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This article was downloaded by: [Bagherpour, Borhan]On: 10 June 2011Access details: Access Details: [subscription number 938493264]Publisher Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Historical BiologyPublication details, including instructions for authors and subscription information:http://www.informaworld.com/smpp/title~content=t713717695
Facies, paleoenvironment, carbonate platform and facies changes acrossPaleocene Eocene of the Taleh Zang Formation in the Zagros Basin, SW-IranBorhan Bagherpoura; Mohammad R. Vaziria
a Department of Geology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran
First published on: 09 June 2011
To cite this Article Bagherpour, Borhan and Vaziri, Mohammad R.(2011) 'Facies, paleoenvironment, carbonate platformand facies changes across Paleocene Eocene of the Taleh Zang Formation in the Zagros Basin, SW-Iran', HistoricalBiology,, First published on: 09 June 2011 (iFirst)To link to this Article: DOI: 10.1080/08912963.2011.587185URL: http://dx.doi.org/10.1080/08912963.2011.587185
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Facies, paleoenvironment, carbonate platform and facies changes across Paleocene Eoceneof the Taleh Zang Formation in the Zagros Basin, SW-Iran
Borhan Bagherpour* and Mohammad R. Vaziri
Department of Geology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran
(Received 30 March 2011; final version received 8 May 2011)
The Paleocene–Eocene Taleh Zang Formation of the Zagros Basin is a sequence of shallow-water carbonates. We havestudied carbonate platform, sedimentary environments and its changes based on the facies analysis with particular emphasison the biogenic assemblages of the Late Paleocene Sarkan and Early Eocene Maleh kuh sections. In the Late Paleocene, ninemicrofacies types were distinguished, dominated by algal taxa and corals at the lower part and larger foraminifera at theupper part. The Lower Eocene section is characterised by 10 microfacies types, which are dominated by diverse largerforaminifera such as alveolinids, orbitolitids and nummulitids. The Taleh Zang Formation at the Sarkan and Maleh kuhsections represents sedimentation on a carbonate ramp.
The deepening trends show a gradual increase in perforate foraminifera, the deepest environment is marked by themaximum occurrence of perforate foraminifers (Nummulites), while the shallowing trends are composed mainly ofimperforate foraminifera and also characterised by lack of fossils in tidal flat facies.
Based on the facies changes and platform evolution, three stages are assumed in platform development: I; algal andcoralgal colonies (coralgal platform), II; coralgal reefs giving way to larger foraminifera, III; dominance of diverse andnewly developing larger foraminifera lineages in oligotrophic conditions.
Keywords: Taleh Zang Formation; Paleogene; carbonate platform; Tethys; facies analysis; larger benthic foraminifera
1. Introduction
Paleogene is a period of the Earth history in which the close
interaction between global climate changes and biological
evolution can be clearly recognised (Pujalte et al. 2009).
The Paleocene–Eocene (P–E) interval was a time of intense
changes in shallow-water carbonate settings. The Paleo-
cene–Eocene Thermal Maximum (PETM; Norris and Rohl
1999; Rohl et al. 2000) was characterised by a global 5–88C
warming of sea surface temperature in less than 10 ka
(e.g. Rohl et al. 2000). The PETM coincided with a dramatic
decrease of ,2 to 4‰ in d 13C values in which the decrease
has been measured in sedimentary rocks worldwide, called
the ‘carbon isotopic excursion’ (CIE; e.g. Kennett and Stott
1991; Koch et al. 1992; Bralower et al. 1995; Katz et al.
1999). CIE probably resulted from the rapid dissociation of
methane at the sea floor (Dickens et al. 1995; Bains et al.
1999). It was followed by an exceptional return to
preexcursion d 13C value as excess 12C was eventually
transferred out of the ocean–atmosphere carbon reservoir,
which is consistent with the estimates of the modern
residence time of carbon (Dickens 2000). From a biotic point
of view, the P–E transition was a time of widespread
diversification in terrestrial and marine biotas. Many
established clades also greatly expanded their geographical
ranges throughout this interval (Macleod et al. 2002). Open
marine organisms (planktic and benthic foraminifera,
dinoflagellates, calcareous nanoplankton) show extinction
and diversification patterns (e.g. Thomas 1998; Crouch et al.
2001; Bralower 2002; Kelly 2002). The transition from the
Paleocene to the Eocene witnessed the largest extinction
event affecting the deep water benthic foraminifera during
the last 90 Myr, the so-called Benthic Extinction Event
(BEE; Galeotti et al. 2004).
Many studies have been conducted on P–E setting, but
mainly focusing on deeper water environments. Scheibner
et al. (2005) analysed Paleocene/Eocene sections in
the Galala Mountains in Egypt (southern Tethys), and
suggested an interplay between rising temperatures and
changes in the trophic resource regime and their effects on
biota (especially corals and larger foraminifera) and
long-term evolutional changes in larger foraminifera as the
main causes for the changes in shallow-water facies.
Furthermore, for the Egyptian platform they postulated
an evolution of the shallow-water platform across the
Paleocene–Eocene boundary in three successive stages,
characterised by changing biota.
In this study, we focus on sedimentary environments,
foraminiferal paleoecology and carbonate platform of
lower Paleogene Taleh Zang Formation of shallow-water
ISSN 0891-2963 print/ISSN 1029-2381 online
q 2011 Taylor & Francis
DOI: 10.1080/08912963.2011.587185
http://www.informaworld.com
*Corresponding author. Email: [email protected]
Historical Biology
iFirst article, 2011, 1–22
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carbonate in the Zagros basin and compare them with the
other studies in the Tethys.
The Taleh Zang Formation is part of the lower
Paleogene (Upper Paleocene–Lower Eocene) succession
in the Lorestan zone of the Zagros basin, southwest of Iran
(Figure 1). The basin developed on the eastern continental
margin of Tethys during the Paleogene is a typical
Cenozoic carbonate platform on which alternating
carbonates and siliciclastics were deposited (James and
Wynd 1965; Murris 1980; Sengor 1990; Motiei 1995). This
study presents the changes in shallow-marine carbonate
settings in this part of Tethys during the noted period.
2. Geological setting
The Iranian plateau extends over a number of
continental fragments welded together. Each fragment
differs in its sedimentary sequence, nature and age of
magmatism and metamorphism, and also its structural
character and intensity of deformation (Berberian and
King 1981). These fragments are as follows: (1) Zagros
basin, (2) Sanandaj-Sirjan zone, (3) Urumieh-Dokhtar
volcanic arc, (4) Central Iran, (5) Alborz, (6) Kopeh
Dagh, (7) Lut block and (8) Makran (Figure 1a). The
Zagros Basin is the second largest basin in the Middle
East with an area of about 553,000 km2, which extends
Figure 1. Location map. (a) General map of Iran showing eight geologic provinces (Azizi and Moinevaziri 2008). (b) Subdivision ofZagros provinces (Sherkati and Letouzey 2004).
B. Bagherpour and M.R. Vaziri2
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from Turkey, northeastern Syria and northeastern Iraq
throughout northwestern Iran to southeastern Iran
(Hempton 1987).
Simply Folded Zagros, in which two studied sections
are located, is one of the three zones, namely the
Khuzestan Plain, the Simply Folded Zagros and the
Imbricated Thrust Zone (Motiei 1993). The Zagros fold–
thrust belt resulted from the continental collision between
the Arabian margin and the Eurasian plate following the
closure of the Neo-Tethys Ocean during the Cenozoic
(Stocklin 1968; Falcon 1974).
The Zagros fold–thrust belt is separated into several
zones (Figure 1b), which differ according to their
structural style and sedimentary history (Falcon 1961) –
Thrust Zone, Dezful Embayment, Izeh, Lorestan, Fars,
Abadan Plain, Bandar Abbas Hinterland and Complex
structure with metamorphic rocks. The study area (Maleh
kuh and Sarkan anticlines) is located in the Lorestan zone
of the Zagros basin (Figure 1b). According to Alavi (2007)
among the basement structures, the Khanaqin and
Bala-Rud fault systems bound the Lorestan salient to the
northwest and southeast. In the Lorestan Province (NE
Zagros), the detritic Amiran, Taleh Zang and Kashkan
formations were accumulated in a limited flexural basin in
response to the advancing thrust sheets (Homke et al.
2006).
3. Study areas and methodology
The study area is located southwest of the Khorramabad
and northeast of Pol-e-Dokhtar in the central part of the
Lorestan. Two sections were measured in details alongside
the northern flank of the Maleh kuh anticline at 478410 N
and 338100 E and northeastern flank of the Sarkan anticline
at 478500 N and 338170 E (Figure 2). The outcrop
thicknesses of the Taleh Zang Formation in these sections
are 122 metres at the Maleh kuh section and 120 metres at
the Sarkan section. Samples were collected from every
1.5 to 2 metres from (lithified) limestone beds, and 95
sampling horizons were studied as well. In case of
petrographical classification, Dunham classification
(Dunham 1962) has been used. Sedimentary structures
in the field observation have been used for sedimentary
environment interpretations.
4. Stratigraphy and age (Biostratigraphy)
The Taleh Zang Formation of Upper Paleocene–Middle
Eocene age is underlain conformably by Amiran Formation
and overlain by Kashkan Formation (Figure 3). This unit
has been deposited only in Lorestan with great changes in
thickness, facies and age. Amiran, Taleh Zang and Kashkan
Formations constitute a shallowing-upward depositional
sequence from deep-water siliciclastic to platform and
Figure 2. Geological map of the study areas in the Lorestan salient (after Alavi 2007).
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non-marine environments, respectively (Homke et al.
2009). According to Adabi et al. (2008), based on the larger
benthic foraminifera studied by Wynd (1965), the type
section of Taleh Zang Formation (which is located in the
western part of Lorestan) is Lower to Middle Eocene in age.
In the eastern part of Lorestan, where the Taleh Zang
Formation is a thin limestone unit underlain by Amiran
Formatin, fossil assemblage shows the Paleocene (Motiei
1993). In addition, Maghfori Moghaddam and Jalali (2004)
and Homke et al. (2009) established the Upper Paleocene
(Thanetian) for Taleh Zang Formation in the south and
southwest Khorramabad and Amiran anticline, respect-
ively. In the studied sections, benthic foraminifera such as
Orbitolites complanatus, Cuvillierina yarzai, Nummulites
globulus, Alveolina pasticillata, A. cf. avellana,
A. decipiens and A. lepidula strongly suggest an Early
Eocene age for the Maleh kuh section. Glomalveolina
primaeva, G. telemetensis, Periloculina sp., Lockhartia
diversa, Falotella alavensis, Stomatorbina binkhorsti,
Vania anatolica, Coskinon rajkae, Ranikothalia sindensis,
Sakesaria sp. in the lower part of Sarkan section and
Miscellanea iranica, Miscellanea miscella, Miscellanea
rhomboidea and Ranikothalia nuttalli in the upper part of
Sarkan section strongly suggest a Late Paleocene age for
the Sarkan section (Figure 4).
Taleh Zang Formation reveals a homogeneous
lithology. The investigated strata of the Paleocene Taleh
Zang Formation are composed of massive limestone,
medium-bedded limestone, marlstone and two conglom-
erate units. Algal and coral remains are abundant in
yellowish massive limestone at basal parts. Medium-
bedded limestone at middle parts consists of abundant
nummulitids. Conglomerate units are restricted to two
isolated occurrences (Figure 5). The investigated strata of
Eocene Taleh Zang Formation consist of massive lime-
stone, medium-bedded limestone and marlstone. Basal
Figure 3. Correlation chart of the Tertiary deposits of southwest Iran (adopted from Ala 1982), and simplified NE–SW stratigraphiccross-section across Lurestan Province from Kabir Kuh to the imbricate zone. The Sarkan and Maleh kuh stratigraphic columns are fromthis study (after Homke et al. 2009).
B. Bagherpour and M.R. Vaziri4
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part feature is cream limestone with a high percentage of
alvelolinids, which changes into nummulitid-bearing grey
limestone. The upper part of the investigated strata
consists of stromatolitic limestone and gastropod-bearing
limestone (Figure 6). Amiran Formation at both sections
consists of sandstone and sandy marlstone, while Adabi
et al. (2008) reported conglomerate of Amiran Formation
as lower boundary of Taleh Zang Formation at type
section. In addition, the upper boundary of Taleh Zang
Formation at Sarkan and Maleh kuh sections was defined
by red conglomerate and red siltstone of Kashkan
Formation, respectively.
Figure 4. Selected index species of both sections. (1) Alveolina decipiens, Schwager; magnification 20£ . (2) Alveolina pasticillata,Schwager; magnification £20. (3) Alveolina cf. avellana, Hottinger; magnification 20£ . (4) Alveolina vredenburgi, Davies and pinfold;magnification 20£ . (5) G. lepidula, (Schwager); magnification £40. (6) Cuvillierina yarzai, Ruiz de Gaona; magnification £40.(7) Fallotella alavensis, Mangin; magnification £20. (8) G. primaeva (Reichel); magnification £20. (9) Ranikothalia sindensis, Davies;magnification £16. (10) Miscellanea miscella (d’Archiac and Haime); magnification £40. (11) Lockhartia diversa, Smout; magnification£40. (12) Sakesaria sp.; magnification £40. (13) Ranikothalia nuttali, Davies; magnification £16. (14) Miscellanea rhomboidea, Kuss &Leppig; magnification £20 (pic 1 to 6 belong to Maleh kuh section and 7 to 14 belong to Sarkan section).
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5. Facies description and interpretation
The Taleh Zang Formation at the studied sections is
subdivided into 17 different microfacies (9 facies at the
Sarkan section and 10 at the Maleh kuh section; Table 1),
each characterised by a depositional texture, petrographic
analysis and foraminiferal assemblage. Based on paleoen-
vironmental and sedimentological analysis, four facies
belts can be recognised: tidal flat, lagoon, shoal and open
marine.
5.1 Lower Eocene facies
The following paragraphs discuss the identified facies,
arranged by their inferred depositional setting (shallow to
deep) at Lower Eocene Maleh kuh section.
5.1.1 Facies 1: stromatolitic boundstone
This facies is composed of mud supported lithology,
sometimes with fine sand to silt size quartz, and fine wavy
laminae without fossils. This facies occurs at the upper
part of the Maleh kuh section. Laminated stromatolites
Figure 5. Vertical facies distribution and sequences of theUpper Paleocene Taleh Zang Formation at the Sarkan Section.
Figure 6. Vertical facies distribution and sequences of theLower Eocene Taleh Zang Formation at the Maleh kuh section.
B. Bagherpour and M.R. Vaziri6
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Tab
le1
.S
um
mar
yo
fth
efa
cies
typ
esfo
rth
eM
aleh
ku
h(E
oce
ne)
and
Sar
kan
(Pal
eoce
ne)
sect
ion
s.
Fac
ies
Ag
eM
ain
com
po
nen
tS
tru
ctu
reE
nv
iro
nm
ent
1Stromatoliticboundstone
Eo
cen
eS
ilt
size
qu
artz
Wav
yla
min
aeT
idal
flat
-in
ner
ram
p2
Dolomudstone
Eo
cen
ean
dP
aleo
cen
eS
ilt
size
qu
artz
Th
inb
edd
ed,
bir
d’s
eye
stru
ctu
reT
idal
flat
-in
ner
ram
p
3Sandylimemudstone
Eo
cen
eS
ilt
size
qu
artz
Bir
d’s
eye
stru
ctu
reT
idal
flat
-in
ner
ram
p4
Limemudstone
Eo
cen
ean
dP
aleo
cen
eH
erri
ng
bo
ne
cro
ssb
edd
ing
Tid
alfl
at-i
nn
erra
mp
5Miliolidgastropodwackestone
Eo
cen
eD
asy
clad
acea
nal
gae
,g
astr
op
od
s,m
icri
tic
bio
clas
t,m
ilio
lid
sM
ediu
mb
edd
ed,
dar
kg
rey
Lag
oo
n-i
nn
erra
mp
6Alveolinid
Orbitolites
packstone–wackestone
Eo
cen
eP
elo
ids,
biv
alv
ean
dg
astr
op
od
,o
rbit
oli
tid
s,al
veo
lin
ids,
mil
ioli
ds
Th
ick
bed
ded
,cr
eam
colo
ure
dL
ago
on
-in
ner
ram
p
7Miliolidpeloidalgrainstone
Eo
cen
eM
ilio
lid
s,p
elo
ids,
Un
dif
fere
nti
ated
bio
clas
tsT
hic
kb
edd
ed,
crea
m,
com
pac
tL
ago
on
-in
ner
ram
p8
Alveolinabioclastic
grainstone
Eo
cen
eA
lveo
lin
ids,
intr
acla
sts,
mil
ioli
ds,
rota
liid
s,Nummulites,valvulinids
Th
ick
bed
ded
,w
hit
e,co
mp
act
Sh
oal
-in
ner
ram
p
9AlveolinaNummulites
packstone–grainstone
Eo
cen
eNummulites,alveolinids
Th
inb
edd
ed,
crea
mO
pen
mar
ine-
inn
erra
mp
10
Nummulitespackstone–wackestone
Eo
cen
eB
rok
enNummulites
Th
into
med
ium
bed
ded
Op
enm
arin
e-m
idd
lera
mp
11
Agglutinated-conical
foraminifera
glomalveolina
Pal
eoce
ne
Ag
glu
tin
ated
-co
nic
alfo
ram
inif
era,
glo
mal
veo
lin
ids,
laca
zin
ids,
mil
ioli
ds
Gre
y,
thic
kb
edd
edL
ago
on
-in
ner
ram
p
12
Glomalveolinabioclastpackstone
Pal
eoce
ne
Glo
mal
veo
lin
ids,
mil
ioli
ds,
rota
liid
s,n
um
mu
liti
ds,
red
alg
aean
dco
rals
,b
ival
ve
and
gas
tro
po
dG
rey
ish
crea
m,
thic
kb
edd
edL
ago
on
-in
ner
ram
p
13
Corallinealgalgrainstone
Pal
eoce
ne
Distichoplaxbiserialis,geniculate
corallinealgae,
miliolids,Peloids,quartzgrain
Wh
ite,
med
ium
bed
ded
inn
erra
mp
14
Foraminiferaalgalpackstone
Pal
eoce
ne
Nummulites,Miscellanea,Ranikothalia
Gre
yis
hcr
eam
,m
ediu
mb
edd
edF
ora
min
ifer
ash
oal
-in
ner
ram
p1
5Foraminiferapackstone
Pal
eoce
ne
Nummulites,Miscellanea,Ranikothalia
Gre
yis
hcr
eam
,m
ediu
mb
edd
edF
ora
min
ifer
ash
oal
-in
ner
ram
p1
6Coralgalboundstone
Pal
eoce
ne
scle
ract
inia
nco
ral,
Polystrata
alba,
no
n-g
enic
ula
teco
rall
ine
red
alg
ae,D.biserialis,
mil
ioli
ds
ort
ho
ph
rag
min
ids
Cre
am,
thic
kb
edd
edm
idd
lera
mp
17
Algalboundstone
Pal
eoce
ne
P.alba,M
esophyllum
,Lithothamnion,A
cervulina,D
.biserialis,bryozoans
Cre
am,
thic
kb
edd
edm
idd
lera
mp
Historical Biology 7
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structures are formed by the trapping and binding activities
of phototrophic microbes (Riding 1999). This facies type is
not only common in tidal flat sediments (Flugel 1982;
Hardie 1986; Lasemi 1995; Steinhauff and Walker 1996;
Hernandez-Romano 1999; Aguilera-Franco and Hernandez-
Romano 2004), and very common in the intertidal zone, but
also in supratidal and shallow subtidal environments (Flugel
2004). Also, the fine-sized quartz grains in this facies
suggest an environment close to coast (Figure 7a,b).
5.1.2 Facies 2: dolomudstone
This facies is characterised by yellow–brown, massive,
fine grain dolomite without any fossils or sign of fossils.
Bird’s eye structure and fine quartz grain sometimes are
visible. All dolomudstone samples were completely clear
of other sedimentary particles. Dolomudstone constitutes
the uppermost facies at the Maleh kuh section, also middle
and upper part of Sarkan section.
Due to fine grain crystals, lack of fossils, the presence
of bird’s eye structure and silt size quartz grains, this facies
was accumulated in low-energy tidal flat environment.
Mahboubi et al. (2001) assumed an upper intertidal
environment for the same facies (sandy dolomudstone).
This facies occurs in both sections (Figure 7c).
5.1.3 Facies 3 and 4: sandy lime mudstone and lime
mudstone
These facies are characterised by non-laminated, hom-
ogenous lime mudstone, lack of fossils and sometimes
bird’s eye structures. Facies 3 contains fine quartz grains
(10–15%) and occurs in both sections while facies 4
occurs at the upper part of the Maleh kuh section.
Unfossiliferous lime mudstone or fine-grained
dolomicrite sometimes with autogenetic evaporate
minerals occur in tidal flat and arid evaporitic coasts
(Flugel 2004). Detrital grains existence shows that facies
(a) (b)
(c) (d)
(e) (f)
Figure 7. (a) Facies 1: Stromatolitic boundstone. (b) macroscopic photo of Stromatolitic boundstone. (c) Facies 2: Dolomudstone. (d)microscopic photo of bird’s eye structures. (e) Facies 3: Sandy lime mudstone. (f) Facies 4: Lime mudstone. Scale bar: 1 mm.
B. Bagherpour and M.R. Vaziri8
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1, 2 and 3 are formed near the detrital grains source
(Figure 7d–f).
5.1.4 Facies 5: miliolid gastropod wackestone
This facies is characterised by wackestone texture and
contains dasycladacean algae and gastropods (15–20),
micritic bioclast (8–10%) and miliolids (25%). This facies
shows low diversity and high abundance of miliolids, and
occurs at the upper part of the Maleh kuh section.
The presence of mud matrix in this microfacies
indicates that deposition was mostly in a low- to moderate-
energy environment. The abundance of miliolids is
generally taken as evidence for restricted lagoonal and/or
relatively nutrient-rich back-reef environments (Geel
2000). Therefore, low diversity and high abundance of
miliolids indicate that this facies accumulated in a
nutrient-rich restricted lagoon environment. The presence
of the dasycladaleans suggests a very shallow marine
setting (Wray 1977). According to Rasser et al. (2005), the
association of the biogenic components suggests depo-
sition in a more restricted environment with a more
onshore position than the larger foraminiferal microfacies
types (Figure 8a).
5.1.5 Facies 6: Alveolinid Orbitolites packstone–
wackestone
The matrix is a fine-grained micrite. This facies consists of
foraminifera (50–55%), peloids (5–10%), bivalves and
gastropods fragment (5–10%). Orbitolitids comprises 15–
25%, alveolinids 50–60%, miliolids about 10%, valvuli-
nids, rotaliids and Nummulites each about 5% of the
benthic foraminifera assemblage in facies 6.
This facies occurs at the lower and middle parts of the
Maleh kuh section.
The presence of orbitolitids suggests a protected
shallow-water environment (Hottinger 1983). The pre-
sence of alveolinids and miliolids in a fine-grained matrix
confirms this interpretation. Rasser et al. (2005) inter-
preted that Alveolina orbitolitids facies has a lateral facies
of the Alveolina facies. Also inner-ramp settings are
characterised by alveolinid-dominated facies types, partly
with Orbitolites. Due to these statements and stratigraphic
position, facies 6 was deposited in shallow environment in
the inner-ramp settings (Figure 8b,c).
5.1.6 Facies 7: miliolid peloidal grainstone
The main feature of this sorted facies is the dominance of
small miliolids (30%) and peloids (30%) in a grainstone
texture. Undifferentiated small bioclasts (10%) are the
other components. This facies is characterised by low
diversity and limited foraminifera constituents and occurs
at the base of the Maleh kuh section.
The presence of miliolids and peloids suggests a
restricted environment, supported by low diversity. The
grainstone texture suggests a moderate- to high-energy
environment. According to Flugel (2004), this facies is
common in shallow platform interiors comprising
(a) (b)
(c) (d)
Figure 8. (a) Facies 5: Miliolid gastropod wackestone. (b) Facies 6: Alveolinid orbitolites packstone–wackestone. (c) Facies 6:Alveolinid orbitolites packstone–wackestone. (d) Facies 7: miliolid peloidal grainstone. Scale bar: 1 mm. M; Miliolid. GS; gastropod.AL; Alveolinids. OR; Orbitolites. RO; Rotaliid. B; Bioclast.
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protected shallow-marine environments with moderate
water circulation. This microfacies is interpreted as a
leeward shoal environment (Figure 8d).
5.1.7 Facies 8: Alveolina bioclastic grainstone
Of this facies, foraminifera account for 50%, intraclasts
account for 10% and ooids account for about 5%.
Foraminiferal assemblage contains alveolinids (50%),
miliolids (25%), rotaliids and Nummulites (each 10%),
valvulinids and orbitolitids (each 5%). Both abundance
and diversity are high. This facies occurs at the lower and
middle parts of the Maleh kuh section.
The well sorted and rounded grains and the absence of
fine-grained matrix indicate high-energy condition for the
deposition of Alveolina bioclastic grainstone. The
abundance of typical lagoonal fauna including alveolinids
and miliolids shows a leeward shoal position. Moreover,
this facies presents a transitional position between the
Alveolinid Orbitolites packstone–wackestone and the
Alveolina Nummulites packstone–grainstone. In accord-
ance with the standard microfacies types described by
Wilson (1975) and Flugel (1982), this facies is interpreted
as a shoal environment above the fair-weather wave base
(FWWB) which was located at the platform margin,
separating the open-marine from the more restricted
marine environments (Figure 9a,b).
5.1.8 Facies 9: Alveolina Nummulites packstone–
grainstone
This facies consists mainly of foraminifera and constitutes
70–80% of the rock volume. Foraminifera assemblage
shows an equal abundance of alveolinids (50%) and small
robust Nummulites (40%). Valvulinids, rotaliids, orbitoli-
tids and miliolids altogether constitute 10%. It is the most
diverse facies. This facies occurs at the lower and middle
parts of the Maleh kuh section.
(b)(a)
(c) (d)
(e) (f)
Figure 9. (a, b) Facies 8: Alveolina bioclastic grainstone. (c, d) Facies 9: Alveolina Nummulites packstone–grainstone. (e) Facies 10:Nummulites packstone–wackestone (Note to the fragmentation). (f) Facies 10: Nummulites wackestone. Scale bar: 1 mm.
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Alveolinids and nummulitids thrive in different
environments (Hohenegger et al. 1999); this facies reflects
an offshore transport of alveolinids into the Nummulites
facies. Alveolinids are probably derived from the
environments of the Alveolina bioclast grainstone.
Therefore, the association of normal marine fauna and
protected fauna indicates that deposition took place in the
more seaward position or according to Taheri et al. (2008)
in the open lagoon environment.
The texture suggests a high- to moderate-energy
condition. Also according to Hallock and Glenn (1986),
foraminifera build more robust shells in high-energy
environments. A higher diversity also suggests non-
restricted environment (Figure 9c,d).
5.1.9 Facies 10: Nummulites packstone–wackestone
Nummulites constitute 100% of the benthic foraminifera
in this facies and range from 15 to 50% of the rock volume;
the additional components are rare echinoderms. The
degree of fragmentation is high. This facies is character-
ised by a fine-grained matrix and occurs at the middle part
of the Maleh kuh section.
Proliferation of perforates benthic is indicative of
normal marine conditions (Geel 2000). Besides, according
to Hottinger (1997), nummulitids inhabit the deepest
paleoenvironments among the observed components.
The combination of micritic matrix and high degree of
fragmentation points to textural inversion (Folk 1962) that
can be explained by a low-energetic environment that was
subjected to occasional high-impact storms. They were
strong enough to cause fragmentation, but did not last long
enough to wash out the micritic groundmass. Therefore,
the Nummulites packstone–wackestone was deposited
below the FWWB (Figure 9e,f).
5.2 Upper Paleocene facies
Nine facies have been identified and arranged by their
inferred depositional setting (shallow to deep) at Upper
Paleocene Sarkan section. Dolomudstone and Sandy lime
mudstone are common both in Maleh kuh and in Sarkan
sections. For description and interpretation see facies 2 and
facies 3, which occur in Sarkan section, respectively.
5.2.1 Facies 11: Agglutinated-conical foraminifera
Glomalveolina wackestone
Mud and fine-grained micritic matrix are present and the
texture is characterised as a wackestone. Agglutinated-
conical foraminifera (especially Fallotella and Dictyoco-
nus) associated with glomalveolinids and lacazinids are
the main components (each about 30% of foraminiferal
assemblage) of this facies and contain 50% of the rock
volume and small rotaliids and small miliolids are less
abundant (10%). This facies occurs at the middle part of
the Sarkan section.
The agglutinated-conical foraminifera of the Paleo-
gene (Fallotella, Karsella, Daviesiconus, Dictyoconus,
etc.) have no ecological Neogene to recent counterparts.
But relying on other sedimentary sequences to interpret the
habitat of the conical foraminifera, such as the Adriatic
Platform (Hottinger and Drobne 1980), the position of
the conicals is clearly documented as the shallowest
association of larger foraminifera, below tidal level, in the
upper photic zone, at depths of less than 40 m (Vecchio
and Hottinger 2007). The presence of lime mud matrix
suggests low energy conditions, and the presence of
glomalveolinids and miliolids (imperforate porcellaneous)
suggests a shallow protected shelf. Also the stratigraphic
position confirms this interpretation (Figure 10a,b).
5.2.2 Facies 12: Glomalveolina bioclast packstone
This facies is characterised by a wackestone to packstone
texture and contains foraminifera (40-45%), red algae and
corals (5%), peloids (5%), bivalves and gastropods
fragments (10%). Dendritic coral (Oculina) rarely exists.
Foraminifera assemblage comprises glomalveolinids
(60%), miliolids (20%), small rotaliids (10%) and
nummulitids (10%).
Abundant occurrences of imperforate foraminifera
(including glomalveolinids) are interpreted as typical for
back-reef settings (Hottinger 1997). The presence of lime
mud peloids and gastropods supports this interpretation
(Figure 10c).
5.2.3 Facies 13: coralline algal grainstone
This facies is dominated by the fragments of Distichoplax
biserialis and geniculate coralline algae (10–15%), small
miliolids (10%), small rotaliids (5%) peloids (10–15%)
and quartz grain (10%) which is well sorted and has a
grainstone texture.
Grainstone texture, fragments of D. biserialis,
geniculate coralline algae and sorted components suggest
high-energy environment above FWWB. A similar
dominance of D. biserialis has been described from
Paleocene back-reef sediments from Oman (Racz 1979).
The combined occurrence of D. biserialis and quartz is
described from back-reef sediments from the Northern
Calcareous Alps (Moussavian 1984; Figure 10d).
5.2.4 Facies 14, 15: foraminifera algal packstone,
Foraminifera packstone
Facies 14 (Foraminifera algal packstone) is characterised
by the abundance of different types of hyaline perforate
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foraminifera (Nummulites, Miscellanea, Ranikothalia)
that constitute 60% of the rock volume and without
imperforate foraminifera. These fossils generally are small
to medium and thick shelled. Subordinate components,
coral and non-geniculate red algae (Lithothamnion)
fragments are larger than in the Coralline algal grainstone
and constitute 10% of the rock volume. In addition,
foraminifera are oriented parallel to bedding, the packing
degree is usually medium to high (especially in facies 15),
echinoderms and intraclasts sometimes are present
(Figure 10e,f). Facies 14 and 15 are different by the
absence of coral and red algae fragments and increase
of Nummulites in facies 15 (Foraminifera packstone;
Figure 10g,h). Facies 14 occurs at the lower and middle
parts of the Sarkan section, while facies 15 occurs at the
upper part of the Sarkan section.
The presence of hyaline perforate foraminifera and
larger size of non-geniculate red algae fragments suggest
seaward and deeper position than Coralline algal
grainstone for this facies. The grainy texture hints at
(a) (b)
(c) (d)
(e) (f)
(g) (h)
Figure 10. (a, b) Facies 13: agglutinated-conical foraminifera alveolina wackestone. (c) Facies 14: Alveolina bioclast packstone.(d) Facies 15: Coralline algal grainstone (XPL). (e, f) Facies 16: Foraminiferal algal packstone (Note algal and coral fragments). (g, h)Facies 17: Foraminifera packstone (Note parallel orientation). Scale bar: 1 mm. A; Agglutinated-conical foraminifera. L; Lacazinid. M;Miliolid. G; Glomalveolinid C; Coral. B; Bivalve. Ro; Rotaliid. D; Distichoplax biserialis. R; Non-geniculate coralline red algae.
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moderate- to high-energy environment and parallel
orientation to bedding supports this interpretation, since
according to Specht and Brenner (1979) and Aigner (1985)
this feature seems to have been formed by the winnowing
of wackestones and the removal of smaller particles. Also,
change from imperforated to perforated hyaline fauna
shows transition from protected environment to normal
marine environment. The absence of coral and algal debris
and higher abundance of perforated hyaline fauna in facies
15 indicate more seaward position than facies 14.
A similar facies type with abundant fragments of non-
geniculate and geniculate corallinaceans, Polystrata alba
and larger foraminifera is described as reef crest/back-reef
deposits by Baceta et al. (2005). Also Scheibner et al.
(2007) described a similar facies with geniculate
(fragments of D. biserialis), non-geniculate (Sporolithon,
Lithothamnion-type, P. alba) red algae and quartz grains
as sediments lie between the shallow intertidal to shallow-
subtidal rocky substrates of the coralline algal packstones
and the deeper reef-related microfacies types.
5.2.5 Facies 16: coralgal boundstone
The bulk of this facies consists of massive limestone. This
facies mainly consists of scleractinian coral colonies (50%
of the rock volume), which usually are encrusted by red
algae (P. alba, non-geniculate coralline red algae; 15–20%
of the rock volume). Small miliolids and orthophragminids
are present but never exceed 10% of the rock volume.
Macrofauna consists of bivalves and bryozoans in small
amounts. Large specimens of D. biserialis are present.
This facies is associated with the algal boundstone facies
and occurs in the lower part of the Sarkan section and has a
thickness of 14 m (Figure 11a,b).
A recent analogy for depth dependence of corals and
red algae is the Flower Garden Banks in the northwestern
Gulf of Mexico, where coralline algae are the dominant
sediment contributors below 50 m (Minnery 1990).
5.2.6 Facies 17: Algal boundstone
Algal boundstone is dominated by encrusting algae (P. alba
and coralline contain Mesophyllum, Lithothamnion; 25%),
which are associated with bryozoans and encrusting
foraminifera (Acervulina; 15%) and forms wavy crusts.
The diversity and abundance of larger benthic foraminifera
are very low. Fine-grained micritic matrix is present
and in addition, large and unfragmented specimens of
D. biserialis are abundant (10%; Figure 11c,d).
The colonial organisms in both facies suggest relatively
same facies belt for them. However, according to Baceta
et al. (2005), the dominance of red algae over corals is a
sign for a deeper water setting. According to Rasser (2000),
the presence of P. alba (in facies 16 and 17) and acervulinid
(a) (b)
(c) (d)
Figure 11. (a, b) Facies 18: Coralgal boundstone. (c, d) Facies 19: Algal bounstone, Scale bar: 1 mm. MT; Fine-grained micritic matrix.P; Polystrata alba. AC; Acervulinid. D; Distichoplax biserialis. R; Non-geniculate coralline red algae.
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(in facies 17) foraminifera suggests deposition in deeper
water than Coralline algal grainstone, Foraminifera algal
packstone and Foraminifera packstone for both types of
boundstone (facies16 and 17). The presence of micritic
matrix and unfragmented large specimens of D. biserialis
and non-geniculate coralline suggest a low-energy
environment, probably below FWWB.
5.3 Conglomerate unites
Conglomerate units are restricted to two isolated
occurrences. The thicknesses of these units are about 1.5
to 2 m. The main feature of these units is lateral
discontinuity and lenticular shape. The lower conglomer-
ate unit shows upward fining trend. The proportion of
carbonate increases upward and it becomes fossiliferous
(especially hyaline foraminifera) at the top. According
to lateral discontinuity, fining upward trend, unscathed
foraminifera and stratigraphic position, these units are
interpreted as submarine channels, which are probably
resulted from downslope transportation (Figure 12).
Moreover, according to Homke et al. (2009) towards
the top of the Taleh Zang Formation, one ,20-m-thick
shallow-marine siliciclastic unit occurs, which forms a
topographic high in the Amiran anticline. This unit is
composed of green-to-reddish sandstone and reddish
conglomerate with radiolarite pebbles.
As far as the source of the quartz grains is concerned,
however, it is hard to mention a distinct source for fine
grains in facies 3, wind can be the possible factor for
transportation. Regarding the coarse quartz grains in
Sarkan section, petrographic studies have shown that they
are mainly composed of radiolarite fragments of older
sedimentary rocks (Figure 12).
6. Paleoenvironmental model
6.1 Sarkan section
Based on the distribution of the foraminifera, lithology and
vertical facies relationships, the Upper Paleocene Taleh
Zang Formation at the Sarkan section shows different
settings from Early Eocene Taleh Zang Formation.
(a) (b)
(c)
(d)
Figure 12. Conglomerate unites (a, b) photomicrographs of the conglomerate, XPL and PPL, respectively. (c, d) Macroscopic photo ofConglomerate unites, Note lateral discontinuity, lenticular shape and upward fining trend.
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At the Sarkan section, four major environments can be
recognised. These environments are subdivided into nine
facies (Figure 13), which are mainly characterised
by Coralgal boundstone and Algal boundstone (facies
16–17) at the lower part of the section and great
abundance of larger foraminifera (facies 14–15) at the
upper part (Figure 5).
Tidal flat facies at the Sarkan, including Dolomudstone
and sandy lime mudstone (facies 2–3), are the same as
equivalent facies at the Maleh kuh section. Lagoon
environment (facies 11–12 & 13) is characterised by the
presence of porcellaneous and conical foraminifera with
wackestone to packstone texture and fragments of
D. biserialis plus geniculate coralline algae with
grainstone texture. Deepening trend within platform is
followed by Foraminifera algal packstone, Foraminifera
packstone (facies 14–15). Deepest facies at this section
includes two facies (facies 16–17) and is characterised by
the abundance of corals, algal communities and encrusting
organisms. Deepening trend is reflected by the changes
from grainstone rich in fragments of D. biserialis plus
geniculate coralline algae to facies with non-geniculate
coralline algae plus P. alba and facies with non-geniculate
coralline algae, P. alba and acervulinid foraminifera.
Figure 13. Depositional model for the Upper Paleocene platform carbonates of the Taleh Zang Formation at the Sarkan section.
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The decreasing abundance of geniculate corallines and the
increasing abundance of peyssonneliacean algae and –
especially – acervulinid foraminifera reflect a character-
istical deepening trend within platform (e.g. Reid and
Macintyre 1988; Perrin 1992; Rasser and Piller 1997;
Rasser 2000).
Facies changes show a depth gradient from shallower
to deeper environments with distribution of foraminifera
and other important components. Gradual facies changes
with an increase of water depth from inner ramp to middle
ramp environments and the absence of well-developed
margin and slope facies suggest a low gradient ramp.
From this point of view, inner ramp settings (above
FWWB) are represented by facies 1, 2, 11 to 14, also
middle ramp settings (below FWWB) are represented by
facies 16–17.
6.2 Maleh kuh section
Four major environments can be recognised in the Early
Eocene Taleh Zang Formation at the Maleh kuh section:
tidal flat, lagoon, shoal and open marine. These four
environments are subdivided into 10 facies (Figure 14).
The tidal flat (facies 1–4) environment is composed of
four facies, characterised by fine-grained matrix and lack
of fossil. The sediment in this environment is accumulated
in the inner ramp.
The lagoon environment (facies 5–6) mainly consists of
imperforate foraminifera including Orbitolites, alveolinids
Figure 14. Depositional model for the Lower Eocene platform carbonates of the Taleh Zang Formation at the Maleh kuh section.
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and miliolids and finer grain matrix. These facies indicate a
low energy, upper photic and shallow-restricted lagoon
depositional environment. Low diversity implies the
restricted environment.
The shoal environment (facies 7 to 9) consists of
perforated and imperforated foraminifera in a grainstone
texture. The environment reveals three different facies,
which are separable from each other by their fossil content.
Leeward shoal is characterised by miliolids and peloids in
a grainstone matrix. The characteristics of the highest
energetic part of the shoal are the rounded and sorted
bioclast and grainstone matrix. Towards the open marine,
perforated foraminifera and imperforated foraminifera
(small robust Nummulites) occur together. Two latter
facies represent high diversity, which implies non-
restricted environment.
The open marine environment is represented by facies
10. The main feature of the open marine environment is
the dominance of perforated and hyaline larger foramini-
fera (Nummulites). In addition, the texture shows a
transition from grainstone to packstone to wackestone.
On the basis of facies property and interpretation, the
transitions in the open marine facies show a deepening
trend. The diversity in facies 9 is diverse and comes very
low in the deepest facies (facies 10), which implies that the
diversity in this facies has been strongly controlled and
limited by ecological factors (e.g. light and oxygen).
The gradual transitions between the facies, the absence
of facies that shows high gradient (e.g. slump), lack of
evidence of re-sediment low-stand deposits and the
absence of reef facies indicate a low gradient carbonate
ramp (Figure 14).
Due to facies analysis and foraminifera paleoecology,
the inner ramp and higher portions of the middle ramp
environments are present in the Taleh Zang Formation at
the Maleh kuh section. Inner ramp settings (between upper
shoreface and FWWB) are represented by facies 1 to 9,
and middle ramp settings (between FWWB and storm-
wave base with sediment reworking by storms) are
represented by facies 10.
As a matter of focusing on the shallow environments, it
is difficult or impossible to state that this ramp is distally
steepened or homoclinal. These results are quite same as the
paleoenvironmental model presented by Adabi et al. (2008),
which assumed a carbonate ramp for Early Eocene Taleh
Zang at type section; however, they presented Assilina
wackestone as deepest facies and ooid grainstone as shoal
environment, both of them were absent in our study sections.
Living larger foraminifera are restricted to shallow,
well-lit sea floors (Hottinger 1983; Hallock 1984), and a
climatic belt limited by the 168C isotherm in the coldest
month (Langer and Hottinger 2000). Larger foraminifera
can maintain themselves only in oligotrophic environ-
ments because they are housing symbionts (Hallock 1985).
The dominance of larger foraminifera in all recognised
facies indicates deposition within warm water and
oligotrophic conditions in the euphotic zone.
7. Facies changes across Paleocene–Eocene
Studied sections of the Taleh Zang Formation show clear
changes in facies and biota from the Upper Paleocene
Sarkan section to Lower Eocene Maleh kuh section. Lower
part of the Sarkan section is dominated by red algae and
coral colony and facies with restricted environment
properties, while the upper part of the section is
characterised by facies with great abundance of larger
foraminifera (Ranikothalia, Miscellanea, Nummulites) and
the absence of coralgal associations and corals. Different
depth-dependant larger foraminifera (Orbitolites,
Alveolina and Nummulites) that are suitable components
for paleoenvironment reconstruction dominate the Maleh
kuh section deposits. Due to these important changes, it is
necessary to apply subdivision, and it is compared with
the other studied area. Figure 15a shows the Paleocene–
Eocene reconstruction of Zagros collision and foreland
basin and the position of the study area, which is located
below 208 paleolatitude. In addition, Figure 15b shows
previously studied regions (circles number 1–17) and
the area of present study, marked by a star. Scheibner and
Speijer (2008) subdivided the platform settings according
to the paleolatitudes and defined the platforms at middle
paleolatitudes (above 308), intermediate paleolatitudes
(208–308) and low paleolatitudes (below 208). Intermedi-
ate and low paleolatitudes are located at the southern rim
of the Tethys. Scheibner et al. (2005) presented a three-
fold platform subdivision in the southern Tethys (Galala
Mountains, Egypt; 208N paleolatitude) across the Paleo-
cene/Eocene boundary: Platform stage I (58.0–56.2 Ma;
Coralgal platform), Platform stage II (56.2–55.5 Ma;
coralgal and first larger foraminiferal platform), Platform
stage III (55.5–55.0? Ma; 2. larger foraminiferal plat-
form). Using this subdivision, Taleh Zang Formation
(which is located below 208N paleolatitude) at the lower
part of the Sarkan section is similar to Platform stage I, and
the upper part of the Sarkan section is similar to Platform
stage II. The Maleh kuh section is similar to Platform stage
III (Figures 5 and 6).
Two middle latitude successions at Pyrenees and
northwestern Aderiatic Carbonate Platform (AdCP) were
studied by Scheibner et al. (2005) and Zamagni et al.
(2008), respectively. Scheibner et al. (2005) found
persistent corals in the Pyrenees throughout the entire
period of study. This does not hold for Egypt, where
coralgal associations disappeared in the Uppermost
Paleocene (Shallow Benthic Zone 4; SBZ4). At this
time larger foraminifera became common in both regions,
with Assilina dominant in the Pyrenees (Assilina beds,
Baceta et al. 2005), Ranikothalia and Miscellanea
forming shoals in Egypt (Scheibner et al. 2003). Zamagni
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Figure 16. Biostratigraphy of the Taleh Zang Formation at the Maleh kuh section.
Figure 15. a. Paleocene–Eocene paleogeographic reconstruction of the Neo-Tethys area of Zagros collision and foreland basin (Heydari2008). Star shows location of the studied area. (b) Plate tectonic reconstruction of the Tethys (55 Ma) and locations of studied earlyPaleogene carbonate platforms, star shows the location of present study (Scheibner and Speijer 2008). T; Turkey. S; Sanandaj-Sirjan. L;Lut. AF; Afghanistan. ZFD; Zagros foredeep. I-P; India–Pakistan.
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et al. (2008) found small benthic foraminifera dominance
in the Upper Paleocene (SBZ3) facies and almost entirely
absent of corals except for rare and small patches.
In addition, according to Babic and Zupanic (1981),
Drobne et al. (1988), Jurkovsek et al. (1996), Turnsek and
Drobne (1998), Turnsek and Kosir (2004) and Vlahovic
et al. (2005) during this stage, coralgal reefs and abundant
larger foraminifera were reported from Northern Adriatic
Platforms. Common larger benthic foraminifera in the
benthic communities of the Uppermost Paleocene (SBZ
4), with Assilina and orthophragminids being the most
abundant forms are often associated with red calcareous
algae and corals. The Early Eocene in all studied regions
is dominant by different groups of depth-dependant larger
foraminifera and devoid of corals; however, according to
Baceta et al. (2005) and Scheibner et al. (2007) in sections
of Pyrenees coral-associated facies types occur subordi-
nately. Thus, the two middle-latitude carbonate platforms
(AdCP and Pyrenees) were more similar to each other.
In comparison with the abundance of Ranikothalia and
Miscellanea (except occurrence of Nummulites) and the
absence of corals and coralgal associations in Uppermost
Paleocene, the same is true for two low latitude carbonate
platforms (Taleh Zang Formation and Galala Mountains/
Egypt). Consequently, as Zamagni et al. (2008)
concluded, these similarities suggest latitudinal effect on
the evolution of shallow-water benthic communities.
To better understand biostratigraphic framework and the
importance of facies changes in Taleh Zang Formation,
distribution of identified foraminifera is plotted in front of
the studied sections (Figures 16 and 17). Thus, platform
stages I and II were formed in SBZ3 and SBZ4 at Sarkan
section, respectively, and platform stage III was formed in
SBZ 6–7 at Maleh kuh section.
In summary, the evolution from the first platform stage
(dominated by coral reefs) to the second transitional
platform stage (characterised by larger foraminifera in low
latitudes and coral reefs in middle latitudes) to the third
platform stage, which is dominated by larger foraminifera
in all latitudes, is strongly dependent on the organism
Figure 17. Biostratigraphy of the Taleh Zang Formation at the Sarkan section.
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distribution pattern of the two most important groups: corals
and larger foraminifera (Scheibner and Speijer 2008).
8. Conclusions
The Taleh Zang Formation represents sedimentation on a
carbonate ramp. Seventeen different microfacies were
recognised within the two studied sections (9 facies at the
Upper Paleocene Sarkan section and 10 at the Lower
Eocene Maleh kuh section), which are organised from
shallower to deeper parts.
The Upper Paleocene and Lower Eocene sediments are
characterised by well-pronounced changes from coralgal
and larger foraminifera shoal Paleocene facies to diverse
larger foraminifera Eocene facies. These changes are also
apparent in the other parts of the Tethys, particularly in
low latitudes (Egypt).
Acknowledgements
C. Scheibner, Jessica Z and S.J. Beavington-Penney are thankedfor critical reading of a previous version of this manuscript.Also A. Kheradmand is thanked for his kindly help to solvethe regional stratigraphy problems. We gratefully acknowledgeE. Heydari and H. Vaziri-Moghadam for critical comments onthe manuscript and M. Mirzaie for improving the English.
References
Adabi H, Zohdi A, Ghabeishavi A, Amiri-Bakhtiyar H. 2008.Applications of nummulitids and other larger benthic foraminiferain depositional environment and sequence stratigraphy: an examplefrom the Eocene deposits in Zagros Basin, SW Iran. Facies.54:499–512, doi:10.1007/s10347-008-0151-7.
Aguilera-Franco N, Hernandez-Romano U. 2004. Cenomanian–Turonianfacies succession in the Guerrero-Morelos Basin, Southern Mexico.Sediment Geol. 170:135–162.
Aigner T. 1985. Biofabrics as dynamic indicators in numrnuliteaccumulations. J Sediment Petrol. 55:131–134.
Ala MA. 1982. Chronology of bioclastic-corallinacean and migration ofhydrocarbons in Zagros sector of southwest Iran. Am Assoc Pet GeolBull. 66:1536–1542.
Alavi M. 2007. Structures of the Zagros Fold–Thrust belt in Iran. Am JSci. 307:1064–1095, doi:10.2475/09.2007.02.
Azizi H, Moinevaziri H. 2008. Review of the tectonic setting ofCretaceous to Quaternary volcanism in northwestern Iran. J Geodyn.47:167–179, doi:10.1016/j.jog.2008.12.002.
Babic L, Zupanic J. 1981. Various pore types in a Paleocene reef, Banja,Yugoslavia. In: Toomey DF, editor. European fossil reef models.SEPM Special Publication, vol. 30. Tulsa: SEPM. p. 473–482.
Baceta JI, Pujalte V, Bernaola G. 2005. Paleocene coralgal reefs of thewestern Pyrenean basin, northern Spain: new evidence supporting anearliest Paleogene recovery of reefal systems. PalaeogeogrPalaeoclimatol Palaeoecol. 224:117–143.
Bains S, Corfield RM, Norris RD. 1999. Mechanisms of climate warmingat the end of the Paleocene. Science. 285:724–727.
Berberian M, King GCP. 1981. Towards a palaeogeography and tectonicof Iran. Can J Earth Sci. 18:210–265.
Bralower TJ. 2002. Evidence of surface water oligotrophy during thePaleocene–Eocene thermal maximum: nannofossil assemblage datafrom the Ocean Drilling Program Site 690, Maud Rise, Weddell Sea.Paleoceanography. 17:1023, doi:10.1029/2001PA000662.
Bralower TJ, Thomas E, Zachos JC. 1995. Late Paleocene to Eocenepaleoceanography of the equatorial Pacific Ocean: stable isotopes
recorded at Ocean Drilling Program Site 865. Allison GuyotPaleoceanogr. 19:841–865.
Crouch EM, Heilmann-Clausen C, Brinkhuis H, Morgans HEG, RogersKM, Egger H, Schmitz B. 2001. Global dinoflagellate eventassociated with the Late Paleocene thermal maximum. Geology.29:315–318.
Dickens GR. 2000. Methane oxidation during the Late Palaecoenethermal maximum. Bull Soc Geol Fr. 171:37–49.
Dickens GR, O’Neil JR, Rea DK, Owen RM. 1995. Dissociation ofoceanic methane hydrate as a cause of the carbon isotope excursionat the end of the Paleocene. Paleoceanography. 10:965–971.
Drobne K, Ogorelec B, Plenicar M, Zucchi-Stolfa ML, Turnsek D. 1988.Maastrichtian, Danian and Thanetian beds in Dolenja Vas (NWDinarides, Yugoslavia). Mikrofacies, foraminifers, rudists andcorals. Razprave. 29:147–224.
Dunham RJ. 1962. Classification of carbonate rocks according todepositional texture. Am Assoc Pet Geol Mem. 1:108–121.
Falcon NL. 1961. Major earth-flexturing in the Zagros Mountain ofsouthwest Iran. J Geol Soc Lond. 117:367–376.
Falcon NL. 1974. Southern Iran: Zagros Mountains. In: Spencer A, editor.Mesozoic–Cenozoic Orogenic Belts. London: Geological Society ofLondon, Special Publications, vol. 4. p. 199–211.
Flugel E. 1982. Microfacies analysis of limestone. New York: Springer.p. 633.
Flugel E. 2004. Microfacies analysis of limestone: analysis, interpretationand application. Berlin: Springer. p. 976.
Folk RL. 1962. Spectral subdivision of limestone types. In: HamWE, editor. Classification of carbonate rocks. AAPG Memoir, 1.p. 62–84.
Galeotti S, Kaminski M, Coccioni R, Speijer R. 2004. High-resolutiondeep-water agglutinated foraminiferal record across the Paleocene/Eocene transition in the Contessa Road Section (central Italy). In:Bubık M, Kaminski MA, editors. Proceedings of the SixthInternational Workshop on Agglutinated Foraminifera. GrzybowskiFoundation Special Publication, 8. p. 83–103.
Geel T. 2000. Recognition of stratigraphic sequences in carbonateplatform and slope deposits: empirical models based on microfaciesanalysis of Palaeogene deposits in southeastern Spain. PalaeogeogrPalaeoclimatol Palaeoecol. 155:211–238, doi:10.1016/S0031-0182(99)00117-0.
Hallock P. 1984. Distribution of larger foraminiferal assemblages on twoPacific coral reefs. J Foramin Res. 14:250–261.
Hallock P. 1985. Why are larger Foraminifera large? Paleobiology.11:195–208.
Hallock P, Glenn EC. 1986. Larger foraminifera: a tool forpaleoenvironmental analysis of Cenozoic depositional facies.Palaios. 1:55–64.
Hardie LA. 1986. Ancient carbonate tidal flat deposits. Colorado SchoolMines Quart. 81:37–57.
Hempton MR. 1987. Constraints on Arabian plate motion and extensionalhistory of the Red Sea. Tectonics. 6:687–705.
Hernandez-Romano U. 1999. Facies stratigraphy and diagenesis of theCenomanian–Turonian of the Guerrero-Morelos platform, southernMexico: reading, postgraduate research institute for sedimentology[PhD thesis]. [UK]: University of Reading. p. 322
Heydari E. 2008. Tectonics versus eustatic control on supersequences ofthe Zagros Mountains of Iran. Tectonophysics. 451:56–70.
Hohenegger J, Yordanova E, Nakano Y, Tatzreiter F. 1999. Habitats oflarger foraminifera on the reef slope of Sesoko Island, Okinawa,Japan. Mar Micropaleontol. 36:109–168. doi:10.1016/S0377-8398(98)00030-9.
Homke S, Verges J, Serra-Kiel J, Bernaola G, Garces M, Verdu IM,Karpuz R, Sharp I, Goodarzi MH. 2006. Cenezoic evolution of theearly Zagros foreland basin in the Lurestan Province (NE Zagros).Insights from biostratigraphy of the Amiran-Kashkan detriticsequence and new fission tracks dating. Geophysical ResearchAbstracts. Vol. 8,07800.
Homke S, Verges J, Serra-Kiel J, Bernaola G, Sharp I, Garces M,Montero-Verdu I, Karpuz R, Goodarzi MH. 2009. Late Cretaceous-Paleocene formation of the proto-Zagros foreland basin, LurestanProvince, SW Iran. Geol Soc Am Bull. 121(7–8):963–978.
B. Bagherpour and M.R. Vaziri20
Downloaded By: [Bagherpour, Borhan] At: 08:29 10 June 2011
Hottinger L. 1983. Processes determining the distribution oflarger foraminifera in space and time. Utrecht Micropal Bull.30:239–253.
Hottinger L. 1997. Shallow benthic foraminiferal assemblages as signalsfor depth of their deposition and their limitations. Bulletin de laSociete Geologique de France. 168:491–505.
Hottinger L, Drobne K. 1980. Early Tertiary conical imperforateforaminifera. Razprave, Slovenska Akademia Znanosti in Umet-nostni (Ljubljiana). 22:186–276.
James GA, Wynd JG. 1965. Stratigraphic nomenclature of Iranian oilconsortium agreement area. Am Assoc Pet Geol Bull. 49:2182–2245.
Jurkovsek B, Toman M, Ogorelec B, Sribar L, Drobne K, Poljak M,Sribar L. 1996. Geological Map of the Southern Part of the Trieste-Komen Plateau. Institut za geologijo, geotehniko in geofiziko,Ljubljana. p. 1–143
Katz ME, Pak DK, Dickens GR, Miller KG. 1999. The source and fate ofmassive carbon input during the latest Paleocene thermal maximum.Science. 286:1531–1533.
Kelly DC. 2002. Response of Antarctic (ODP Site 690) planktonicforaminifera to the Paleocene–Eocene thermal maximum: faunalevidence for ocean/climate change. Paleoceanography. 17:1071,doi:10.1029/2002PA000761.
Kennett JP, Stott LD. 1991. Abrupt deep-sea warming, paleoceano-graphic changes and benthic extinctions at the end of the Palaeocene.Nature. 353:225–229.
Koch PL, Zachos JC, Gingerich P. 1992. Correlation between isotoperecords in marine and continental carbon reservoirs near thePalaeocene/Eocene boundary. Nature. 358:319–322.
Langer MR, Hottinger L. 2000. Biogeography of selected ‘larger’foraminifera. Micropaleontology. 46(Suppl. 1):105–127.
Lasemi Y. 1995. Platform carbonates of the Upper Jurassic MozduranFormation in the Kopet Dagh Basin, NE Iran-facies, palaeoenviron-ments and sequences. Sediment Geol. 99:151–164.
Macleod N, Ortiz N, Fefferman N, Clyde W, Schulter C, MacLean J.2002. Phenotypic response of foraminifera to episodes of globalenvironmental change. In: Culver SJ, Rawson P, editors. BioticResponse to Global Change. Cambridge: Cambridge University Press.p. 51–78.
Maghfori Moghaddam I, Jalali M. 2004. Stratigraphy and paleoenviron-ment surveys of Taleh-Zang Formation in south and south west ofKhorramabad. J Sci Al-Zahra Univ. 17:34–46.
Mahboubi A, Moussavi-Harami R, Lasemi Y, Brenner LR. 2001.Sequence stratigraphy and sea level history of the Upper Paleocenestrata in the Kopet-Dagh Basin, northeastern Iran. AAPG.85:839–859.
Minnery GA. 1990. Crustose coralline algae from the Flower GardenBanks, northwestern Gulf of Mexico: controls on distribution andgrowth morphology. J Sediment Petrol. 60:992–1007.
Motiei H. 1993. Stratigraphy of Zagros. In: Treatise of geology of Iran.Tehran: Iran Geological Survey Publication, 1: 281–289.
Motiei H. 1995. Petroleum geology of Zagros. Tehran: Geological Surveyof Iran. 1009 pp.
Moussavian E. 1984. Die Gosau-und Alttertiar-Gerolle der Angerberg-Schichten (Hoheres Oligozan, Unterinntal, Nordliche Kalkalpen).Facies. 10:1–86.
Murris RJ. 1980. Middle East: stratigraphic evolution and oil habitat.Am Assoc Petrol Geol Bull. 64:597–618.
Norris RD, Rohl U. 1999. Carbon cycling and chronology of climatewarming during the Palaeocene/Eocene transition. Nature. 401:775–778.
Perrin C. 1992. Signification Ecologique des foraminiferes acervulini-deset leur role dans la formation de facies recifaux et organogenesdepuis le Paleocene [Ecological significance of foraminiferaacervulinideset their role in the formation of biogenic reef faciesand from the Paleocene]. Geobios. 25:725–751.
Pujalte V, Payros A, Apellaniz E. 2009. Climate and biota of the EarlyPaleogene: recent advances and new perspectives. Geol Acta. 7:1–9,doi:10.1344/105.000000283.
Racz L. 1979. Paleocene carbonate development of Ras al Hamra. OmanBull Cent Rech Explor Prod Elf-Aquitaine. 3:767–779.
Rasser MW. 2000. Coralline red algal limestones of the Late Eocenealpine foreland basin in upper Austria: component analysis, faciesand palecology. Facies. 42:59–92.
Rasser MW, Piller WE. 1997. Depth distribution of calcareous encrustingassociations in the Northern Red Sea (Safaga, Egypt) and theirgeological implications. Proceedings of the 8th International CoralReef Symposium, p. 743–748.
Rasser MW, Scheibner C, Mutti M. 2005. A paleoenvironmental standardsection for Early Ilerdian tropical carbonate factories (Corbieres,France; Pyrenees, Spain). Facies. 51:217–232, doi:10.1007/s10347-005-0070-9.
Reid RP, Macintyre IG. 1988. Foraminiferal–algal nodules from theEastern Caribbean: growth history and implications on the value ofnodules as paleoenvironmental indicators. Palaios. 3:424–435.
Riding R. 1999. The term stromatolite: towards an essential definition.Lethaia. 32:321–330.
Rohl U, Bralower TJ, Norris RD, Wefer G. 2000. A new chronology forthe Late Paleocene Thermal Maximum and its environmentalimplications. Geology. 28:927–930.
Scheibner C, Rasser MW, Mutti M. 2007. The Campo section (Pyrenees,Spain) revised: implications for changing carbonate assemblagesacross the Paleocene–Eocene boundary. Palaeogeogr PalaeoclimatolPalaeoecol. 248:145–168.
Scheibner C, Reijmer JJG, Marzouk AM, Speijer RP, Kuss J. 2003. Fromplatform to basin: the evolution of a Paleocene carbonate margin(Eastern Desert, Egypt). Int J Earth Sci. 92:624–640.
Scheibner C, Speijer RP. 2008. Late Paleocene–Early Eocene Tethyancarbonate platform evolution – a response to long- and short-termpaleoclimatic change. Earth Sci Rev. 90:71–102, doi:10.1016/j.ears-cirev.2008.07.002.
Scheibner C, Speijer RP, Marzouk A. 2005. Larger foraminiferal turnoverduring the Paleocene/Eocene thermal maximum and paleoclimaticcontrol on the evolution of platform ecosystems. Geology. 33:493–496.
Sengor AMC. 1990. A new model for the Late Paleozoic–Mesozoictectonic evolution of Iran and implication for Oman. In: RoberstonAHF, Searl MP, Ries AC, editors. The geology and tectonics of theOman Region. London: Geological Society of London, SpecialPublication, 49. p. 797–831.
Sherkati S, Letouzey J. 2004. Variation of structural style and basinevolution in the central Zagros (Izeh zone and Dezful Embayment),Iran. Mar Pet Geol. 21:535–554.
Specht RW, Brenner RL. 1979. Storm-wave genesis of bioclasticcarbonates in Upper Jurassic epicontinental mudstones, East-centralWyoming. J Sediment Petrol. 49:1307–1322.
Steinhauff DM, Walker KR. 1996. Sequence stratigraphy of anapparently non-cyclic carbonate succession: recognizing subaerialexposure in a largely subtidal, Middle Ordovician stratigraphicsequence in eastern Tennessee. In: Witzke GA, Ludvingson JE, DayBJ, editors. Paleozoic sequence stratigraphy: views from the NorthAmerican Craton. Special Paper – Geological Society of America,306. p. 87–115.
Stocklin J. 1968. Structural history and tectonics of Iran: a review.Am Assoc Petrol Geol Bull. 52:1229–1258.
Taheri A, Vaziri-Moghaddam H, Seyrafian A. 2008. Relationshipsbetween foraminiferal assemblages and depositional sequences inJahrum Formation, Ardal area (Zagros Basin, SW Iran). Hist Biol.20(3):191–201.
Thomas E. 1998. Biogeography of the Late Paleocene benthicforaminiferal extinction. In: Aubry MP, Lucas S, Berggren WA,editors. Late Paleocene–Early Eocene Climatic and Biotic events inthe Marine and Terrestrial records. New York: Columbia UniversityPress. p. 214–243.
Turnsek D, Drobne K. 1998. Paleocene corals from the northern AdriaticPlatform. In: Hottinger L, Drobne K, editors. Paleogene ShallowBenthos of the Tethys 2. Dela-Opera SAZU 4. Razprave. Ljubljana:Slovenian Academy of Science and Arts. p. 129–154.
Turnsek D, Kosir A. 2004. Bacarella vipavica n. gen., n. sp. (Anthozoa,Scleractina) from reefal blocks in lower Eocene carbonate megabedsin the Vipava Valley (SW Slovenia). Razprave. 45:145–169.
Vecchio E, Hottinger L. 2007. Agglutinated conical foraminifera from theLower–Middle Eocene of the Trentinara Formation (southern Italy).Facies. 53:509–533, doi:10.1007/s10347-007-0112-6.
Historical Biology 21
Downloaded By: [Bagherpour, Borhan] At: 08:29 10 June 2011
Vlahovic I, Tisljar J, Velic I, Maticec D. 2005. Evolution of theAdriatic carbonate platform: palaeogeography, main events anddepositional dynamics. Palaegeogr Palaeoclimatol Palaeoecol. 220:333–360.
Wilson JL. 1975. Carbonate facies in geological history. Berlin: Springer.p. 471.
Wray JL. 1977. Calcareous algae. Amsterdam: Elsevier. p. 185.Wynd JG. 1965. Biofacies of Iranian Oil Consortium Agreement Area.
IOOC Rep 1082 (unpublished)Zamagni J, Mutti M, Kosir A. 2008. Evolution of shallow benthic
communities during the Late Paleocene–Earliest Eocene transitionin the Northern Tethys (SW Slovenia). Facies. 54:25–43.
B. Bagherpour and M.R. Vaziri22
Downloaded By: [Bagherpour, Borhan] At: 08:29 10 June 2011