PROVENANCE CHANGES AND SEDIMENTOLOGY OF THE EOCENE
OLIGOCENE MOLDOVIÞA LITHOFACIES OF THE TARCÃU NAPPE
(EASTERN CARPATHIANS, ROMANIA)
LISA GIOCONDA GIGLIUTO
1
, CONSTANTIN GRASU
2
, FRANCESCO LOIACONO
4
,
CRINA MICLÃUª
2
, ELVIO MORETTI
3
, DIEGO PUGLISI
1*
and GIULIANA RAFFAELLI
5
1
Dipartimento di Scienze Geologiche, University of Catania, Corso Italia 55, 95129 Catania, Italy; geolisa@infinito.it; dpuglisi@unict.it
2
Departamentul de Geologie, Al. I. Cuza University of Iaºi, Bd. Carol I, 20A, 6600 Iaºi, Romania; grasuc@ambra.ro; crinam@csc.ro
3
Istituto di Geologia, Campus Universitario, Località Crocicchia, University of Urbino, 61029 Urbino, Italy; elviomoretti@tin.it
4
Dipartimento di Geologia e Geofisica, University of Bari, Via E. Orabona 4, 70125 Bari, Italy; loiacono@geo.uniba.it
5
Istituto di Geodinamica e Sedimentologia, Campus Universitario, Località Crocicchia, University of Urbino, 61029 Urbino, Italy;
g.raffaelli@uniurb.it
*Corresponding Author: Tel: 0039-095-7195724; Fax: 0039-095-7195728; dpuglisi@mbox.unict.it
(Manuscript received March 31, 2003; accepted in revised form October 2, 2003)
Abstract: Lithostratigraphic, sedimentological and petrographic data collected from the lower portion (EoceneOli-
gocene) of the Moldoviþa Lithofacies (near the stratigraphic boundary with the underlying successions of the Tazlãu
Lithofacies) show evidence of a turbidite system characterized by two different sedimentary supplies. Quartzarenite
and litharenite sandstones, in fact, characterize the analysed stratigraphic succession, measured along the Ovãzu River,
near the Ciumârna village (Bucovina region), thus testifying to the existence of two different provenances, linked to
sediment sources tentatively identified with external cratonic areas and with inner crystalline belts together with their
sedimentary cover, respectively. Moreover, the depositional trend, inferred by the facies analysis, shows an arenaceous
interval interpreted as part of an active system (lobe or channel) included in thin and fine-grained facies probably
belonging to fringe or marginal areas. Fine-grained lithofacies with menilite beds, typical of basin plain, are well repre-
sented in the upper part of the succession. Similar turbiditic deposits, but OligoceneMiocene aged, are well known
along the Betic-Maghrebian Chain (Mixed Successions auctorum), where they represent the stratigraphic interference
of two opposite depositional systems closely linked to the starting of the tectogenesis preluding the closure of the
Maghrebian Flysch Basin. Nevertheless, the analysed succession, very similar in composition and in textural characters to
the Betic-Maghrebian Mixed Successions, cannot assume the same significance. In this case, in fact, we suppose that the
studied succession could be linked to a peculiar paleogeographical morphology of the sedimentary basin, excluding that
tectonic events could have been the main control factors of the interaction of the two recognized different depositional
systems, owing to the EoceneOligocene age of the lower portion of the Moldoviþa Lithofacies, here analysed.
Key words: EoceneOligocene, Eastern Carpathians, Romania, Moldoviþa Lithofacies, paleogeography, petrography,
sedimentology.
Introduction and objectives
The lithostratigraphy, sedimentology and mineralogical-petro-
graphic characters of the Moldoviþa Lithofacies
1
(Tarcãu
Nappe, Eastern Carpathians) show evidence of different sedi-
mentary supplies.
This particular sedimentation, occurred in the outer flysch
of the Eastern Carpathians (Sãndulescu et al. 1995), emphasiz-
es some important paleogeographical implications. The differ-
ent petrofacies characterizing some stratigraphic intervals of
the Tarcãu Nappe, in fact, suggest a differentiated sedimentary
supply by different sources since Eocene times linked to the
different deposits belonging to the following groups of strati-
graphic successions: Tarcãu, Tazlãu and Doamna Lithofa-
cies, from west to east (see Table 1 and references therein, af-
ter Grasu et al. 1988).
This differentiated sedimentation also continued during Oli-
gocene times with the deposition of three different succes-
sions, cropping out in the northern part of Romanian Eastern
Carpathians (north of the Trotuº Fault) and known as Fusaru
and Kliwa Lithofacies and Moldoviþa Lithofacies, from
west to east, respectively (Table 1). The Moldoviþa Litho-
facies (Ionesi 1971) represents a sedimentary succession very
diversified in lithology, which continues upwards the sedi-
mentation of the underlying formations belonging to the
Tazlãu Lithofacies.
This peculiar character could be related to different prove-
nances, which must be detected in order to define a more exact
paleogeographical scenario.
Similar turbiditic successions, well characterized by differ-
ent composition and provenance (quartzarenites and lithic
arkoses up to litharenites, fed from external cratonic areas
GEOLOGICA CARPATHICA, 55, 4, BRATISLAVA, AUGUST 2004
299309
1
The lithofacies term is here adopted according to the Romanian geological literature (sensu Ionesi 1971). It re-groups together more
geological formations on the basis of their petrographic similarities and not in observance to the international stratigraphic criteria. In
this work we maintain this terminology waiting for to attain a stratigraphic revision of the Tarcãu Nappe.
300 GIGLIUTO et al.
and from inner crystalline belts with their sedimentary cover,
respectively), are known along the Betic-Maghrebian Chains
as Mixed Successions, thus testifying a system source area-
sedimentary basin strongly affected by the initial phase of the
tectogenesis (Grasso et al. 1987; Carmisciano et al. 1987).
In particular, the identification of the different provenances
characterizing both the Tazlãu and Moldoviþa Lithofacies
successions in the Carpathian Chain might provide useful pa-
leogeographical information about the EoceneOligocene
evolution of source areas and depositional systems in the East-
ern Carpathians (outer Flysch Zone Domain), so representing
a key-element for the reconstruction of the geodynamic evolu-
tion of the orogen and for regional correlations.
Thus, this paper aims (i) to provide new interdisciplinary
stratigraphic, sedimentological and petrographic data from the
Eocene-Oligocene Moldoviþa Lithofacies
2
, (ii) to detect the
paleogeographical context of this succession and (iii) to evalu-
ate the possibility of correlation of the studied deposits with
other similar Mixed Successions recognized in the Betic-
Maghrebian Chain, thus pointing out the real significance in
the framework of the geodynamic evolution of a convergent
orogenic system.
Geological setting
The Romanian Carpathians, about 700-km long fold-thrust
belt with a striking arc structure formed during the Cretaceous
and Cenozoic tectogenesis, are subdivided into inner and outer
sectors (Fig. 1).
TARCÃU NAPPE
Lower
Miocene
Vineþiºu Formation
Vineþiºu Formation
Fusaru Sandstones
Kliwa Sandstones +
Fusaru Sandstones
Kliwa Sandstones
Lower dysodilic shales
Lower dysodilic shales
Lower dysodilic shales
Brownish bituminous marls
Brownish bituminous marls
Brownish bituminous marls
Compact Menilites
Compact Menilites
Compact Menilites
Oligocene
Fu
sa
ru
Litho
fa
cies
Lo
w
er
Me
ni
lit
es
Tãrcuþa Sandstones
M
ol
dovi
þa
L
ith
of
aci
es
Lo
w
er
Me
ni
lit
es
Lingureºti Member
Kliw
a
L
itho
fa
cies
Lo
w
er
Me
ni
lit
es
Lingureºti Member
Ardeluþa Formation
Lupoaia Formation
Lucaceºti Sandstones
Podu Secu Formation
Plopu Formation
Bisericani Formation
Doamna Limestones
Eocene
Tazl
ãu
Li
th
of
aci
es
Tazlãu Formation
D
oam
na
Litho
fa
cies
Suceviþa Formation
Tarcãu Sandstones
Straja Formation
Paleocene
Izvor Formation
Tarcãu
Li
th
of
aci
es
Horgazu Formation
Hangu Formation
Cîrnu ªiclãu Formation
Cretaceous
Audia Formation
The lithofacies term is derived from the Romanian geological literature, where it is used not in observance to the international stratigraphic criteria,
but for re-grouping more geological formations with similar petrographic characters.
Table 1: CretaceousTertiary lithostratigraphic successions of the Tarcãu Nappe and their eastward lateral variations (toward right in the
scheme, after Grasu et al. 1988, modified).
2
C. Grasu and C. Miclãuº suggested the location of the studied log, D. Puglisi together with C. Grasu and C. Miclãuº are responsible for the
geological chapters and for the conclusions. Petrographic analyses have been carried out by D. Puglisi, L.G. Gigliuto and G. Raffaelli and
sedimentological data were collected by F. Loiacono, C. Miclãuº and E. Moretti.
PROVENANCE OF THE MOLDOVIÞA LITHOFACIES (EASTERN CARPATHIANS) 301
The first ones, made up by crystalline basement nappes and
by their Mesozoic sedimentary cover (Dacide Units, sensu
Dumitrescu et al. 1962), predominantly deformed during Cre-
taceous times, comprise several continental blocks (i.e. the
North Pannonian and Tisza-Dacia blocks, this last including
the Apuseni Mts and other basements of the Eastern and
Southern Carpathians; Balla 1984, 1986; Csontos 1995).
The Outer Eastern Carpathians (Moldavide nappe complex,
Sãndulescu 1975, 1980, 1984; Debelmas et al. 1980), instead,
characterized by mainly Tertiary deformations and consisting
mainly of Cretaceous to Tertiary flysch and molasse nappes,
form a continuous, curved belt, convex towards the foreland.
The Moldavide nappe complex also shows an outward struc-
tural vergence and an outward propagation of the deforma-
tions and of the facies migration through time, already recog-
nized many times by Romanian authors.
In the Eastern Carpathians, the tectonic units of these differ-
ent sectors (Internal Dacide and Moldavide Units) are separat-
ed by several tectonic units, mainly represented by the flysch
deposits belonging to the Outer Dacide Units (Ceahlãu Nappe,
Black Flysch, Baraolt and Bobu Nappes), which underwent
mainly Cretaceous deformation (Sãndulescu 1975, 1984; Sãn-
dulescu et al. 1995).
The successions of the Moldavide Units, originally deposit-
ed in the same basin of the successions of the Outer Dacide
nappe complex, represent the tectonic-sedimentary result of a
deposition on a basin floored by oceanic or strongly thinned
continental crust, affected by Late Cretaceous to Tertiary sub-
duction under the Tisza-Dacia block, preluding the collision
of this block with the European craton during Miocene times
and the consequent closure of the Carpathian flysch basin
(Rãdulescu & Sãndulescu 1973; Royden 1993).
The Moldavide nappe complex includes sediments progres-
sively younger towards structurally lower positions. Thus, the
innermost units, the Teleajen Nappe (Curbicortical Nappe or
Convolute Flysch Nappe, in the older literature), as well as the
Macla and the Audia Nappes mainly consist of Cretaceous fly-
sch, whereas the outermost ones, Tarcãu and Vrancea Nappes
(this last also known as Marginal Fold Nappe, in the older lit-
erature) together with the Pericarpathian Nappe (Folded Mo-
lasse or Inner Molasse) and with the deformed foreland, are
formed mainly by Tertiary to Recent flysch and molasses.
The foreland of the Eastern Carpathians is represented by
several platforms of different age (East European Platform,
known as Moldavian Platform on the Romania territory, and
Scythian Platform). In the Black Sea sector it includes the pe-
Fig. 1. Geological sketch map of Romania (after Dumitrescu & Sãndulescu 1968, simplified and modified). 1 East European Platform;
2 and 3 Moesian and Scythian Platforms; 4 North Dobrogea Orogen; 5 Internal Dacides; 6 Transylvanides; 7 Pienide
Units; 8 Median Dacides; 9 External Dacide Units; 10 Marginal Dacides; 11 Moldavide nappe complex; 12 Post-orogenic
covers; 13 Neogene molasse depression and foredeep; 14 Neogene magmatic arcs; 15 faults, 16 location of the study section.
302 GIGLIUTO et al.
culiar intracratonic chain of the North Dobrogea Orogen, a
folded belt made up by deformed Paleozoic crystalline rocks
and by Triassic and Jurassic sedimentary successions together
with magmatic rocks.
Nevertheless, Grasu et al. (2002) point to the existence of a
new foreland basin system located in front of the Eastern Car-
pathians, strongly controlled by the Volhynian tectonic, thus
admitting that the Romanian area of the East European Platform
did not act as a real platform because it was reactivated during
the intra Badenian (?) and intra Volhynian tectogenesis.
The Tarcãu Nappe of the Moldavide nappe complex is the
object of this study. This nappe, in fact, includes the Tazlãu
successions and the Moldoviþa Lithofacies (Eocene and Oli-
gocene in age, respectively
3
) which could be comparable, as
regards the paleotectonic implications, to those defined and
described in the Maghrebian Chain by Grasso et al. (1987) and
by Carmisciano et al. (1987). The stratigraphic succession
sampled and measured along the Ovãzu River, near the
Ciumârna village (exactly at the confluence of the Ovãzu and
Ciumârna Rivers; latitude 47°43\13\\, longitude 25°36\48\\
and altitude ~780 m a.s.l.) where the succession here de-
scribed is well exposed, could correspond to the Tazlãu-
Moldoviþa Lithofacies boundary (i.e. to the Lupoaia-Lower
Menilites boundary, Stoica 1944; Ionesi 1965; Ionesi & Grasu
1987, see Table 1).
Sedimentology of the Moldoviþa Lithofacies section
The stratigraphic section of the Moldoviþa Lithofacies,
measured in the above-mentioned locality, allows us to recog-
nize the facies characters and the vertical stacking pattern of
an up to 130 m thick succession, representing the uppermost
part of the Plopu Formation (Atanasiu 1943), the Lupoaia For-
mation, up to the Lingureºti Member and the overlying Com-
pact Menilites, both representing the so-called Lower Meni-
lites (Stoica 1944).
The section is mainly composed of thin-bedded and fine-
grained deposits, characterized by appreciable variations in
the lithological character as well as in the sandstone : mud-
stone ratio and in sedimentary structures (Fig. 2).
Four stratigraphic intervals, corresponding to depositional
elements or members of a deep sea system, are distinguished
from the base:
1. Lower shale-rich interval (029 m). In this stratigraphic
interval, almost equivalent to the uppermost part of the Plopu
Formation, the sandstone : mudstone ratio is very low (less or
much less than 1). The sandstone beds are thin or very thin (2
8 cm), rarely thicker than 10 cm. Two types of sandstones are
distinguished on the basis of their structural characteristics
and petrographic composition. The litharenitic type, fine or
very fine-grained, thinly laminated, has a transitional contact
with the overlying mudstone and is interpreted as the product
of mud-rich turbidity current (facies C
2.2
of Pickering et al.
1989). The more quartzose type, coarse-grained (1 mm) at the
base, clearly graded, laminated at the top (Bouma sequences
type Tab), split from the upper mudstone, is referred to denser
turbidity currents. The sharp contact between sandy and mud-
dy portions may be related to different mechanism or to differ-
ent source. Further analyses might reveal some mixing of the
suspended load. Waning flows may be responsible of most
deposition of silty-shale beds, thick or very thick.
2. Arenaceous interval (2970 m). This interval, equiva-
lent to the Lupoaia Formation, is characterized by (1) a sharp
contact with the underlying mudstone member, (2) a
sandstone : mudstone ratio close to 1 and (3) thicker sandstone
beds (up to 80 cm). The more common structures of these beds
are: flat lower contact, sole markings (current and load), rip-up
clasts or scattered pebbles, Bouma divisions (Tad, Tbd, Tce
sequences). At the scale of outcrops the small-medium scale
geometries of the sandstone beds refer to amalgamated bodies
through wavy surfaces, even low-angle embricated (Fig. 3a),
or with deformation structures as thick convolute divisions
(Fig. 3b). In many cases the sandstone beds have wavy or
truncated upper surfaces (small scale ripple laminations) in
transition to thinly laminated muds (Fig. 3c). The former tur-
bidite beds, in many cases made up by lithic and micaceous
sandstones, indicate depositional processes during the waning
stage of initial highly concentrated mud-rich turbidity cur-
rents; the latter, truncated ones, quartzose type, probably sug-
gest topping process (erosional effect) during by-passing of
high energy currents. These facies are related to different
types (C
2.2
, C
2.3
and C
2.4
) of C
2
group (Pickering et al. 1989).
Some thinning- or thickening-upward sequences are recog-
nized in a few meters thick packages, probably linked to auto-
cyclic processes (e.g. compensation cycles, Mutti & Sonnino
1981). An amalgamated sandstone bed, 3 m thick, shows mul-
tiple graded intervals (grain size up to 1 mm) and cross lami-
nations at the top. The recurrent tractive structures as horizon-
tal to wavy parallel laminations (Fig. 3a,b), climbing and
convolute cross laminations (Fig. 3c) suggest a by-passing
process in the transport of clastic material. The deposits of this
interval are referred to a more proximal area and higher energy
than the underlying interval.
3. Upper shale-rich interval (7092 m). This interval,
equivalent to the Lingureºti Member, is composed of thin (up
to 5 cm) sandstone beds, showing lens-shape and base cut-out
Bouma sequences (Tbe, Tce) related to facies C
2.3
of Pickering
et al. (1989). The dominant facies is represented by black
mudstones or shales. The sandstone : mudstone ratio is <1,
rarely >1. This interval shows a gradual decrease of sandy
supply and energy of the flows. The facies relationships with
the underlying interval allow us to connect these deposits with
the switching of an active depositional or feeding system (lobe
or channel).
4. Mudstone interval with siliceous beds (95127 m).
Very thin fine-grained silty beds (27 cm), interbedded to
thicker mud intervals are the main lithologies of this interval
3
Preliminary analyses on calcareous nannofossils observed in few samples suggest that the studied section is not older than Late Eocene
in age, Zone NP19 (Martini 1971), on the basis of the occurrence of Isthmolithus recurvus, and seems to extend up to the Oligocene
(Zone NP21).
PROVENANCE OF THE MOLDOVIÞA LITHOFACIES (EASTERN CARPATHIANS) 303
Fig.
2.
Sedimentological
log
of
the
Ovãzu
river
section.
304 GIGLIUTO et al.
(Fig. 3d). These sediments are devoid of primary current-
formed structures. Only the thin silty beds can show faint lam-
inations (facies D
2
of Pickering et al. 1989).
The main sedimentological characteristics are:
a. upward increase of chert with bedded cherts,
b. rhythmically interbedded thick mudstone, thin sandstones
and menilite beds,
c. the ratio between the various type of lithologies shows an
upward increase of the menilite facies and a decrease of the
sandstones.
The stratification is homogeneous: the beds are 27 cm thick.
This interval shows a drastic decrease of terrigenous supply
and a depositional area typical of open basin where the pelitic
component is dominant (facies G of Pickering et al. 1989).
An attempt at interpretation
A preliminary interpretation of the stratigraphic section re-
ferred to the Tarcãu Nappe of the Moldavide domain can be
based on sedimentary features and petrographic compositions.
A more complete reconstruction of the depositional system
could be advanced from further studies extended to the whole
Tarcãu Nappe.
Bed thickness, grain size and sedimentary structures ob-
served in the previously described intervals give some indica-
tion on the depositional mechanisms and paleoenvironments.
The lower part of the section (first interval) is composed of
stacked fine-grained facies (mudstones) and very thin, locally
well graded and coarse-grained sandstone beds, with a
sandstone : mudstone ratio <1. These characteristics suggest
dilute turbidity currents depositing in a marginal area of a tur-
bidite system (Mutti 1977) not well specifiable (lobe fringe or
outer fan?).
The second interval shows thicker and coarser sandstone
beds, in some cases amalgamated, referred to relatively more
frequent and denser turbidity currents.
The abundant erosional and tractive structures may be con-
nected with a more active approaching source area (lobe or
channel system). In fact, sole marks, scattered pebbles and rip-
up clasts are discovered in both amalgamated and medium-
thin beds.
Tractive structures (parallel, cross and wavy laminations) as
well as convolute and small slices or thin embricated beds
(Fig. 2) can indicate down-current deformation processes and
large sedimentary shear structures connected with a highly
concentrated bedload at the base of high-density turbidity cur-
Fig. 3. a A bedset type of thin amalgamated or separated beds from wavy surfaces or very thin mudstones. In the lower part irregular ge-
ometries are visible on a small scale, suggesting weak effect of shearing. In the upper part the thick bed is a bioturbated massive fine sand-
stone. b Thick amalgamated sandstone bed, internally wavy laminated and partially embricated. c Bouma sequence of C
2
facies show-
ing a thick convolute interval. An upper sharp contact with a thin small scale ripple interval and the uppermost thick laminated mudstone bed
reveals the surge character of tractive and traction plus fallout process. d Facies characteristics of the uppermost interval of the studied
section. In the middle part of the photo two well cemented beds are visible interbedded to thick marls: the lower one is a siliceous bed (meni-
lite facies), the upper one is a quartzose sandstone passing upward to emipelagic mudstones (facies G).
PROVENANCE OF THE MOLDOVIÞA LITHOFACIES (EASTERN CARPATHIANS) 305
rents. The range of the structures observed in the beds of this
interval of the Moldoviþa Lithofacies section may be rela-
tively common in the process of flow transformation associat-
ed to high-density turbidity currents, as shown in the classifi-
cation scheme of turbidite facies by Mutti (1992) and observed
in the Grès dAnnot (Clark & Stanbrook 2001). In a prelimi-
nary interpretation, the depositional area of these turbidites
may be related to the peripheral zone of a depositional lobe or
a channel-levee system.
The third and fourth interval may indicate the recessional
trend of a turbidite system and the evolution to a basin plain
system characterized by an ever decreasing terrigenous input
and consequent increase in pelagic deposition.
Petrographic characteristics of the sandstones of the
Moldoviþa Lithofacies
Modal point counting in thin section (Table 2) has been car-
ried out in order to detect the composition, the petrographic
characters and the main textural features of the sandstones of
the Moldoviþa Lithofacies. The gross composition has also
been checked by means of qualitative mineral phase analyses
obtained with diffractometric methodologies (Table 3).
Table 2 lists the gross composition of the sandstones charac-
terizing the Moldoviþa Lithofacies. The samples have main-
ly been collected from the first three stratigraphic intervals ex-
cluding the fourth one because of the abundance of menilite
facies in spite of the sandstone levels.
Nevertheless, some samples of the menilite facies observed
in thin section show abundant dull-greyish to brownish variet-
ies of opal as well as, locally, cryptocrystalline and fibrous va-
rieties of quartz as chert and chalcedony, respectively. Other
samples of this menilite facies appear to be almost completely
formed by chert, made up by cryptocrystalline to, rarely, fine-
grained microcrystalline aggregate of quartz. Finally, other
rocks of this facies (sample ROM 29), consisting of a mixture
of clay or silty clay and a large but variable proportion of opa-
line silica, show a finely laminated structure and an abnormal-
ly high content in quartz and could be related to the family of
the siliceous shales (sensu Pettijhon 1975).
The mean values of the detrital modes known in literature
for the Fusaru and Kliwa Sandstones (Vinogradov et al. 1983;
Grasu et al. 1988), which can be related to the analysed rocks,
are shown in Table 2 and/or in Fig. 4, where they are com-
pared with the new petrographic data here obtained for the
Moldoviþa Lithofacies terrigenous arenites. Table 2 also
gives the compositional parameters adopted for the modal
analysis; these have been performed according to the criteria
suggested by Gazzi (1966), Dickinson (1970) and by Gazzi et
al. (1973), in order to minimize the dependence of the rock
composition on grain size. The Q
m
, F and L
t
parameters are
also included in this Table, as suggested by Graham et al.
(1976) and by Dickinson & Suczek (1979) as a means of rec-
ognizing the provenance of the clastic supply (QFL and Q
m
FL
t
parameters, in fact, emphasize maturity and provenance of the
sandstones, respectively).
The analysed rocks can be referred to the quartzarenite/sub-
litharenite and to the litharenite/feldspatic litharenite groups
(sensu Folk 1974). In the first case (samples ROM 1, ROM 2,
ROM 8, ROM 10, ROM 12, ROM 15, Fig. 5a and 5b) the
rocks show very high compositional maturity (Q
91.8
F
3.7
L
4.5
,
Qm
51.7
F
3.7
Lt
44.6
) coupled with a poor sorting and with a mod-
erate to high roundness of the detrital quartz grains. Other
mineralogical components are rare; however, a few well
rounded grains of K-feldspar and plagioclase occur in these
rocks as well as smaller amounts of fine-grained rock frag-
ments (mainly epimetamorphic clasts), together with moderate
amounts of glauconite (max. 12.0 %), nearly always present,
and with very low contents of micas and/or chlorites.
In contrast, the litharenite/feldspatic litharenite rocks
(Q
58.9
F
6.5
L
34.6
, Qm
39.9
F
6.5
Lt
53.6
, samples ROM 9, ROM 13,
ROM 14, ROM 18, ROM 23, ROM 27, Fig. 5c and 5d) are
characterized by the prevalence of quartz grains and of lithic
fragments, with a very low content of feldspars. The lithic
fraction is mainly represented by carbonate rocks, fossils,
epimetamorphic lithic clasts as phyllites and rare quartzites
and few sedimentary rocks (quartzose siltstones, shales and
rare metarenites). These sandstones usually show a low textur-
al maturity (poor sorting, abundance of angular to subangular
quartz grains, locally presence of a small amount of siliciclas-
tic matrix, often pseudomatrix-like, sensu Dickinson 1970),
which strongly points to very short transports.
The Quartz-Feldspars-Lithic Fragments ternary plot (Fig. 4)
shows the gross composition of the Moldoviþa Lithofacies
sandstones together with the bulk of the compositional data of
the Fusaru and Kliwa Sandstones (Vinogradov et al. 1983),
probably corresponding respectively to the litharenite and
quartzarenite sandstones analysed.
Quartz is by far the most abundant mineral in both the sand-
stone families recognized. The great variability of textures dis-
played suggested the possibility of collecting further petro-
graphic data during the point-counting of the modal analyses,
useful for detect the provenance of the sandstones. So, accord-
Fig. 4. Quartz-Feldspars-Lithic Fragments ternary plot showing
the composition of the analysed sandstones (Moldoviþa Lithofa-
cies), compared with the Kliwa and Fusaru Sandstone Formations.
306 GIGLIUTO et al.
ing to the Basus (1985) criteria, modified by Basu et al.
(1975), two different types of detrital quartz have been distin-
guished: monocrystalline and polycrystalline quartz grains.
Each of these has been subdivided into two populations: the
monocrystalline quartz grains have been separated into variet-
ies of low and high undulosity (i.e. ≤5° or >5° apparent angle
of extinction, determined using a flat-stage) and the polycrys-
Table 2: Modal point counts of the Moldoviþa Lithofacies sandstones compared with the Kliwa Formation.
Symbols of the parameters adopted for the modal analysis
Q = Q
m
+ Q
p
, where: Q = total quartzose grains including Q
m
= monocrystalline quartzose grains subdivided into Q
m
= of low undulosity (< 5°)
and Q
m
= of high undulosity (> 5°) and Q
r
= quartz in coarse-grained rock fragments (i.e. > 0.06 mm), Q
p
= polycrystalline quartzose
grains (including Ch = chert) subdivided into Q
p
= with few subgrains (= 4 crystalline units per grain) and Q
p
= with many subgrains (> 4
crystalline units per grain);
F = P + K, where: F = total feldspar grains, P and K = plagioclase and potassium feldspar single grains (Ps and Ks) or in coarse-grained rock
fragments (Pr and Kr);
L = Lv + Lc + Lm, where: L = unstable fine-grained rock fragments (< 0.06 mm, including: Lv = volcanic, Ls = sedimentary, Lc = carbonate,
Lm = epimetamorphic lithic fragments and Fo = fossils);
Lt = L + Q
p
, where: Lt = total lithic fragments (both unstable and quartzose);
M = micas and/or chlorites, in single grains (Ms) or in coarse-grained rock fragments (Mr);
Gl = glauconite grains, Al = other mineral grains, Mt = siliciclastic matrix; Cm = carbonate cement. Sp = sporadic occurrence.
talline quartz grains have been subdivided by the number of
crystal units contained within each grain (with few or many
subgrains, ≤4 or >4).
The data concerning the undulatory extinction and the poly-
crystallinity of the detrital quartz grains should be collected
only from the medium sand-size fraction (0.20.5 mm) be-
cause of the well known relationship between grain size and
ROM
1
ROM
2
ROM
8
ROM
9
ROM
10
ROM
12
ROM
13
ROM
14
ROM
15
ROM
18
ROM
23
ROM
27
x
ó
x
ó
Kliwa Sandstones*
Q
m
10.3 9.9 9.5 8.1 7.8 16.5 15.5 5.2 7.1 8.3 9.8 10.6 10.3 3.04 9.6 3.14
Q
m
27.7 22.9 25.9 13.6 25.1 40.2 27.6 22.4 37.9 15.2 16.6 28.1 30.0 6.62 20.5 5.81
Q
p
7.0 8.5 11.9 2.6 20.6 11.8 6.4 3.3 12.6 4.9 5.5 6.5 12.1 4.31 4.9 1.47
Q
p
10.7 14.8 24.9 3.2 25.9 17.3 10.1 9.8 21.6 11.5 9.6 10.1 19.3 5.45 9.1 2.69
Qr
0.8 0.5
0.8
0.1 0.30 0.2 0.32
Ch
1.1 3.5
0.4 0.3
3.6 2.6 0.7 0.8 1.29 1.3 1.34
Q 8090
Ps
2.7 2.7 1.1 1.4 1.6 0.5 1.1 2.1 1.7 5.7 3.3 5.2 1.7 0.80 3.1 1.78
Pr
0.3
0.5
0.8 0.1 0.11 0.2 0.32
Ks
2.1 0.9 1.4 1.1 0.8 0.7 0.9 1.2 1.4 4.1 1.3 1.0 1.2 0.48 1.6 1.12
Kr
0.5
0.2
0.1 0.19
F 510
Lv
1.3 1.2
0.4
1.6 5.2 5.1 0.4 0.59 2.1 2.26
Lc
1.5 1.9
23.1
6.8 10.8 0.8 5.3 1.1
0.7 0.77 7.9 7.70
Ls
1.7 2.4
2.2
1.1 1.07
Lm
1.8 1.2 1.8 3.2 1.2 0.4 7.9 9.4 0.8 15.1 11.6 10.8 1.2 0.50 9.6 3.64
Fo
0.8 1.7
17.1
5.7 10.5 5.3 0.9 7.0
1.3 1.89 6.9 5.80
L
Ms
6.7 9.2 6.9 8.4 6.5 2.2 4.2 7.8 2.9 6.3 6.2 5.5 5.8 2.43 6.4 1.39 Gl 310
Mr
0.8 1.7
1.6 1.1
0.9 0.68
Gl
11.3 12.0 8.2 2.2 6.1 3.3 0.2 0.3 3.6
7.2 5.2 7.5 3.41 2.5 2.76
Op
0.9
1.1
2.0 0.9 1.8
0.3 0.42 0.8 0.86
Al
1.1
0.6
1.6 0.4
1.2
0.6 0.58 0.2 0.45
M + Al sp
Mt
8.9 5.7 5.1 3.4 0.7 4.4 3.1 1.6 2.7 2.5 1.3 8.2 3.2 1.96 3.3 2.29
Cm
4.1 3.9 1.6 9.9 2.1 2.3 6.4 9.2 0.7 9.9 10.6
2.4 1.21 7.7 3.68
100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
100.0
* Mean framework
modes from Grasu
et al. (1988).
Q
84.7 86.2 94.2 38.1 95.7 98.1 71.1 58.8 88.8 56.7 59.9 69.1 91.8 4.99 58.9 10.73
F
7.2 5.2 3.6 4.0 2.9 1.4 2.6 3.7 3.5 13.4 6.3 8.6 3.7 1.83 6.5 3.68
L
8.1 8.6 2.2 57.9 1.4 0.5 26.3 37.5 7.7 29.9 33.8 22.3 4.5 3.32 34.6 11.50
100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
100.0
x and ó = average
and standard
deviation of
quartzarenites.
Q
m
50.7 47.4 46.8 30.4 39.7 64.7 51.2 43.6 50.4 30.7 35.8 47.7 51.7 7.52 39.9 5.54
F
7.2 5.2 3.6 4.0 2.9 1.4 2.6 3.7 3.5 13.4 6.3 8.6 3.7 1.83 6.5 3.68
L
t
36.1 47.4 49.6 65.6 57.4 33.9 46.2 52.7 46.1 55.9 57.9 43.7 44.6 8.00 53.6 7.32
100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
100.0
x and ó = average
and standard
deviation of
litharenites.
PROVENANCE OF THE MOLDOVIÞA LITHOFACIES (EASTERN CARPATHIANS) 307
Table 3: Main mineral phases recognized by X-ray diffraction in
the analysed sandstones.
Fig. 5. a Quartzarenite (sample ROM 12) showing a big lithic fragment with schistose texture (N :); b Very poorly sorted quartza-
renite (sample ROM 10) with well rounded detrital quartz grains (N 11); c Litharenite (sample ROM 9) showing abundant micritic
limestone and fossil fragments (N 11); d Subangular quartz grains, micas, carbonate rock fragments and fossils within a litharenite
sample (ROM 14; N :).
Sample
Qz
Pl
Kf I/M Chl Ca Do Py
S
ROM 1
XXXX X
±
±
tr
±
ROM 2
XXXX X
±
±
±
±
ROM 8
XXXX ±
±
±
±
±
tr
tr
±
ROM 9
XX
±
tr
±
tr XXX tr
ROM 10
XXXX ±
±
±
±
±
tr
ROM 12
XXXX ±
±
tr
±
±
tr
ROM 13
XXX
±
±
±
±
X
tr
ROM 14
XXX
±
±
X
±
X
tr
±
ROM 15
XXXX ±
±
tr
±
tr
ROM 18
XXX
±
tr
±
±
±
X
±
ROM 20
XXX
X
±
X
±
±
±
±
tr
ROM 23
XXX
±
tr
±
tr
X
X
±
ROM 27
XXXX X
X
±
±
tr
tr
±
Abbreviations and symbols: Qz Quartz, Pl Plagioclase, Kf K-
feldspar, I/M Illite/Mica Group, Chl Chlorite, Ca Calcite, Do
Dolomite, Py Pyrite, S Sulphates; XXXX very abundant, XXX
abundant, XX less abundant, X discrete, ± minor, tr trace.
4
Small amounts of very alterated volcanic rocks, mainly represented by fragments of oligohyaline fine-grained groundmass, are also present.
amount of polycrystalline and undulatory quartz (Connolly
1965; Basu et al. 1975; Young 1976). These varieties of
quartz, in fact, strongly point to selective destruction by me-
chanical agencies during prolonged transports as well as dur-
ing successive sedimentary cycles (Blatt & Christie 1963;
Basu 1985). Thus, as the results of the modal analyses of this
study regard all the possible grain sizes of the quartz grains
present within the sandstones and occurred during the point-
counting and since the analysed sandstones are usually medi-
um- to fine-grained, we can quite suppose that the above men-
tioned criteria have been respected.
In both the recognized clans of sandstones it is important to
underline that the monocrystalline quartz grains with high un-
dulosity and polycrystalline grains with many crystal units per
grain are more abundant than the varieties with low undulosity
and with few subgrains, thus suggesting a predominant prove-
nance from low grade metamorphic sources.
This result is well supported for the litharenite/feldspatic
litharenite sandstones by the occurrence of abundant fine-
grained lithic fragments of semischists, chlorite-schists,
quartzites, locally mixed with micritic limestone and abundant
fossils
4
. In addition, the scarce content of feldspars in spite of
the abundance of quartz and lithic fragments excludes a con-
spicuous contribution from plutonic and/or high grade meta-
morphic sources.
In contrast, the provenance of the quartzarenites is more dif-
ficult to hypothesize. In fact, the occurrence of very few
epimetamorphic rock fragments is not sufficient to justify a
sediment supply from low grade metamorphic rocks as sug-
gested by the study of the polycrystallinity and undulatory ex-
308 GIGLIUTO et al.
tinction of the detrital quartz grains. Furthermore, the high
compositional maturity together with the moderate to high
roundness of the quartz grains seems to suggest prolonged
transports of the detritus or, more probably, a polycyclic ori-
gin, as strongly emphasized by Suttner et al. (1981) for the
bulk of ancient quartzarenites. In this case, the abundance of
polycrystalline and undulatory quartz grains could acquire an
important significance; in fact, taking into account the lower
stability of these varieties of quartz and assuming these rocks
as affected by more sedimentary cycles, we would quite sup-
pose the sediment sources must have been enriched in these
types of quartz and thus they may have been represented also
by low grade metamorphic rocks.
Thus, the difference from the other type of sandstone with
litharenite/feldspatic litharenite composition does not consist
only of a larger amount of fine-grained rock fragments charac-
terizing these last rocks (carbonate, epimetamorphic lithic
fragments and, locally, abundant fossils), but it is also related
to different modalities of sedimentary transport as well as to a
different geological history including different sources, to-
gether, probably, with a polycyclicity of the detritus responsi-
ble for the enrichment of quartz.
Conclusions
The results of this paper concerning the study of a strati-
graphic interval, not more than 130 m thick and located at the
boundary between the Tazlãu and the Moldoviþa Lithofacies
successions (Late EoceneEarly Oligocene), mark the evi-
dence of a turbiditic deposition, related to the peripheral zone
of a depositional lobe or a channel-levee system and linked to
different sedimentary supplies.
The vertical evolution of the analysed stratigraphic succes-
sion may indicate a recessional trend of the turbidite system
evolving to a basin plain system (interval four, menilite facies
with siliceous shales), with decrease in the terrigenous input
and consequent increase in pelitic deposition. The other strati-
graphic intervals, instead, are always characterized by turbid-
ite sandstones strongly different in composition.
Mainly quartzarenite and litharenite compositions, in fact,
characterize these sandstones suggesting the existence of two
different provenances, testified by the presence of abundant
detrital quartz grains with moderate to high roundness in the
first type, and of abundant lithic fragments (carbonate rocks,
quartzose siltstones, shales and epimetamorphic lithic clasts)
together with moderate contents of angular to subangular
quartz grains in the second type. These provenances must be
related to different sediment sources, which could be tenta-
tively identified with external cratonic areas in the first case
and with inner crystalline belts together with their sedimentary
cover in the second.
This particular interference of two opposite depositional
systems has already been observed in different sectors of the
Betic-Maghrebian Chain (Oligocene-Miocene Mixed Suc-
cessions, sensu Grasso et al. 1987; Carmisciano et al. 1987)
with the significance of a sedimentation related to the begin-
ning of the tectogenesis, aged to Upper OligoceneLower Mi-
ocene, antecedent to the Maghrebian Flysch Basin closure.
The older age of the study succession (EoceneOligocene)
can quite exclude the previous tectonic interpretation because
the deposition of the Moldoviþa Lithofacies is continuous up
to the Oligocene-Miocene boundary. Thus, we suppose that
only peculiar paleogeographical scenarios with not very large
basins, where interference between two different depositional
systems with different provenance was possible, could permit
the deposition of the analysed succession.
Acknowledgments: Financial support was provided by the
Italian MURST as grants to D. Puglisi and as Cofin 2002
(U.R.F. Lentini, University of Catania). We thank M. Sãndu-
lescu (University of Bucharest), Z. Kukal (Czech Geological
Survey, Prague) and an anonymous referee for their careful re-
vision of the manuscript. We also thank Patrizia Maiorano
(University of Bari) for the preliminary micropaleontological
analyses.
References
Atanasiu I. 1943: Les faciès du Flysch marginal dans la partie moy-
enne des Carpathes moldaves. An. Inst. Geol. Romania XXII,
146176.
Balla Z. 1984: The Carpathian loop and the Pannonian Basin: a ki-
nematic analysis. Geophys. Trans. 30, 313353.
Balla Z. 1986: Paleotectonic reconstruction of the central Alpine
Mediterranean belt for the Neogene. Tectonophysics 127,
213243.
Basu A. 1985: Reading provenance from detrital quartz. In: Zuffa
G.G. (Ed.): Provenance of arenites. Reidel, Dordrecht, 231247.
Basu A., Young S.W., Suttner L.J., James W.C. & Mack G.K. 1975:
Re-evaluation of the use of undulatory extinction and polycrys-
tallinity in detrital quartz for provenance interpretation. J. Sed.
Petrology 45, 873882.
Blatt H. & Christie J.M. 1963: Undulatory extinction in quartz of ig-
neous and metamorphic rocks and its significance in prove-
nance studies of sedimentary rocks. J. Sed. Petrology 33,
559579.
Burchfiel B.C. & Bleahu M.D. 1976: Geology of Romania. Geol.
Soc. Amer. Spec. Pap. 158, 182.
Carmisciano R., Coccioni R., Corradini D., DAlessandro A., Guer-
rera F., Loiacono F., Moretti E., Puglisi D. & Sabato L. 1987:
New data from the Early Miocene mixed successions of Al-
geria (Great Kabylia) and of Sicily (Nebrodi Mts.): comparison
with similar Turbiditic successions of the Gibraltar Arc and of
the lucanian Apennine. Mem. Soc. Geol. Ital. 38, 551576 (in
Italian).
Clark J.D. & Stanbrook D.A. 2001: Formation of large-scale shear
structures during deposition from high-density turbidity cur-
rents, Grès dAnnot Formation, south-east France. In: McCaf-
frey W.D., Kneller B.C. & Peakall J. (Eds.): Particulate gravity
current. Spec. Publ. Int. Assoc. Sediment. 31, 219232.
Connolly J.R. 1965: The occurrence of polycrystallinity and undula-
tory extinction on quartz in sandstones. J. Sed. Petrology, 35,
116135.
Csontos L. 1995: Tertiary tectonic evolution of the Intra-Carpathian
area: a review. Acta Vulcanol. 7 2, 113.
Debelmas J., Oberhauser R., Sãndulescu M. & Trumpy R. 1980:
Larc alpino-carpathique (Colloque C5: Geologie des châines
alpines issues de la Tethys-Thème 2, 26e Congr. Géol. Inter.,
Paris). Mém. Bur. Rech. Géol. Min. 115, 8696.
Dickinson W.R. 1970: Interpreting detrital modes of graywacke and
arkose. J. Sed. Petrology 40 2, 695707.
PROVENANCE OF THE MOLDOVIÞA LITHOFACIES (EASTERN CARPATHIANS) 309
Dickinson W.R. & Suczek C.A. 1979: Plate tectonics and sandstone
composition. Amer. Assoc. Petrol. Geol. Bull. 63, 21642192.
Dumitrescu I. & Sãndulescu M. 1968: Problèmes structuraux fonda-
mentaux des Carpathes roumaines et de leur avant-pays. An.
Com. Geol. Rom. XXXVI, 195218.
Dumitrescu I., Sãndulescu M., Lãzãrescu V., Mirãuþã O., Pauliuc S.
& Georgescu C. 1962: Mémoire à la carte tectonique de la Rou-
manie. An. Com. Geol. Romania XXXIII, 596.
Folk R.L. 1974: Petrology of sedimentary rocks. Hemphills, Austin,
Texas, 1182.
Gazzi P. 1966: The upper Cretaceous flysch sandstones of the north-
ern Apennines (Modena) and their comparison with the Mong-
hidoro Flysch. Mineral. Petrogr. Acta (Bologna) 12, 6997 (in
Italian).
Gazzi P., Zuffa G.G., Gandolfi G. & Paganelli L. 1973: Provenance
and dispersal of the Adriatic beach sands between the Isonzo
and Foglia rivers: regional framework. Mem. Soc. Geol. Ital.
12, 137 (in Italian).
Graham S.A., Ingersoll R.V. & Dickinson W.R. 1976: Common
provenance for lithic grains in Carboniferous sandstone from
the Ouachita Mountains and Black Warrior Basin. J. Sed. Pe-
trology 46, 620632.
Grasso M., Guerrera F., Loiacono F., Puglisi D., Romeo M., Balen-
zano F., Carmisciano R., Di Pierro M., Gonzàles-Donoso J.M.
& Martín-Algarra A. 1987: Sedimentological, biostratigraphic
and mineralogical-petrographic characterization of Early Mi-
ocene mixed successions cropping out in Spain (Betic Chain)
and in southern Italy (Nebrodi Mts. and lucanian Apennine).
Boll. Soc. Geol. Ital. 106, 475516 (in Italian).
Grasu C., Catanã C. & Grinea D. 1988: Carpathian flysch: petro-
graphic and economic remarks. Editura Tehnicã, Bucureºti, 1
208 (in Romanian).
Grasu C., Miclãuº C., Brânzilã M. & Boboº I. 2002: Sarmatian from
the foreland basin system of the Eastern Carpathians. Editura
Tehnicã, Bucureºti, 1407 (in Romanian).
Ionesi L. 1965: The Paleogene flysch between Boului Valley and
Seaca Valley. An. ªtiinþ. Univ. Al. I. Cuza Iaºi, N. S. Secþ. II,
Geol.-Geogr. XI, 5372 (in Romanian).
Ionesi L. 1971: The Paleogene flysch from drainage basin of the
Moldova River. Editura Academiei Române, Bucureºti, 1250
(in Romanian).
Ionesi L. & Grasu C. 1987: Lithostratigraphic remarks on the
Eocene-Oligocene boundary within the Tarcãu-Fusaru lithofa-
cies. Stud. Cerc. Geol. Geofiz. Geogr., Ser. Geol. (Bucureºti)
32, 8498 (in Romanian).
Mutti E. 1977: Distinctive thin-bedded turbidite facies and related
depositional environments in the Eocene Hecho Group (South-
central Pyrenees, Spain). Sedimentology 24, 107131.
Mutti E. 1992: Turbidite sandstones. Agip S.p.A, MilanoIstituto di
Geologia, Università di Parma, 1275.
Mutti E. & Sonnino M. 1981: Compensation cycles: a diagnostic
feature of turbidite sandstone lobes. Abstract, IAS 2
nd
Eur. Mtg,
Bologna, 1981, 120123.
Pettijohn E.J. 1975: Sedimentary rocks. Harper International Edi-
tion, Harper & Row, Publishers, Inc., New York, 1628.
Pickering K.T., Hiscott R.N. & Hein F.J. 1989: Deep-marine envi-
ronments: Clastic sedimentation and tectonics. Unwin Hyman,
London, 1352.
Rãdulescu D.P. & Sãndulescu M. 1973: The plate-tectonics concept
and the geological structure of the Carpathians. Tectonophysics
16, 34, 155161.
Royden L.H. 1993: Evolution of retreating subduction boundaries
formed during continental collision. Tectonics 12, 629638.
Sãndulescu M. 1975: Essai de synthèse structurale des Carpathes.
Bull. Soc. Géol. France XVII, 3, 299358.
Sãndulescu M. 1980: Analyse géotectonique des châines alpines
situées autour de la mer Noir occidentale. An. Inst. Geol.
Geofiz. Romania LVI, 554.
Sãndulescu M. 1984: Geotectonics of Romania. Editura Tehnicã,
Bucharest, 1336 (in Romanian).
Sãndulescu M., Mãrunþeanu M. & Popescu G. 1995: General out-
look on the East Carpathians structure. In: Guide to excursion
B1 (Post-congress)/Lower-Middle Miocene formations in the
folded area of the East Carpathians. X
th
RCMNS Congress,
Bucureºti (România), 1995.
Stoica C. 1944: Paleogene from the Sibiciu Valley (Buzãu District).
Rev. Muz. Geol.-Mineral. Univ. Cluj-Napoca VIII, 1, 6485 (in
Romanian).
Suttner L.J., Basu A. & Mack G.H. 1981: Climate and the origin of
quartz arenites. J. Sed. Petrology 51, 4, 12351246.
Vinogradov C., Pârvu G., Bomboe P. & Negoiþã V. 1983: Applied
petrology of detrital rocks. Editura Academiei Române,
Bucureºti, 1327 (in Romanian).
Young S.W. 1976: Petrographic textures of detrital polycrystalline
quartz as an aid to interpreting crystalline source rocks. J. Sed.
Petrology 46, 595603.