GeolCarp_Vol56_No6_517

GEOLOGICA CARPATHICA, DECEMBER 2005, 56, 6, 517—530

www.geologicacarpathica.sk

Stratigraphy and provenance of Lower and Middle Miocene

strata within the External Tanger Unit (Intra-Rif sub-

Domain, External Domain; Rif, Morocco): first evidence

MOHAMED NAJIB ZAGHLOUL

, ANGELIDA DI STASO

LISA GIOCONDA GIGLIUTO

ROSANNA MANISCALCO

and DIEGO PUGLISI

1* Corresponding author:

Département des Sciences de la Terre, Université AbdelMalek Essaadi Faculté des Sciences et Techniques,

B.P. 416 Tanger, Maroc; Phone: +212.39393954, Fax: +212.39393953; zaghloul@fstt.ac.ma; zaghloul@geologist.com

Dipartimento di Scienze della Terra (University Federico II, Napoli), Largo San Marcellino 10, 80138 Napoli, Italy; distaso@unina.it

Dipartimento di Scienze Geologiche, University of Catania, Corso Italia 55, 95129 Catania, Italy; geolisa@infinito.it;

maniscal@unict.it; dpuglisi@unict.it

(Manuscript received July 15, 2004; accepted in revised form June 16, 2005)

Abstract: New biostratigraphic, petrographic and sedimentological investigations on Saf Lahmame marly-arena-
ceous succession of the External Tanger Unit (Intra-Rif sub-Domain, External Domain) indicate an age not older
than Burdigalian—Serravallian. The medium- to fine-grained sandstones of the Saf Lahmame succession show
mainly graded and massive amalgamated beds organized in thinning- and fining-upward sequences. Medium-
grained deposits reflect a continual process of aggradation beneath a high-density turbidity current and by a very
quick deposition for freezing of a dense cohesionless suspension under a highly concentrated flow. A fine-grained
facies association reflects slow accumulation of mud and biogenic materials and diluted and low concentration
turbidity currents. The sandstones of the sublitharenite / quartzarenite groups are characterized by common occur-
rence of glauconite grains. Their provenance seems to be exclusively related to the African Craton, which is in good
agreement with the published data on the composition of the Numidian and Numidian-like sequences in the Rif,
Betic and Apenninic-Maghrebian Chains. The SE and NW paleoflows within these sandstones could reflect a
multisource alimentation from instable marginal areas of the Africa.

Key words: Lower—Middle Miocene, Morocco, Rif Chain, provenance, nannoplankton, planktonic foraminifers,
sandstones, turbidite.

Introduction

The Rif is located at the western ending of the Maghrebi-
an Chain and, together with the Betics, forms the main Al-
pine orocline of the western and central Mediterranean
Sea. The Maghrebian Chain consists of Rif, Tell and Sicil-
ian orogenic domains (Durand-Delga 1980; Durand-Delga
& Fontboté 1980; Fig. 1a). Betic and Maghrebian Chains
namely, Internal Domains of Rif (Morocco), Kabylies (Al-
geria), Peloritani and Calabria (Italy) are derived from the
collision and break-up, since the Early Miocene, of a con-
tinental microplate initially located between Europe and
Africa, this latter is known as “Mesomediterranean Ter-
rane” or “AlKaPeCa” block (Al – Alboran, southern
Spain and northern Morocco, Ka – Kabylia, Algeria,
PeCa – Calabria-Peloritani Arc) (sensu Guerrera et al.
1993 and Michard et al. 2002, respectively).

The Mesozoic-Cenozoic terrains cropping out through

the Maghrebian Chain are related to three main paleogeo-
graphical realms: Internal Domain, Flysch Domain (Mau-
retanian Flysch, Massylian Flysch, Numidian sequence
and Mixed Successions, sensu Carmisciano et al. 1987
and Guerrera et al. 1987, 1992) and External Domain. The
latter displays a Triassic-Tertiary sedimentary succession,

originated from the African paleomargin. Since the Early
Miocene this margin has been progressively involved in
foreland basins (Guerrera et al. 1993), with several deposi-
tional systems through the whole Maghrebian Chain, con-
sisting of turbiditic successions such as the well known
Numidian Flysch and Numidian-like sequences, namely
holoquartzose turbidites and marly-clayey successions
(Durand-Delga et al. 1960—1962).

The Upper Oligocene-Middle Miocene successions of

the External Domain of the Rif, all supplied by the erosion
of the African Craton, have been considered as Numidian-
like sequences. These are the Asilah Sandstones (Critelli
1985; Cazzola & Critelli 1986—87) and the Larache Sand-
stones (Didon & Hoyez 1978), belonging to the Habt
Nappe (sensu Suter & Fiechter 1966) and to the Ouezzane
Nappe (sensu Wildi 1983), respectively. All these units,
regrouped within the Upper Intra-Rif nappes (sensu Leb-
lanc 1979) and mainly formed by Middle Miocene succes-
sions, are considerably widespread in the External Rif
Domain, probably representing the transition between the
Intra- and Meso-Rif sub-Domains. They are completely de-
tached from their Cretaceous substratum and transported far
away to the SW (Hottinger & Sutter 1961; Durand-Delga
1972; Lespinasse 1975; Benyaich 1991; Frizon de Lamotte

519

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

Fig. 1.   (Caption contiued)   Tanger Unit (Intra-Rif sub-Domain): 1 – marls and marly limestones with “yellowish nodules” and clay facies
(Campanian—Maastrichtian), 2  – clay facies (Campanian—Maastrichtian),  3  – marls with black flint (Suessonian facies) (Lower Paleocene—
Upper Eocene), 4 – marls with thin-bedded turbiditic sandstones (Middle Eocene—Oligocene), 5 – marls with thick-bedded turbiditic sandstones
(Burdigalian—Serravallian). Numidian Sequence: 6a – Brown mudrocks to rare Tubotomaculum, 6b – Variegated Clays with Tubotomaculum
(Upper Oligocene), 7  – Numidian Flysch (Aquitanian), 8  – marls and sandstones with “countourites” facies (Burdigalian). Quaternary to
Recent deposits (fluvial terraces and continental alluvial aprons): 9 – Lower Quaternary to Recent deposits (Salétien to Soltanien), 10 – Rharbian
and present deposits. Conventional symbols: 11 – geological trace, 12 – track, 13 – hydrographic network, 14 – main road, 15 – height spot,
16 – railroad, 17 – strike-slip fault, 18 – thrust, 19 – back-thrust, 20 – location of the stratigraphic section, 21 – location of the cross-section.

et al. 1991; Tejera de Leon 1993; Chalouan et al. 2001; Za-
kir & Chalouan 2003; Zakir 2004).

The Intra-Rif nappes display a simple internal structure

characterized by open folds and, locally, by a pre-nappe
cleavage (Leblanc 1979). They overthrust the Meso-Rif
and Pre-Rif sub-Domains, and they are tectonically over-
lain by the Numidian Nappe (Fig. 1b).

The Intra-Rif sub-Domain and, in particular, the Tanger

Unit, are affected by complex tectonic structures, due to
the superposition of longitudinal and transversal compres-
sive deformations of Miocene age, characterized by dis-
harmonic folds and double verging folds with rough
cleavage (El Mrihi 1995). These compressive structures
are then overprinted by a generalized release as recorded
by the widespread radial extension occurring during Late
Miocene—Early Pliocene times (Saji 1993; Chaouni 1996).

This paper aims to propose the first multidisciplinary in-

vestigation on Lower and Middle Miocene siliciclastic sed-
iments occurring within the undetached Tertiary succession
of the External Tanger Unit (Durand-Delga et al. 1985). We
emphasize for the first time the provenance and provide the
exhaustive biostratigraphy of this succession by means of
foraminifers and nannoplankton assemblages and, also, a
new sedimentological characterization of the Neogene si-
liciclastic deposits of the External Tanger Unit. This multi-
disciplinary approach will provide some answer keys that
lead to a preliminary paleogeographical scenario of the ex-
ternal portion of the Rif Chain during the Neogene.

Stratigraphy of the Tanger Unit

The Tanger Unit represents the tectonic substratum of

the flysch nappes, cropping out SE of Chefchaouen town
in a disharmonic structure (Lespinasse 1975). The Tanger
Unit tectonically overlies the Ketama Unit, which is main-
ly characterized by several kilometers thick Albian-Aptian
black flysch sequence (“schisto-gréseux” flysch of the
French Authors, Andrieux 1971).

The Tanger Unit has been subdivided into two lithos-

tratigraphic successions (Durand-Delga et al. 1960—1962;
Lespinasse 1975), deposited in different paleogeographi-
cal sectors of the basin: the Internal Tanger Unit (W of Té-
touan), bordering the “Dorsale Calcaire”, and the External
one, which shows a wide distribution of Paleogene to
Middle Miocene strata.

– The Internal Tanger Unit is characterized by a Creta-

ceous succession showing at the base Cenomanian greenish
shales (locally purplish-blue), grading upward to a siliceous
shale key-bed. The carbonate content increases upwards,

where the succession is characterized by meter-sized beds of
limestone and cherty limestone, interbedded with black sili-
ceous shales. At the top, Upper Senonian grey marls and
medium-bedded microbreccias occur (Didon et al. 1973).

– The External Tanger Unit is formed by an Upper Cre-

taceous-Neogene succession. The lower part of this succes-
sion is represented by thick Middle-Upper Senonian grey or
blackish marls with abundant nodules of limestones. They
are overlain by Campanian-Maastrichtian marls and graded
limestones; this succession lies onto Lower Senonian shales
and Cenomanian clayey limestones (Durand-Delga et al.
1985). Medium-bedded microbreccias occur at the top of
the succession, locally together with pebbles, blocks, and
sometimes sedimentary klippen of Orbitolina limestones of
a middle Cretaceous age (Didon et al. 1973).

The Paleogene and Neogene deposits of the External

Tanger Unit, cropping out to the SSW of Tangier, near Oued
Marhar (Geological map of Tanger-Al Manzla 1:50,000;
Figs. 1c, 2), lie directly above the Campanian-Maastrichtian
marls with “yellowish nodules” formed by limestone and
shale. They are represented by the following lithofacies:

– marls with black flint (“facies Suessonien”) of Late Pa-

leocene—Early Eocene age (Durand-Delga et al. 1985),

– Lower-Middle Eocene whitish pelagic marls and / or

marly limestones with black flint nodules and Lutetian black
marls with yellow limestone nodules (Lespinasse 1972; Di-
don et al. 1973; Lespinasse 1975; Durand-Delga et al. 1985).
The Upper Eocene-Lower Oligocene sediments are not well
characterized and need a review of biostratigraphic content,

– Middle Eocene-Oligocene marls with thin-bedded tur-

biditic sandstones (Durand-Delga et al. 1985),

– thick greenish marls and decimeter to meter-sized yel-

lowish-brownish turbiditic sandstones interbedded with
thin-layered marls. These strata have been referred to the
Late Oligocene and the Early Miocene by Durand-Delga et
al. (1985). Their biostratigraphic position is re-examined,
and it indicates an age not older than Early Burdigalian to
Late Serravallian.

Sedimentology

A stratigraphic section has been measured and sampled

within the Lower-Middle Miocene succession of the Tanger
Unit: the Saf Lahmame section, located to the south of Tangi-
er, near the rail road (Geological Map of Tanger-Al Manzla;
X1: 458.95, Y1: 560.30, X2: 459.15, Y2: 560.55 (Figs. 1c, 3)).

Bedding style and thickness, sedimentary structures,

texture and composition have been used to define dif-
ferent turbiditic facies and their associations. Facies

520

ZAGHLOUL et al.

Fig. 2.  Interpreted cross-section through Saf Lahmame—Sequedla area. External Tanger Unit: 1  – marls and marl-limestones with “yel-
lowish limestone nodules” and mudrocks (Campanian—Maastrichtian), 2  – marls to black flint (Suessonian facies) (Upper Paleocene—Lower
Eocene), 3  – marls and turbiditic sandstones (Middle Eocene—Middle Miocene). Numidian Sequence:  4  – brown mudrocks to rare
Tubotomaculum, (Upper Oligocene), 5 – Numidian Flysch (Aquitanian), 6 – grey marls with sandstones to “countourites” facies (Burdi-
galian). Quaternary to Recent deposits: 7 – fluvial terraces and continental alluvial aprons.

classification has been performed according to the
schemes suggested for deep water siliciclastic sediments by
Lowe (1982), Pickering et al. (1989) and Mutti (1992).

Facies description

The section starts with whitish marls with flint, overlain

by marls by a low-angle inverse fault slightly dipping NW
(Figs. 1c, 2). The greyish-greenish marl deposits, about
150 m thick are ensued by a sandstone bed-key up to 13 m
thick, formed by mainly meter- to decimeter-sized yellow-
ish fine-grained sandstones first attributed to the Upper
Oligocene-Lower Miocene boundary by Durand-Delga et
al. (1985) (Figs. 1c, 2).

The vertical arrangement of the facies indicates a fining

upward evolution (FTU; Fig. 3), where the main marly-
arenaceous lithofacies recognized in this section, from the
bottom to the top, are characterized by the three following
stratigraphic intervals:

1 – The lower interval is represented by medium- to

fine-grained and mainly normal graded sandstones (“clas-
sical turbidites” sensu Walker 1978), organized in amal-
gamated beds (5 m of total thickness) with partial Bouma
sequences and with sole marks and fossil traces often oc-
curring at their base. The internal structures of these sand-
stones show essentially base-missing Bouma sequences,
defined by Allen (1984) as “base-cut-out sequences” (T

b—e

b—c/ e

). The sand / mud ratio decreases upward and the pa-

leocurrent analysis indicates the northward (SE to NW and
SW to NE) transport direction (mainly from SE to NW)
which turns into south-eastwards flows (NW to SE) at the
top of this section.

2 – The middle stratigraphic interval is represented by

massive, structureless, flat-floored medium- to fine-grained
sandstones and topped by some crude horizontal lamina-
tions (50 cm to 3 m thick) (locally with load structures) with
a gritty and / or silty-clayey matrix. These latter display dish
structures, centimeter- to decimeter-sized pipe and pillar

structures in the middle and upper parts of their massive di-
vision. A slight normal grading and / or locally some suc-
cessive erosive surges with reworked centimeter-sized mud
clasts occur. Moreover, some decimeter-sized scour-and-fill
structures (about 50 cm) are also present.

At the middle part of this interval, these sandstones (1)

show locally clay chip and mud clast horizons, or (2) they
are scoured by metric amalgamated turbiditic strata or by re-
sidual very fine-grained turbidites whose grain size abrupt-
ly decrease upwards.

3 – The upper stratigraphic interval is characterized

by a fine-grained facies association (150 m thick), repre-
sented by 3 to 5 m thick bundles containing thin-bedded
sandstones alternating with massive white-green marly-
clayey strata. The thin-bedded sandstones are mainly
fine- to very fine-grained, flat floored and sharp-topped,
grading upward to silty-marly strata through fine-grained
parallel laminations. These fine-grained sandstones are
mostly base-missing with T

c/ e

Bouma sequences with

scarce small prod and flute casts.

Facies interpretation

The deposits of the lower stratigraphic interval, usual-

ly considered as products of unstable high density tur-
bidity currents, are interpreted as equivalent to the C

and F

—F

facies of Pickering et al. (1989) and Mutti

(1992) respectively. Their paleoflow fluctuation could
reflect multisource provenance within unsteady marginal
areas of the tilted African paleomargin.

The deposits of the second stratigraphic interval are related

to the evolution of a high density turbidity current (Mutti
1992), where massive structures are interpreted as the results
of very quick deposition for freezing of a dense cohesionless
suspension apparently lacking in post-depositional liquefac-
tion / fluidization (Lowe 1982), under a highly concentrated
flow (Middleton & Hampton 1976; Walker 1978; Lowe
1982; Mutti 1992). The occurrence of scouring and normal

521

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

grading could be interpreted as
turbulent imprint of turbidity cur-
rent where quick packing of
grains justifies the fluid escape
(Lowe 1976; Pickering et al.
1989). The presence of clay chip
and mud clast horizons within
strata could indicate separate flow
portions of different behaviour
(Postma et al. 1988).

The massive sandstones, lo-

cated within this interval, could
be interpreted as products of
sedimentation by continuous
aggradations beneath high-den-
sity turbidity currents with sedi-
ment passing through an active
basal layer of hindered settling
involving grain-flow, fluidized-
flow and liquefied-flow process-
es (Stow et al. 1994).

The restricted range of grain

sizes requires input from a sand-
dominated source and the appar-
ent thickness of some beds results
from amalgamation of several
thinner beds. These deposits are
interpreted as equivalent to the
B

1.1

facies of Pickering et al.

(1989) or to the F

/ F

8—9

/ F

7—8—9

facies of Mutti (1992).

The fine-grained lithofacies of

the third stratigraphic interval are
interpreted as due to slow accumu-
lation of mud and biogenic materi-
als (Stanley & Maldonado 1981;
Thornthon 1984; Pickering et al.
1986). These facies represent the
product of dilute and low concen-
tration turbidity currents, thus cor-
responding to the D

group of

facies of Pickering et al. (1989)
and, also, to the

—T

divisions

Stow & Shanmugam (1980).

Petrography and provenance

Petrographic study of arenaceous samples from the stud-

ied succession has been carried out by means of modal
point counting in thin section in order to recognize the
gross composition and the textural characters of the grains
and to detect the provenance. The modal analyses – first
presented here – have been performed according to the
criteria suggested by Gazzi (1966), Dickinson (1970) and
by Gazzi et al. (1973), in order to minimize the depen-
dence of the rock composition on grain size.

The detrital framework of the analysed rocks is charac-

terized by the presence of an intrabasinal fraction repre-
sented by fossils (carbonate intrabasinal grains, CI) as well

as by glauconite grains and opaque minerals (non-carbonate
intrabasinal grains, NCI) together with a non-carbonate
and carbonate extrabasinal fraction (NCE and CE, respec-
tively; Table 1).

This classification (Zuffa 1980, 1985) is shown in the

NCE—NCI—CI

ternary plot (Fig. 4) representing one of the

main triangles of the tetrahedral three-dimensional configu-
ration suggested for the first-level classification of the areni-
tes

. Thus, all analysed rocks fall in the “sandstone s.s.”

field showing more than 50 % of NCE grains. The Q—F—L
ternary plot, instead, represents a second-level classification
where the different types of sandstones are distinguished.

Fig. 3. Saf Lahmame stratigraphic section. 1 – grey pelites, 2 – thick-bedded turbidite sandstones,
3 – thin-bedded turbidites, 4 – erosional contact and scours, 5 – clay chips, 6 – dish and pillar struc-
tures, 7 – convolute laminations and slump, 8 – load casting, 9 – Bouma sequences, 10 – grain size in
ϕ scale, 11 – location of sandstone samples, 12 – location of mudrock samples, 13 – paleocurrent di-
rections, 14 – main paleoflow directions of slumps, 15 – direction of syn-sedimentary distension.

The numbers within the brackets indicate the content of the CE fraction not represented in the diagram.

522

ZAGHLOUL et al.

The presence of carbonate and non-carbonate intrabasi-

nal fractions is here supported by the following micro-
scopic observations:

– the carbonate intrabasinal grains, locally abundant

(max. 16.0 %) are mainly represented by fossils and, subor-
dinately, by ooids and scarce peloids. The fossils, mainly
planktonic foraminifers and rare bioclasts, are always
present as well preserved single grains and do not occur
within carbonate rock fragments. This can be surely related
to a very short mechanical transport and testifies to their in-
trabasinal character;

– the non-carbonate intrabasinal population is main-

ly represented by glauconite grains (max. 25 %) and by
very low contents of opaque minerals. Glauconite is
usually supposed to be an authigenic mineral formed in
a marine environment, under reducing to slightly oxi-
dizing conditions on the continental shelf (Folk 1974;
Pettijhon 1975; Odin 1985; Kelly & Webb 1999; Hes-
selbo & Huggett 2001). Glauconite particles are nearly
always well rounded and very similar in grain size to
other detrital clasts. Nevertheless, this roundness does
not indicate a highly turbulent environment or pro-
longed transports, but it appears to be closely related to
the stage of growth of the mineral (Odin 1985).

Table 1 lists the compositional parameters adopted for

modal analysis of External Tanger Unit sandstones. Ac-
cording to Zuffa (1980, 1985) the non-carbonate and car-
bonate extrabasinal fractions have also been distinguished
(NCE and CE in Table 1, respectively).

The first population is subdivided into three main com-

positional classes Q, F and L (Quartz, Feldspars and Lithic
fragments) and it is the most abundant, whereas the second
one (CE) is exclusively represented by rare carbonate rock
fragments (max. 6.5 %).

Quartz is the most abundant mineral within the non-car-

bonate extrabasinal fraction (88.7 % to 97.1 %; Q—F—L ter-
nary plot, Table 1 and Fig. 4); so, the analysed rocks can be
referred to sublitharenite / quartzarenite groups (sensu Folk
1974). Accordingly to Basu et al. (1975) and Basu (1985),
two different types of detrital quartz have been distin-
guished: 1 – the monocrystalline quartz grains, subdivided
into varieties of low and high undulosity (i.e.

≤5° or >5° ap-

parent angle of extinction) and 2 – the polycrystalline
quartz grains, with few or many subgrains (

≤ 4 or > 4 ).

The quartz of the analysed rocks is largely represented

by monocrystalline grains. The polycrystallinity quartz
varieties, being less stable, strongly point to selectively
destruction by mechanical factors during prolonged trans-
ports as well as during successive sedimentary cycles (Blatt
& Christie 1963; Connolly 1965; Basu 1985). Thus, the
abundance of monocrystalline quartz grains, mainly char-
acterized by low rather than high undulatory extinction,
can also suggest its polycyclic origin.

Good sorting of the clasts together with moderate to

high roundness of detrital quartz grains seem to confirm
this hypothesis, as emphasized by Suttner et al. (1981) for
the bulk of ancient quartzarenites.

Feldspars are very rare and exclusively represented by

plagioclase in single grains. Few lithic clasts are present,
mainly consisting of fine-grained sedimentary rock frag-
ments ( < 0 .06 mm) as non-carbonate quartzose siltites.

The non-carbonate extrabasinal fraction also includes

low, but important, percentages of ultra-stable heavy min-
erals (zircon, tourmaline and rutile), thus confirming the
high compositional maturity of the analysed rocks.

Interstitial components are mainly represented by carbon-

ate cement and by very low amounts of siliciclastic matrix.
Locally, silica cement is also present as concretionary quartz
overgrowths bordering, in optical and crystallographic conti-
nuity, the ghost outline of the original detrital quartz grains.

Biostratigraphy

Techniques and methods

The biostratigraphical study was performed on calcare-

ous nannofossils present in 11 samples collected from the
Saf Lahmame section.

The samples were prepared following the “C” procedure

of de Capoa et al. (2003) and Eshet (1996) and nannofossils
have been observed by an optical microscope at 1250

× mag-

nification. The biostratigraphic analysis is based exclusive-
ly on the first occurrences (FO), allowing an evaluation of
ages as “not older than …” (de Capoa et al. 2000, 2003).

The studied thin sections of the arenites of the External

Tanger Unit contained mainly well preserved planktonic
foraminifers, filled with a brown matrix. Well preserved ra-
diolaria are also present (SQ7 sample on Fig. 3).

Neogene biostratigraphic schemes for the Mediterra-

nean region of Martini (1971), Okada & Burky (1980),
Berggren et al. (1985, 1995), Perch-Nielsen (1985a,b),
Varol (1989, 1999), Cande & Kent (1992), Fornaciari &
Rio (1996) have been applied.

Planktonic foraminifers

The good preservation of foraminifers and radiolaria indi-

cates that the faunal association is probably in situ and did
not suffer significant transportation. The planktonic foramin-
iferal assemblage consists of globigerinids, Globigerinoides

Fig. 4. Diagrams showing detrital modes of the analysed samples,
according to Zuffa’s.

523

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

Table 1: Modal point counts of the External Tanger Unit arenites.

SQ 1

SQ 2

SQ 3

SQ 4

SQ 5

SQ 6

SQ 7

SQ 8

SQ 10 SQ 11

’

55.1

46.0

47.8

49.7

47.9

55.1

50.9

34.1

41.3

55.3

’’

17.4

23.4

17.9

18.2

18.3

17.5

13.0

11.4

11.8

13.2

’

0.2

1.7

0.8

1.5

0.5

1.6

2.1

2.5

2.2

0.9

’’

1.0

2.7

4.0

2.8

2.4

2.6

2.0

2.8

2.2

1.0

1.2

0.3

2.3

0.5

3.6

1.0

0.4

3.6

3.0

F Ps

0.5

0.7

–

0.2

0.4

–

0.2

0.6

0.3

3.2

2.4

1.9

2.5

2.1

2.8

2.1

1.9

1.7

1.1

0.2

–

0.4

–

0.3

NCE

1.7

1.9

0.8

1.5

3.2

5.6

2.1

0.6

1.1

2.2

4.5

6.5

4.8

3.2

3.9

2.2

2.9

1.8

5.2

0.8

4.1

3.1

3.4

4.0

7.8

3.6

4.5

25.8

4.3

5.9

NCI

1.5

1.0

0.6

1.1

0.5

0.7

0.8

1.0

0.7

0.3

Fo 0.5

–

7.0

0.4

6.5

–

4.8

10.1

14.3

7.0

0.5

–

0.3

–

0.8

–

0.9

–

8.6

9.4

10.7

11.2

5.5

4.5

12.4

8.2

9.5

7.5

100.0

100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

100.0 100.0

NCE

88.5

88.3

82.3

90.2

80.2

93.2

85.1

57.8

72.6

84.8

4.9

7.2

5.4

3.6

4.1

2.3

3.3

2.0

5.8

0.9

NCI

6.1

4.5

5.7

8.8

4.5

6.1

29.2

5.6

6.7

0.5

–

7.8

0.5

6.9

–

5.5

11.0

16.0

7.6

100.0

100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

100.0 100.0

90.1

88.7

91.0

93.0

91.9

93.7

93.3

92.8

89.1

97.1

0.6

0.8

–

0.2

0.5

–

0.4

0.9

0.4

L’

9.3

10.5

8.6

7.0

7.9

5.8

6.7

6.8

10.0

2.5

100.0

100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

100.0

sp. and Orbulina sp. The presence of the genus Orbulina,
first occurrence of which is dated to the Late Langhian—Early
Serravallian, attributes an age not older than Middle Mi-
ocene to the analysed samples. Among benthic foraminiferal
specimens of the Rotaliina and Textulariina suborders are
present. Rotaliina have shells made of low-magnesian calcite
and dominate bathyal environments, while Textulariina have
shells made of agglutinated sand and silt grains and are most
abundant and diverse in neritic environments and at great
abyssal depth below the calcite compensation depth. Conse-
quently, the planktonic and benthic foraminiferal association
is indicative of a basinal environment.

Nannoplankton assemblage

All samples of the Saf Lahmame section are productive.

However, the marker species have been recognized only in
5 samples, in spite of the applied concentration methods.
Most of the specimens are affected by dissolution and are
poorly preserved.

The lower part of the Neogene succession of Saf Lahmame

section starts with green marls with Sphenolithus belemnos as
a marker taxon associated with a nannoplankton assemblage
with Coccolithus pelagicus, Cyclicargolithus floridanus, Dis-
coaster deflandrei (sample T1; Table 2 and Fig. 5). The first

525

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

Fig. 5. Calcareous nannofossils microphotographs from the Saf Lahmame Section (External Tanger Unit). 1—3 – Sphenolithus belemnos
(sample T1, nicols

) ; 4, 5 – Discoaster musicus (sample T5, phase contrast); 6, 7 – Reticulofenestra pseudoumbilicus ( > 7

µm) (sample

T6, nicols

); 8—10 – Calcidiscus macintyrei (sample T6, nicols

); 11—14 – Discoaster kugleri (sample T7; phase contrast);

15, 16 – Reticulofenestra pseudoumbilicus ( > 7

µm) (sample T9, nicols

and phase contrast).

Cyclicargolithus floridanus, Discoaster deflandrei, D. vari-
abilis, D. sp., Reticulofenestra minuta, R. perplexa (Table 2)
and the first occurrence of Calcidiscus macintyrei, R.
pseudoumbilicus ( > 7

µm) (Table 2 and Fig. 5), representa-

tive of the NN6 Zone of Martini (1971), equivalent to the
CN5a

Zone of Okada & Bukry (1980) and to the MNN6

Zone of Fornaciari & Rio (1996). Thus, an age not older
than Middle Serravallian can be inferred for the base of the
uppermost levels of the section.

The higher up levels (T7, T8, T9, T10, T11 samples) are

characterized by a common occurrence of Coccolithus pe-
lagicus, Coronocyclus nitescens, Discoaster deflandrei, D.
variabilis, Ericsonia cava, Helicosphaera carteri, H. cf. sta-
lis, Pontosphaera multipora, Reticulofenestra daviesi, R.
gartneri, R. minuta, R. minutula, R. perplexa, R. pseudoum-
bilicus ( > 7

µm), Sphenolithus abies, Umbilicosphaera rot-

ula.  The first occurrence of Discoaster kugleri (samples T7,
T9; Table 2 and Fig. 5), is representative of the NN7  Zone
of Martini (1971), equivalent to the CN5b  Zone of Okada &
Bukry (1980). It is indicative of an age not older than Late
Serravallian for the uppermost levels of this section.

New biostratigraphic data inferred from both nannofos-

sils and planktonic foraminiferal assemblages indicate
that the lower part of the studied section is not older than
Early Burdigalian. The topmost strata according to nanno-
fossils and foraminiferal associations are not older than
Serravallian. This age is considerably younger than the
Late Oligocene—Aquitanian age first dated by Durand-
Delga et al. (1985).

Discussion and geodynamic context

The Neogene geodynamic evolution of the External

Tanger Unit succession could be reconstructed by means
of new biostratigraphic and petrographic results described

in this paper together with the recent data available in lit-
erature.

Firstly, it is important to underline that the Intra-Rif

sub-Domain, regrouping both the Tanger and Ketama
Units, mainly formed by Mesozoic-Tertiary successions, is
locally well marked by a Paleogene sedimentation hiatus
in the Internal Tanger Unit (Lespinasse 1975) and by the
presence of Lower Miocene conglomerates unconform-
ably overlying the Jurassic-Neocomian successions locat-
ed in the more external areas of the Ketama Unit and
belonging to the Meso-Rif Units (Tiflouest area, south of
the Ketama Unit; Favre 1992).

The above mentioned unconformity could highlight the

occurrence of a pre-Miocene tectonic event, which also
seems to be recorded within the Internal Tanger Unit, by a
Paleogene sedimentation hiatus, while the sedimentation
is continuous synchronously up to the Serravallian within
the External Tanger Unit.

This Paleogene hiatus and the unconformities occurring

within the External Domain could be interpreted as the re-
sult of the onset of the Maghrebian subduction, where the
African paleomargin and the related thinned and partially
“oceanic” crust (Michard et al. 1992; Zaghloul et al. 2003)
start to be subducted beneath the southern-occidental end-
ing of the “Mesomediterranean Terrane” microplate main-
ly during the Late Oligocene (Chalouan & Michard 2004
and bibliography therein).

Later, during the Neogene, the paroxysmal deformation

phase responsible for the closure of the Flysch Basin and
for the thrusting of the flysch nappes onto the External
Domain mainly occurred during the Late Burdigalian and
Langhian p.p. (Zaghloul 2002; Zaghloul et al. 2004). This
main compressive phase is post-dated by the Middle Mi-
ocene “post-nappes” Beni Issef Formation (quartzarenites
and marls with resedimented cobbles and boulders deriv-
ing from flysch nappes), stratigraphically resting on the

526

ZAGHLOUL et al.

Intra-Rif Units (Tanger and Loukkous Units) at the edge of
the Basin Flysch accretionary prism (Durand-Delga &
Lespinasse 1965; Didon & Feinberg 1979).

Successively, the Neogene deformation reaches the In-

tra-Rif and Meso-Rif sub-Domains, whose Lower-Middle
Miocene syn-tectonic deposits have been progressively
involved within the mainly westwards and southwestwards
thrusting since the Late Serravallian (BenYaich et al. 1988;
BenYaich 1991; Tejera de Leon 1993; Favre 1995; Chal-
ouan et al. 2001; Tejera de Leon & Duée 2003).

The most external area of the External Domain plays the

role of proto-Rif foredeep of the former accretionary proto-
Rif prism structured from the Late Burdigalian up to the
Early—Middle Tortonian. This compressive event is post-
dated by the occurrence of the Upper Tortonian “post-
nappes” deposits unconformably lying on the Intra-Rif,
Meso-Rif and Pre-Rif Units (Mediouni & Wernli 1978;
Feinberg 1986; Kerzazi 1994).

Concluding remarks

The Neogene siliciclastic succession of the External

Tanger Unit, ranging in age from Early Burdigalian to
Late Serravallian, displays a depositional trend suggesting
a general upward increase of sedimentary influx into a
subsiding area.

Sedimentological features of the arenites of the analy-

sed section reflect a continual deposition by aggradation-
al processes, from high-density turbidity currents. In
contrast, the fine-grained lithofacies (massive white-green
marly-clayey beds and thin-bedded arenites) reflect slow
accumulation of mud and biogenic materials by diluted
and low concentration turbidity currents.

The paleocurrents indicate transport directions mainly to-

wards the NW and, subordinately, to the SE. This fluctua-
tion could reflect a multisource provenance from unstable
marginal areas of the tilted African margin.

The petrographic characters of the arenites permit to re-

fer their composition to the sublitharenite / quartzarenite
groups with the omnipresent occurrence of glauconite grains.

Even if glauconite is not a precise indicator of depth be-

cause its occurrence has also been recognized at more than
800 m of depth (Porrenga 1967; Odin & Matter 1981;
Odin 1985), it is always associated, in the analysed areni-
tes, with planktonic foraminifers. This testifies to the deep
water origin of the glauconite.

These data allow us to suppose that the studied Neo-

gene strata of the External Tanger Unit have been deposit-
ed on the African continental shelf probably in the middle
and lower bathyal zones.

The provenance of this siliciclastic material seems to be

exclusively related to the African Craton. This hypothesis,
is supported by the dominant occurrence of well rounded
monocrystalline quartz grains and by the presence of low,
but important, percentages of ultra-stable heavy minerals
(zircon, tourmaline and rutile), both testifying to long se-
lective mechanical transports due to successive sedimen-
tary cycles.

Furthermore, the petrographic characters and composi-

tions of the analysed arenites are very similar to those ob-
served within Numidian and Numidian-like sandstones of
the Betic and Apenninic-Maghrebian Chains (Chiocchini
et al. 1978; Pendon 1978; Loiacono et al. 1983; Ardito et
al. 1985; Cazzola & Critelli 1986—87; Carbone et al.
1990; Moretti et al. 1991; Guerrera et al. 1992).

Finally, the Burdigalian and Langhian-Serravallian

strata belonging to the Neogene succession of the Exter-
nal Tanger Unit have been involved in the westward
thrusting carrying the Flysch Basin nappes and the inter-
nal part of the External Domain onto the more external
part of the latter.

Acknowledgments:

Financial support was provided by the

Italian MURST and by the U.F.R. “Géologie Méditer-
ranéenne” as grants to D. Puglisi (University of Catania, Ita-
ly) and to M.N. Zaghloul (Université AbdelMalek Essaadi
of Tétouan, Morocco), respectively. We thank J.J. Cornée
(University of Lyon I), D. Frizon de Lamotte (University of
Cergy-Pontoise), the responsible editor of Geologica Car-
pathica T. Peryt (Geological Institute of Warszawa, Poland)
and an anonymous Referee for their careful revision of the
manuscript. Authors are also grateful to V. Perrone (Univer-
sity of Urbino, Italy) and to Stuart J. Jones (University of
Durham, U.K.) for the careful discussions and comments
and for the revision of the English text of this paper.

References

Allen J.R.L. 1984: Sedimentary structures, their character and phys-

ical basis. Development in sedimentology. Elsevier Co., Am-
sterdam, Vol. I, 1—593, Vol. II, 1—663.

Andrieux J. 1971: La structure du Rif central. Etude des relations

entre la tectonique de compression et les nappes de glissement
dans un tronçon de la chaîne alpine. Notes Mém. Serv. Géol.
Maroc 235, 1—155.

Ardito M.C., Colaluce G., Dazzaro L., Del Gaudio V., Lops B.,

Moresi M., Piccarreta G. & Rapisardi L. 1985: The sandstones
of the Daunian Apennines – geological, mineralogical and
petrographic observations. Atti 3 Conv. Naz. “Attivitá estrattiva
dei minerali di II categ.”, Bari 1985, ANIM Ed. PEI, Parma,
50—53 (in Italian).

Azdimoussa A., Bourgois J., Poupeau G. & Montigny R. 1998: His-

toire thermique du massif de Kétama (Maroc): sa place en Af-
rique du Nord et dans les Cordillères bétiques. C.R. Acad. Sci.
Paris 326, 847—853.

Basu A. 1985: Reading provenance from detrital quartz. In: Zuffa

G.G. (Ed.): Provenance of arenites. Reidel, Dordrecht, 231—247.

Basu A., Young S.W., Suttner L.J., James W.C. & Mack G.K. 1975:

Re-evaluation of the use of undulatory extinction and poly-
crystallinity in detrital quartz for provenance interpretation. J.
Sed. Petrology 45, 873—882.

BenYaich A. 1991: Evolution tectono-sédimentaire du Rif externe

centro-occidental (régions de MS’ila et Ouezzane, Maroc): la
marge africaine du Jurassique au Crétacé; les bassins néogènes
d’avant-fosse. Thèse Sci., Univ. Pau, Pau, 1—308.

BenYaich A., Duée G., Souquet P. & Fondcave Wallez J.M. 1988:

Les grès de Zoumi: dépôts turbiditiques d’un avant-fosse mio-
cène (Burdigalien-Serravalien) dans le Rif occidental (Maroc).
C.R. Acad. Sci. Paris 309, II, 8, 1819—1825.

527

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

BenYaich A. 1991: Evolution tectono-sédimentaire du Rif externe

centro-occidental (Régions de Msila et Ouezzane, Maroc). La
marge africaine du Jurassique au Crétacé inférieur. Les bassins
Néogènes d’Avant-fosse. Thèse d’État, Univ. Pau, Pau, 1—308.

Berggren W.A., Kent D.V. & Van Couvering J.A. 1985: Neogene

geochronology and chronostratigraphy. In: Schelling N.J.
(Ed.): The chronology of the geological record. Geol. Soc.
London Mem. 10, 211—260.

Berggren W.A., Kent D.V., Swisher C.C. III. & Aubry M.P. 1995:

A revised Cenozoic geochronology and chronostratigraphy.
In: Berggren W.A., Kent D.V., Aubry M.P. & Hardenbol J.
(Eds.): Geochronology, time scales and global Correlation.
SEPM Spec. Publ. 54, 129—212.

Blatt H. & Christie J.M. 1963: Undulatory extinction in quartz of igne-

ous and metamorphic rocks and its significance in provenance
studies of sedimentary rocks. J. Sed. Petrology 33, 559—579.

Boccaletti M., Conadera C., Dainelli P. & Gocev P. 1985: Tectonic

map of the Western Mediterranean Area. Scale 1:2,500,000.
Litogr. Artist. Cartogr., Firenze.

Bourgois J., Chauve P. & Dubois M. 1971: Découverte du substra-

tum Jurassique et crétacé inférieur de l’Unité de Algarrobo et
origine ultra-pénibétique de cette unité. C.R. Acad. Sci. Paris
273, 295—297.

Cande S.C. & Kent D.V. 1992: A new geomagnetic polarity time

scale for the Late Cretaceous and Cenozoic. J. Geophys. Res.
100, 6093—6095.

Carbone S., Catalano S., Grasso M., Lentini F. & Monaco C. 1990:

Geological map of the Centro-oriental Sicily. S.EL.CA., Firenze.

Carmisciano R., Coccioni R., Corradini D., d’Alessandro A.,

Guerrera F., Loiacono F., Moretti E., Puglisi D. & Sabato L.
1987: New data from the Lower Miocene “mixed succes-
sions” from Algeria (Great Kabylia) and from Sicily (Ne-
brodi Mts.): comparison with similar turbiditic successions
from the Gibraltar Arc and lucanian Apennines. Mem. Soc.
Geol. Ital. 38, 551—576 (in Italian).

Cazzola C. & Critelli S. 1986—87: Lithostratigraphy and petrology

of the Oligocene-Miocene turbiditic quartzarenites of Asilah
(Rifian Chain, north-western Morocco). Mineral. Petrogr.
Acta 30, 203—226.

Chalouan A., Michard A., Feinberg H., Montigny R. & Saddiqi O.

2001: The Rif mountain building (Morocco): a new tectonic
scenario. Bull. Soc. Géol. France 172, 5, 603—616.

Chaouni A. 1996: Apport des données Landsat M.S.S., RADAR

ERS1-SAR; Modèles numériques de terrain; Morphométriques
structurales de Terrain à la compréhension de la cinématique
des principales failles de la Péninsule de Tanger depuis
L’Oligocène supérieur jusqu’à l’Actuel. Diplôme d’Etudes
Supérieures de 3

ème

Cycle. Univ. Med V. Rabat, Rabat, 1—265.

Chiocchini U., Franchi R., Guerrera F., Rayan W. & Vannucci S.

1978: Geology of some Cretaceous-Tertiary turbiditic succes-
sions belonging to the “Maurétaniens Flysch” and to the
“Nappe Numidienne” of northern Rif (Morocco). Studi Geol.
Camerti IV, 37—66 (in Italian).

Connolly J.R. 1965: The occurrence of polycrystallinity and undu-

latory extinction on quartz in sandstones. J. Sed. Petrology 35,
116—135.

Critelli S. 1985: Provenance of the Oligocene-Miocene turbidites of

the external domain and of the Numidian Nappe of the Rif
(north-western Morocco). Tesi di Laurea, Università della Ca-
labria, 1—128 (in Italian).

de Capoa P., Di Donato V., Di Staso A., Giardino S. & Rinaldi S.

2003: Preparation techniques and methodological approach to
calcareous nannoplankton analysis in silico and calciclastic tur-
bidites. Courier Forschungsinst. Senckenberg 244, 115—137.

de Capoa P., Di Staso A. & Giardino S. 2000: Preparation techniques

and methodological approach to calcareous nannoplankton

analysis of turbiditic sediments. In: 8

INA Conference, Bre-

men 2000, Programme and Abstracts. J. Nannoplankton Res.
22, 2, 89.

Dickinson W.R. 1970: Interpreting detrital modes of greywacke

and arkose. J. Sed. Petrology 40, 2, 695—707.

Didon J. & Feinberg H. 1979: Données nouvelles sur l’âge et la

signification géodynamique du Miocène des Béni-Issef: im-
portance de la tectonique burdigalienne dans le Rif septentri-
onal (Maroc). C.R. Somm. Soc. Géol. France 7, 21, 183—187.

Didon J. & Hoyez B. 1978: Les séries à facies mixte, numidien et

gréso-micacé, dans le Rif occidental (Maroc). C.R. Somm. Soc.
Géol. France 6, 304—307.

Didon J., Durand-Delga M. & Kornprobst J. 1973: Homologies

géologiques entre les deux rives du Détroit de Gibraltar. Bull.
Soc. Géol. France 15, 77—105.

Durad-Delga M. 1972: La courbure de Gibraltar extrémité occiden-

tale des chaînes alpines unit l’Europe et l’Afrique. Eclogae
Géol. Helv. 65, 267—278.

Durand-Delga M. & Lespinasse P. 1965: Le Miocène des Beni-Issef

(Rif septentrional) et ses rapports avec la nappe numidienne.
C.R. Somm. Soc. Géol. France 10, 321—323.

Durand-Delga M. & Fontboté J.M. 1980: Le cadre structurale de la

Méditerranée occidentale. In: Auboiin J., Debelmas & Latreille
M. (Eds.): Géologie des chaînes alpines issues de la Tèthys.
26

Congr. Géol. France. Mém. BRGM 15, 67—85.

Durand-Delga M. 1972: La courbure de Gibraltar, extrémité occi-

dentale des chaines alpines, unit l’Europe et l’Afrique.
Eclogae Géol. Helv. 65, 2, 267—278.

Durand-Delga M. 1980: La Méditerranée occidentale: étape de sa

génèse et problème structuraux liées à celle ci. Livre Jubilaire
Soc. Géol. France, Mém. h-s Soc. Géol. France 10, 203—224.

Durand-Delga M., Didon J., Feinberg H., Magne J., Medioni R.,

Suter G. & Werneli R. 1985: Carte Géologique du Rif Tanger-
Al Manzla 1:50,000. Not. Mém. Serv. Géol. Maroc 294, 1985.

Durand-Delga M., Hottinger L., Marcais J., Mattauer M., Milliard Y.

& Suter G. 1960—1962: Données actuelles sur la structure du
Rif. Livre Mém. P. Fallot, Mém. Soc. Géol. France 1, 399—422.

El Mrihi A. 1995: Structures alpines des zones externes et des

nappes de flyschs à l’Ouest de la chaîne du Haouz (Rif septen-
trional Maroc). Thèse 3

ème

cycle, Univ. Med V, Rabat, 1—149.

Eshet Y. 1996: Obtaining rich nannofossil assemblages from “bar-

ren” samples: processing organic-rich rocks in nannofossil in-
vestigations. J. Nannoplankton Res. 18, 17—21.

Favre P. 1992: Géologie des massifs calcaires situés au front Sud de

l’unité de Kétama (Rif, Maroc). Thèse, Publ. Dépt. Géol. Pal.,
Univ. Genève, Vol. 138, 11, 2.

Favre P. 1995: Analyse quantitative du rifting et de la relaxation

thermique de la partie occidentale de la marge transformante
nord-africaine: le Rif externe (Maroc). Comparaison avec la
structure actuelle de la chaîne. Geodinamica Acta 8, 59—81.

Feinberg H. 1986: Les séries tertiaires du Prérif et des dépendances

post-tectoniques du Rif (Maroc). Biostratigraphie, paléogéog-
raphie et aperçu tectonique. Not. Mém. Serv. Géol. Maroc 315,
1—192.

Folk R.L. 1974: Petrology of sedimentary rocks. Hemphill’s, Aus-

tin, Texas, 1—182.

Fornaciari E. & Rio D. 1996: Latest Oligocene to the Lower Middle

Miocene quantitative calcareous nannofossil biostratigraphy in
the Mediterranean region. Micropaleontology 42, 1—37.

Frizon de Lamotte D., Andrieux J. & Guezou J.-C. 1991: Cinéma-

tique des chevauchements néogènes dans l’Arc bético-rifain:
discussion sur les modèles géodynamiques. Bull. Soc. Géol.
France 169, 611—626.

Gazzi P. 1966: The upper Cretaceous Flysch sandstones (Modena

Apennine); comparison with the Monghidoro Flysch. Mineral.
Petrogr. Acta 12, 69—97 (in Italian).

528

ZAGHLOUL et al.

Gazzi P., Zuffa G.G., Gandolfi G. & Paganelli L. 1973: Provenance

and dispersal of the sands along the Adriatic littoral between
the Isonzo and Foglia rivers: regional framework. Mem. Soc.
Geol. Ital. 12, 1—37 (in Italian).

Guerrera F., Coccioni R., Loiacono F., Moretti E. & Puglisi D.

1987: Oligocene-Miocene Maurétanien-like flysch units (syn-
orogenic and lateorogenic) of the Betic Cordigliera (Spain)
and eastern Tell (Algeria): comparison in the Rif, in the north-
ern sicilian chain and in the southern Apennines. Mem. Geol.
Soc. Ital. 38, 521—550 (in Italian).

Guerrera F., Loiacono F., Moretti E. & Puglisi D. 1992: The Nu-

midian Nappe in the Maghrebian Chain: state of the art. Boll.
Soc. Geol. Ital. 111, 217—253.

Guerrera F., Martin Algarra A. & Perrone V. 1993: Late Oli-

gocene-Miocene syn-/-late-orogenic successions in Western
and Central Mediterranean Chains from the Betic Cordillera
to the Southern Apennines. Terra Nova 5, 525—545.

Hesselbo S.P. & Huggett J.M. 2001: Glaucony in ocean-margin se-

quence stratigraphy (Oligocene—Pliocene offshore New Jersey
U.S.A, ODP Leg 174a). J. Sed. Res. 71, 599—607.

Hottinger L. & Suter G. 1961: La structure de la Zone prérifaine au

S du Moyen Ouergha. C. R. Acad. Sci. Paris 254, 140—142.

Kelly J.C. & Webb J.A. 1999: The genesis of glaucony in the Oli-

go—Miocene Torquay Group Southeastern Australia: petro-
graphic and geochemical evidence. Sed. Geol. 125, 99—114.

Kerzazi K. 1994: Etude biostratigraphique du Miocène sur la base

des foraminifères planctoniques et nannofossiles calcaires
dans le Prérif et la marge atlantique du Maroc (site 547A du
DSDP Leg 79) aperçu sur leur paléoenvironnement. Thèse,
Univ. P. et M. Curie, Paris, 1—230.

Leblanc D. 1979: Etude géologique du Rif externe oriental au nord

de Taza (Maroc). Not. Mém. Serv. Géol. Maroc 281, 1—160.

Lespinasse P. 1972: Problèmes stratigraphiques et structuraux

posés par l’Eocène de la région de Chaouen. C. R. Acad. Sci.
Paris 274, 355—358.

Lespinasse P. 1975: Géologie des zones externes et des flyschs

entre Chaouen et Zoumi (Centre de la Chaîne Rifaine du Ma-
roc). Thèse d’Etat, Université de Paris, 1—284.

Loiacono F., Paglionico A. & Pellegrino M.C. 1983: Quartzareni-

tes of the Numidian Flysch in the Campomaggiore area (PZ):
investigation for their industrial utilization. Geol. Appl. Idro-
geol. 18, 1, 73—80 (in Italian).

Lowe D.R. 1976: Subaqueous liquefied and fluidized sediment

flows and their deposits. Sedimentology 23, 285—308.

Lowe D.R. 1982: Sediment gravity flows: II. Depositional models

with special reference to the deposits of high-density turbidi-
ty currents. J. Sed. Petrology 52, 279—297.

Martini E. 1971: Standard Tertiary and Quaternary calcareous

nannoplankton zonation. In: Farinacci A. (Ed.): Proceedings
II Planktonic Conference, Roma 1970. Edizioni Tecnoscien-
za, Roma, 739—777.

Mediouni R. & Wernli R. 1978: Etude géologique du bassin post-

nappe Mio-pliocène de Charf-el-Akab (Province de Tanger,
Maroc). Not. Serv. Geol. Maroc, No. 275, 40.

Michard A. & Chalouan A. 2004: The Alpine Rif Belt (Morocco): a

case of mountain building in a aubduction-aubduction-trans-
form fault triple junction. Pure Appl. Geophys. 161, 489—519.

Michard A., Feinberg H., El Azzab D., Bouybaouene M. & Sad-

diqui O. 1992: A serpentinite ridge in a collisional paleomar-
gin setting: the Beni Malek massif. external Rif, Morocco.
Earth Planet. Sci. Lett. 113, 435—442.

Michard A., Chalouan A., Feinberg H., Goffé B. & Montigny R.

2002: How does the alpine belt end between Spain and Moroc-
co? Bull. Soc. Géol. France 173, 1, 3—15.

Middleton G.V. & Hampton M.A. 1976: Subaqueous sediment trans-

port and deposition by sediment gravity flows. In: Stanley D.J.

& Swift D.J.P. (Eds.): Marine sediment transport and environ-
mental management. John Wiley & Sons, New York, 197—217.

Moretti E., Coccioni R., Guerrera F., Lahondere J.C., Loiacono F.

& Puglisi D. 1991: The Numidian Sequence between Guelma
and Constantine (Eastern Tell, Algeria). Terra Res. (Terra
Nova) 3, 153—165.

Mutti E. 1979: Turbidites et cônes sous-marins profonds. In:

Homewoods P. (Ed.): Sédimentation Détritique (Fluviatile,
Littorale et Marine). Inst. Géol., Univ. Fribourg, 353—419.

Mutti E. 1992: Turbidite sandstones. Agip S.p.A Milano, Istituto

Geol., Univ. Parma, 1—275.

Odin G.S. & Matter A. 1981: De glauconiarum origine. Sedimen-

tology 28, 611—641.

Odin G.S. 1985: Significance of green particles (glaucony, ber-

thierine, chlorite) in arenites. In: Zuffa G.G. (Ed.): Prove-
nante of arenites. Reidel, Dordrecht, 279—307.

Okada H. & Bukry D. 1980: Supplementary modification and in-

troduction of code numbers to the low-latitude Coccolith
biostratigraphic zonation (Bukry 1973, 1975). Mar. Micro-
paleontology 5, 321—325.

Pendon J.G. 1978: Sedimentation turbiditica en las unidades del

Campo de Gibraltar. Thesis Doct. Univ. Granada, 1—260.

Perch-Nielsen K. 1985a: Mesozoic calcareous nannofossils. In:

Bolli H.M., Saunders J.B. & Perch-Nielsen K. (Eds.): Plank-
ton stratigraphy. Cambridge University Press, 329—426.

Perch-Nielsen K. 1985b: Cenozoic calcareous nannofossils. In:

Bolli H.M., Saunders J.B. & Perch-Nielsen K. (Eds.): Plank-
ton stratigraphy. Cambridge University Press, 427—554.

Pettijohn E.J. 1975: Sedimentary rocks. Harper International Edi-

tion, Harper & Row, Publishers, Inc., New York, 1—628.

Pickering K.T., Hiscott R.N. & Hein F.J. 1989: Deep marine envi-

ronments: clastic sedimentation and tectonics. Unwin Hyman
Ltd., London, 1—416.

Pickering K., Stow D.A.V., Watson M. & Hiscott R. 1986: Deep-

water facies, processes and models: a review and classifica-
tion scheme for modern and ancient sediments. Earth Sci.
Rev. 23, 75—174.

Porrenga D.H. 1967: Glauconite and chamosite as depth indica-

tors in the marine environment. Mar. Geol. 5, 495—501.

Postma G., Nemec W. & Kleinspehn K.L. 1988: Large floating

clast in turbidites: a mechanism for their emplacement. Sed.
Geol. 56, 47—61.

Puglisi D., Zaghloul M.N. & Maate A. 2001: Evidence of sedimenta-

ry supply from plutonic sources in the Oligocene-Miocene flysch
of the Rifian Chain (Morocco): provenance and palaeogeo-
graphic implications. Boll. Soc. Geol. Ital. 120, 55—68.

Ricci Lucchi F. 1995: Sedimentographica: Photographic atlas of

sedimentary structures. 2

Edition. Casebound Ed. Colombia

Univ. Press, 1—251.

Saadi S.E.M., Hilali E.A. & Boudda A. 1980: Carte géologique du

Rif. Ministère d’Energie et des Mines Maroc. Serv. Géol. Not.
Mém. No. 254 a,b. Echelle 1:500,000.

Saji R. 1993: Evolution tectonique post-nappes dans le Rif septentri-

onal (Maroc): ses effets sur l’ouverture de la Mer d’Alboran.
Thèse 3

ème

cycle, Univ. Med V Rabat 1—152.

Stanley D.J. & Maldonado A. 1981: Depositional models for fine-

grained sediments in western Hellenic Trench, Eastern Mediter-
ranean. Sedimentolgy 28, 273—290.

Stow D.A.V., Braackenburg N.E. & Johansson M. 1994: Atlas of

deep water, massives sands. Unpublished report, Southampton
University.

Stow D.A.V. & Shanmugam G. 1980: Sequence of structures in fine-

grained turbidites: comparison of recent deep sea and ancient
flysch sediments. Sed. Geol. 25, 23—42.

Suter G. & Fiechter G. 1966: Le Rif Méridional atlantique. Not. Serv.

Géol. Maroc 183, 24, 7—17.

529

LOWER—MIDDLE MIOCENE STRATA WITHIN THE EXTERNAL TANGER UNIT (MOROCCO)

Suttner L.J., Basu A. & Mack G.H. 1981: Climate and the origin of

quartz arenites. J. Sed. Petrology 51, 4, 1235—1246.

Tejera de Leon J. 1993: Les Bassins Néogènes d’Avant-Pays du

Rif exteme occidental liés à la transformante Jebha-Arbaoua
(Maroc). Thèse d’Etat es-Sciences, Univ. de Pau et des Pays
de l’Adour, 1—323.

Tejera de Leon J. & Dueé G. 2003: Relationships between the

Neogene foredeep basins of the western external Riffian belt
related to the Arbaoua-Jebha transform fault. Consequence
for the interpretation of the evolution of the riffian belt.
Trav. Inst. Sci. Rabat, Série Géol. & Géogr. Phys. No. 21,
47—675.

Thornthon S.E. 1984: Basin model for hemipelagic sedimentation

in a tectonically continental margin: Santa Barbara Basin,
California continental Borderland. In: Stow D.A.V. & Piper
D.J.W. (Eds.): Fine-grained sediments: processes and facies.
Geol. Soc. London Spec. Publ. 15, 377—394.

Varol O. 1989: Paleocene calcareous nannofossil biostratigraphy.

In: Crux J.A. & Van Heck S.E. (Eds.): Nannofossils and their
applications. British Micropaleontological Society Series. El-
lis Horwood Limited, Chichester, 267—310.

Varol O. 1999: Palaeogene. In: Bown P.R. (Ed.): Calcareous nanno-

fossil biostratigraphy. Kluwer Academic Publishers, 200—218.

Walker R.G. 1978: Deep-water sandstones facies and ancient sub-

marine fans: Models for exploration for stratigraphic traps.
AAPG Bull. 62, 6, 932—966.

Wildi W. 1983: La chaîne tello-rifaine (Algérie, Maroc, Tunisie):

structure, stratigraphie et évolution du Trias au Miocène. Rev.
Géol. Dyn. Géogr. Phys. 24, 3, 201—297.

Zaghloul M.N. 2002: La sédimentation silicoclastique Oligo-Mio-

cène de type “Flysch” dans le Rif, “Bassin des Flyschs” et
“Zones Internes” (Rif, Maroc): évolution et corrélations à
l’échelle de la Chaîne Maghrébide. Thèse d’Etat, Univ. Ab-
delMalek Essaadi, Tétouan (Maroc), 1—329.

Zaghloul M.N., Guerrera F., Loiacono F., Maiorano P. & Puglisi

D. 2002: Stratigraphy and petrography of the Beni Ider Flysch

in the Tétouan area (Rif Chain, Morocco). Boll. Soc. Geol.
Ital. 121, 69—85.

Zaghloul M.N. & Puglisi. D. 2003: Le Flysch Oligo-miocène de

Beni Ider (Rif, Maroc): Evidence d’une Alimentation à partir
des Roches Plutoniques corrélation à travers la chaîne bético
maghrébine et implications paléogéographiques. Trav. Inst.
Sci. Rabat, Série Géol. & Géogr. Phys. 21, 67—75.

Zaghloul M.N., Amri I., El Moutchou B., Mazzoli S., Ouazani-

Touhami A. & Perrone V. 2003: First evidence of Upper Ju-
rassic-Lower Cretaceous oceanic—derived rocks in the
Ketama Unit (External Rif Zones; Morocco). International
Congress 3MA, Casablanca 8—10

Mai 2003, Maroc, 70.

Zaghloul M.N., Di Staso A.,

de Capoa P. &

Perrone V. 2004: Mise

en évidence du Burdigalien supérieur dans les successions
gréso-marneuses et dans les marnes à silexites de Dchar Foual
(Flysch de Beni Ider, Domaine du Flysch, Rif Septentrional
– Maroc). Colloque à la mémoire de Feue Anne Faure-
Muret “Evolution des connaissances de la géologie du Maroc
du temps des pionniers à nos jours”. Rabat, Ministère
d’Energie et des Mines, 5—6

October 2004, 74—76.

Zakir A. & Chalouan A. 2003: Modélisation tectonique des rampes

frontales et latérales dans les séries Néogènes du Rif Externe
Nord – Occidental entre El Ksar-El Kbir et Asilah (Maroc):
Rôle de l’accident de Jebha dans la structure de cette zone.
Third Congress of Regional Commitee on Atlantic Neogene
Stratigraphy “The Atlantic Neogene in the XXI

Century: State

of the Art”, Tetouan, Morocco, 19—25

September 2003.

Zakir A. 2004: Contribution à l’étude géologique des bassins turbidi-

tiques tertiaires de la région d’El Ksar-El Kebir (Rif externe
nord-occidental, Maroc). Approche sédimentologique et struc-
turale. Thèse Doct. Univ. Mohamed V, Rabat, Maroc, 1—170.

Zuffa G.G. 1980: Hybrid arenites: their composition and classifi-

cation. J. Sed. Petrology 50, 1, 21—29.

Zuffa G.G. 1985: Optical analyses of arenites: influence of meth-

odology on compositional results. In: Zuffa G.G. (Ed.):
Provenance of arenites. Reidel, Dordrecht, 165—189.