deposited, creating one coarsening upward cycle with
mudstones or peloidal-bioclastic wackestones as the lower
cycle member and peloidal-bioclastic wackestone/pack-
stones to grainstones as the upper cycle member. During
the “lag phase”, the sea-bottom has sunk below the fair-
weather wave-base, which enabled the formation of the
next coarsening-upward cycle. The progradations of
neighbouring oolitic shoals periodically and randomly in-
terrupted this process. Oolitic shoals, sporadically formed
on topographic highs within the subtidal area, prograded
over the surrounding environment below or above the fair-
weather wave-base, producing sporadic coarsening-up-
ward cycles with ooid grainstones and /or ooid-bioclastic
packstones to grainstones as the upper cycle member.

Therefore, the Middle Liassic coarsening-upward archi-

tecture of Mt Velika Kapela resulted from interplay of re-
peated sediment aggradations, interrupted by periodical
and random oolitic shoal progradations.

Acknowledgments:  We thank Professor André Strasser,
Doc. Jozef Michalík and one anonymous reviewer for
stimulating reviews that improved the original manu-
script. This research is supported by the Ministry of Sci-
ence, Education and Sport of the Republic of Croatia
(Project No. 119306).

References

Bucković D., Jelaska V. & Cvetko Tešović B. 2001: Facies variabil-

ity in Lower Liassic carbonate succession of the Western Di-
narides (Croatia). Facies  44, 151—162.

Bernoulli D. & Jenkyns H.C. 1974: Alpine, Mediterranean and cen-

tral Atlantic Mesozoic facies in relation to the early evolution
of Tethys. In: Dott R.H. & Shaver R.H. (Eds.): Modern and
ancient geosynclinal sedimentation. Soc. Econ. Paleont.

background image

414                                                                   BUCKOVIĆ, CVETKO TEŠOVIĆ and MEZGA

Mineral. Spec. Publ. 18, 129—160.

Egenhoff S.O., Peterhänsel A., Bechstädt T., Zühlke R. & Grötsch

J. 1999: Facies architecture of an isolated carbonate plat-
form: tracing the cycles of the Latemar (Middle Triassic,
northern Italy). Sedimentology 46, 893—912.

Eyles N. 1993: Earth’s glacial record and its tectonic setting.

Earth Sci. Rev. 35, 1—248.

Fairbridge R.E. 1976: Convergence of evidence on climatic

change and ice ages. Ann. N.Y. Acad. Sci. 91, 542—579.

Frakes  L.A., Francis J.E. & Syktus J.I. 1992: Climate Modes of

the Phanerozoic. Cambridge Univ. Press, 1—274.

Goldhammer R.K., Oswald E.J. & Dunn P.A. 1990: Forward

modeling of high-frequency, depositional sequences: an ex-
ample from Middle Pennsylvanian shelf carbonates of the
SW Paradox Basin, Honnacker Trail, Utah. Abstr. Amer. As-
soc. Petrol. Geol. Bull. 74, 663.

Goldhammer R.K., Dunn P.A. & Hardie L.A. 1993: Depositional

cycles, composite sea-level changes, cycle stacking patterns,
and the hierarchy of stratigraphic forcing: examples from
Alpine Triassic platform carbonates. Geol. Soc. Amer. Bull.
102, 525—562.

Gonzales R. 1996: Response of shallow-marine carbonate facies

to third-order and high-frequency sea-level fluctuations:
Hauptrogenstein Formation, northern Switzerland. Sed.  Geol.
102, 111—130.

Goodwin P.W. & Anderson E.J. 1985: Punctuated aggradational

cycles: a general hypothesis of episodic stratigraphic accu-
mulation.  J. Geol. 93, 5, 515—533.

Grotzinger J.P. 1986: Cyclicity and paleoenvironmental dynam-

ics, Rocknest platform, northwest Canada. Bull. Geol. Soc.
Amer. 97, 1208—1231.

Gušić I. & Jelaska V. 1993: Upper Cenomanian-Lower Turonian

sea-level rise and its consequence on the Adriatic-Dinaric
carbonate platform. Geol. Rdsch. 82, 4, 676—686.

Hallam A. & Wignall P.B. 1999: Mass extinctions and sea-level

changes.  Earth Sci. Rev. 48, 217—250.

Hallock P. 1981: Production of carbonate sediments by selected

large benthic foraminifera on two Pacific coral reefs. J. Sed.
Petrology 51, 467—474.

Hays J.D., Imbrie J. & Shackleton N.J. 1976: Variations in the

Earth’s orbit: pacemaker of the ice ages. Science 194,
1121—1132.

Jelaska V. 2003: Carbonate Platforms of the External Dinar-

ides. In: Vlahović I. & Tišljar J. (Eds.): Evolution of dep-
ositional environments from the Paleozoic to the
Quaternary in the Karst Dinarides and the Pannonian Ba-
sin.  22

nd

  IAS Meeting of Sedimentology. Field Trip Guide-

book, Opatija, 67—71.

Jelaska V., Gušić I., Jurkovšek B., Ogorelec B., Ćosović V.,

Šribar L. & Toman M. 1994: The Upper Cretaceous geody-
namics evolution of the Adriatic-Dinaric carbonate
platform(s).  Géologie Méditerranéenne 21, 3—4, 89—91.

Jelaska V., Benček D., Matičec D., Belak M. & Gušić I. 2000:

Geological history and structural evolution of the Outer Di-
narides. In: Vlahović I. & Biondić R. (Eds.): 2

nd

 Croatian

Geological Congress. Excursion Guide-Book, Cavtat, 1—12.

Kendall C.G.St.C. & Schlager W. 1981: Carbonates and relative

changes in sea level. Mar. Geol. 44, 181—212.

Marzoli A., Renne P.R., Piccirillo E.M., Ernesto M., Bellieni G.

& De Min A. 1999: Extensive 200-milion-year-old continental

flood basalts of the Central Atlantic Magmatic Province. Sci-
ence 284, 616—618.

Nance R.D. & Murphy J.D. 1994: Orogenic style and the configu-

ration of supercontinents. In: Embry A.F., Beauchamp B.
& Glass D.J. (Eds.): Pangea: global environments and resources.
Canad. Soc. Petrol. Geol. Mem. 17, 49—65.

Read J.P., Grotzinger J.P., Bova J.A. & Koerschner W.F. 1986: Mod-

els for generation of carbonate cycles. Geology 14, 107—110.

Schlager W. 1992: Sedimentology and sequence stratigraphy of

reefs and carbonate platforms. Amer. Assoc. Petrol. Geol.,
Contin. Educ. Course Note Ser. 34.

Smith S.V. 1973: Carbon dioxide dynamics: a record of organic

carbon production, respiration and calcification in the
Enewetak windward reef flat community. Limnol. Oceanogr.
18, 106—120.

Strasser A. 1991: Lagoonal-peritidal sequences in carbonate envi-

ronments: autocyclic and allocyclic processes. In: Einsele G.,
Ricken W. & Seilacher A. (Eds.): Cycles and events in stratig-
raphy.  Springer-Verlag, Berlin, 709—721.

Strasser A., Pittet B., Hillgärtner H. & Pasquier J.B. 1999: Deposi-

tional sequences in shallow carbonate-dominated sedimentary
systems: concepts for a high-resolution analysis. Sed. Geol.
128, 201—221.

Šušnjar M., Bukovac J., Nikler L., Crnolatac I., Milan A., Šikić

D., Grimani I., Vulić Ž. & Blašković I. 1970: Basic geologi-
cal map of Yugoslavia 1:10,000, Crikvenica sheet. Institut za
geološka istraživanja, Zagreb.

Tišljar J., Vlahović I., Sremac J., Velić I., Veseli V. & Stanković D.

1991: Excursion A – Velebit Mt, Permian-Jurassic. In: Velić
I. & Vlahović I. (Eds.): Some aspects of the shallow water sed-
imentation on the Adriatic carbonate platform (Permian to
Eocene).  Sec. Int. Symp. Adriatic carbonate platform. Excur-
sion Guidebook, Zadar, 1—49.

Tucker M.E. & Wright P.V. 1990: Carbon ate sedimentology.

Blackwell, 1—482.

Vail P.R., Audemard F., Bowman S.A., Eisner P.N. & Perez-Cruz

C. 1991: The stratigraphic signatures of tectonics eustasy and
sedimentology – an overview. In: Einsele G., Ricken W.
& Seilacher A. (Eds.): Cycles and events in stratigraphy.
Springer,  Berlin, 617—659.

Valdes P.J., Sellwood B.W. & Price G.D. 1995: Modelling Late Ju-

rassic Milankovitch climate variations. In: House M.R. & Gale
A.S. (Eds.): Orbital forcing timescales and cyclostratigraphy.
Geol. Soc. Spec. Publ. 85, 115—132.

Velić I. 1977: Jurassic and Lower Creaceous assemblege zones in

Mt Velika Kapela, Central Croatia. Acta Geol. 9, 2, 15—37.

Velić I. 2000: The Karst Dinarides: the Adriatic carbonate plat-

form or carbonate pie up to 8.000 m thick, built through the
period of more than 200 millions of years. In: Carulli G.B. &
Longo Salvador G. (Eds.): Riassunti delle comunicazioni
orali e di poster. 80. Riunione Estiva. Soc. Geol. Ital., Tri-
este, 452—455.

Velić I., Tišljar J., Vlahović I., Matičec D. & Bergant S. 2003: Evolu-

tion of the Istrian part of the Adriatic carbonate platform from
the Middle Jurassic to the Santonian and formation of the Flysch
basin during the Eocene: Main events and regional comparison.
In: Vlahović I. & Tišljar J. (Eds.): Evolution of depositional en-
vironments from the Palaeozoic to the Quaternary in the Karst
Dinarides and the Panonian Basin. 22

nd

 IAS Meeting of Sedi-

mentology. Field Trip Guidebook, Opatija, 3—17.