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7
Synthesis & conclusion∗
Contents
7.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
7.2
Upper
7.2.1
7.2.2
7.2.3
7.3
The lithospheric structure of the Central Cyprus Arc . . . . . 168
7.4
Neogene evolution of central south
7.4.1 Pre-Miocene . . . . . . . .
7.4.2 Late Aquitanian . . . . . .
7.4.3 Late Burdigalian . . . . .
7.4.4 Late Serravalian . . . . . .
7.4.5 Late Tortonian . . . . . .
7.4.6 Messinian . . . . . . . . .
7.4.7 Early Pliocene . . . . . . .
7.5
Sinking
and
raising
the
southern
margin
of the Central Anatolian Plateau . . . . . . . . . . . . . . . 180
crust transect of the southern Anatolian
Infill relationships . . . . . . . . . . . .
Type of regional-scale structures . . .
Age of deformation . . . . . . . . . . .
Anatolian
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∗ To be modified and submitted to Earth Science Reviews as: D. Fernández-Blanco, G. Bertotti,
and others, An integrated view linking the Central Cyprus Arc and the Central Anatolian Plateau
161
“Not everything that can be counted counts,
and not everything that counts can be counted.”
Albert Einstein
163
CAP Synthesis
Abstract
This Thesis documents the development of the southern margin of the Central
Anatolian Plateau and argues its vertical tectonic evolution to be the result of the
Anatolian crust reacting to major events happening in the Cyprus subduction
system. As the Cyprus slab retreated to its present-day position, the surface of the
Anatolian overriding crust subsided and stretched. Subsequent isostatic adjustments
led to regional surface uplift in the hinterland where the asthenosphere upwelled and
to large-wavelength platform subsidence in front of the trench where the lithosphere
settled. While the central segment of the Cyprus slab continued to accrete material
northward, slab tears on its sides induced tectonic activity along the Kırkkavak and
the Eçemis faults, which led to differential vertical histories in the southwest and
southeast segments of the margin. In the central segment, the combined growth
effects from the forearc basin system and continued accretion drove the thermal
expansion at the base of the Anatolian crust and induced large-scale ductile
deformation, which propelled the subsequent surface uplift of the modern Central
Taurus Mountains. The westward extrusion of the Anatolian-Aegean plate was
facilitated by the steepening and possible partial break-off of the Cyprian slab.
164
7.1
Chapter 7
Introduction
This Thesis argues that the Miocene to recent (down- and upward) vertical motions
that have occurred in south Turkey are controlled by the Cyprus subduction system.
The regional subsidence that led to marine deposition in a large area of the northeastern Mediterranean [e.g. Karabıyıkoğlu et al., 2000; Bassant et al., 2005; Boulton
and Robertson, 2007; McCay et al., 2013] has clearly been manifested regionally
since the Early Miocene [e.g. Flecker, 1995; Eriş et al., 2005]. The downward motion
was accommodated to a limited extent by regional-scale extensional faults during
basin initiation and in the absence of faulting afterward (Chapter 4). Deepening
and broadening of the basin took place during Middle and Late Miocene times [e.g.
Flecker, 1995; Walsh-Kennedy et al., 2014] (Chapters 3 and 5). Subsidence disruption occurred before Messinian times [e.g. Cosentino et al., 2012; Schildgen et al.,
2012b] when a broad surface uplift took place in present-day south Turkey, creating a
regional arc-shaped monocline [Çiner et al., 2008] in the absence of surface-reaching
thrusts, while contractional structures developed and subsidence continued in areas
immediately north and south of the growing topography (Chapters 3, 4 and 5).
This Thesis proposes that the vertical tectonic motions observed in the area result
primarily from the combined effects of (i) change in the subduction site to a close-topresent position [Robertson, 1998b] in south Cyprus, which led to the foundering of
a basin by large-wavelength suprasubduction platform subsidence [Cross and Pilger,
1978; Mitrovica et al., 1989; Gurnis, 1992; Stern and Holt, 1994](Chapter 4), and
(ii) accretion in the Central Cyprus arc (Chapter 5). This accretion controlled the
viscosity state of the Anatolian crust through the sedimentary load within, and the
thermal diffusion below its forearc region and resulted in a regionally warped surface
uplift by forearc high growth [Pavlis and Bruhn, 1983; Willett et al., 1993; Smit
et al., 2003](Chapter 6). The hypothesis explains the initial regional subsidence in
the northeastern Mediterranean area and the subsequent uplift in the Central Taurus
Mountains, as well as the correlative subsidence in the Cilicia Basin to the south of
the uplifted topography and the Tuz Gölü Basin to its north. This mechanism also
accounts for the regional shortening found in the area, as well as the type and overall
relative age of the regional-scale contractional structures: ranging from Pleistocene
and younger surface-outcropping thrust systems verging south in Cyprus, to a gently
south-dipping Late Miocene monocline and the absence of surface-breaking faults in
south Turkey.
To review, before the moment of subduction initiation in south Cyprus, as the
slab retreated southward, it replaced the asthenosphere in a large area of the northeastern Mediterranean, which led to regional isostatic subsidence by subcrustal loading and cooling. As the newly located subduction system evolved, the Cyprian
forearc basin system grew and eventually drove a viscosity drop at the base of the
Anatolian crust that led to ductile deformation and regional up warping in south
Turkey. In other words, the shortening exerted by the Cyprian subduction system
is expressed as brittle structures up- and seaward and as ductile deformation downand landward. This occurred in response to friction in the former case and to thermal weakening in the latter one. The previous chapters of this Thesis are hereon
integrated with other studies conducted in the area and time of interest to facilitate
the analysis and discussion of these hypotheses.
165
CAP Synthesis
Transect
4
Figure 7.1: Location of data presented in the discussion chapter. The
Morphobathymetry of the Mediterranean Sea [MediMap Group, 2005] is
used as a base map.
7.2
Upper crust transect of the southern Anatolian Plate
The results shown in this Thesis and those presented by other contributions in the
area are used in the construction of a regional transect of the upper crust that runs
south from the northern limit of the Mut Basin in south Turkey to the southern
limit of the Messaoria Basin in Cyprus. This regional transect, with an approximate
longitude of 310 km, runs N-S from Karaman city in the north to Nisou village in
the south. Under the regional point of view, four different tectonic regions can
be distinguished from north to south. These are (i) the southernmost part of the
continental basins of Central Turkey, with Tuz Gölü Basin as the main representative
in the high flat area of the Central Anatolian Plateau (CAP); (ii) the Tauride foldthrust belt and the Miocene Basins on top of it forming part of the south flank
of the CAP; (iii) the offshore Outer Cilicia Basin between Turkey and Cyprus as
the downward continuation of the south flank of the CAP; and (iv) the southwardthrusted Kyrenia Mountain Range and Circum-Troodos sedimentary succession.
Km
2
1
0
-1
-2
0
Km
20
-1
-3
Km
-2
-3
Km
-2
-1
Middle Miocene
Messinian
Figure 7.2: Upper crustal transect of SCAP and Cyprus, with double vertical exaggeration.
-1
Km
0
1
Lower Miocene
Pliocene
Quaternary
0
Km
1
2
0
Km
Pre-Cenozoic
1
-2
Km
2
0
-1
0
-1
Km
1
Km
2
1
0
-1
-2
166
Chapter 7
CAP Synthesis
7.2.1
167
Infill relationships
The basement – basin infill relationships are locally variable but regionally coherent
along the profile. Although the contact of the basin infill rocks with the basin
basement cannot be observed in the Cilicia Basin, it is traceable along the rest of the
profile, and two first-order observations can be made. The first observation is that
the infill rocks are unconformably overlying the basement. This is related to the fact
that the infill rocks are being deposited after partial regional peneplanation of basin
the basement rocks; they are doing so in relation to a large-scale subsidence event
that controlled the evolution of the area during the latest Oligocene-Early Miocene.
The second observation is that the infill rocks are, on the whole, continuous, or
show erosional terminations at the basin margins. Exceptions occur where postdepositional tectonic contacts disrupt this continuity, such as in the Kyrenia Range
and in the pinch out in the southern margin of the Messaoria Basin.
Starting with the Messinian deposits, the upper sector of the depositional sequence shows different relationships. Messinian rocks are nowhere seen in the north
of the section (onland Turkey). Instead, they are pinching out toward the northern
and southern boundaries of the Cilicia Basin and are showing a similar distribution
in the Messaoria Basin, with the peculiarity of their disruption by faults. This indicates that during Messinian deposition, onshore Turkey was above sea level, and the
Kyrenian Range was shaping a structural high probably still below sea level. This
fragmented distribution is also seen for the Plio-Q rocks along the profile. The PlioQ has relatively thin sequences that outcrop in the northernmost areas of the profile
and in the riverbeds in south Turkey. Thick sequences are seen in the Cilicia Basin,
and less relevant ones in the Messaoria Basin. Plio-Q rocks in these basins present
a clear asymmetry in relation to their bounding structural highs. In the case of the
Cilicia Basin, the Plio-Q depocenter is close to the Turkish shelf break-of-slope, indicating that subsidence in this area is related to the growth of the modern Central
Taurus Mountains.
7.2.2
Type of regional-scale structures
A range of structures varying in age, type, and geometry are seen along the profile.
When considering the regional-scale structures, contractional faults and folds are not
only clearly predominant, but also driving the development of most of the extensional
features.
The main first-order structures are (i) the thrust sheets verging north, responsible for the Kyrenia Range in north Cyprus and the asymmetry of the central
Cyprus Miocene basins, and (ii) the south-verging deep-rooted thrust system that
dominates deformation in the center of the Cilicia Basin. Hereon, this system is
referred to as “Central Cilicia backthrust system”. Both systems can be linked,
directly for the former and indirectly from the latter, to the Cyprus slab megathrust. The large-wavelength monocline in south Turkey - north Cilicia should be
included with these first-order structures, on the basis of its vertical offset, and the
overall wavelength observed along the transect with respect to the mentioned thrust
systems (∼45 km between the Kyrenia Range and the Central Cilicia backthrusts,
and a similar horizontal distance between the Central Cilicia backthrusts and the
regional monocline).
168
Chapter 7
The second-order features correspond with the most relevant extensional features observed along the transect, which appear basinward of the uplifted areas, i.e.,
northward of the Kyrenia Range and southward of the Central Taurus Range, as well
as the syntectonic wedges in the central areas of the Cilicia Basin. These systems are
“passive” recorders of the vertical displacements produced by the first-order features.
A clear example occurs in the south Cilicia Basin, where the displacements of the
north-dipping extensional faults are accommodated basinward in the weaker underlaying salts, by north-verging low-angle thrusts (i.e., a toe-slope system). The same
signal is observed in the northern sectors of the basin, where extensional systems
develop jointly with syntectonic wedges opening southward. These south-opening
wedges, which formed in relation to the growing topography in south Turkey, compete and partially overprint the minor north-opening wedges created by the Central
Cilicia backthrusts, which leads to the relevant thickening of the Plio-Q sequence in
this area.
The third-order structures that can be observed along the section are the normal
faults transecting the basal Miocene and basement rocks in the Mut and Messaoria
basins, which contributed to the initiation of subsidence in these areas. Many of
these features are partially overprinted by young or present-day strike-slip motions
that are difficult to estimate in the transect.
7.2.3
Age of deformation
The most relevant regional-scale structures show an age distribution that ranges from
present-day to pre-Messinian while moving north along the margin. In the south,
the south-verging thrusts set basement rocks on top of Miocene and Pliocene ones
and are either outcropping or being covered by Pleistocene or Quaternary deposits.
When moving north along the section, the extensional faults related with the toeslope system observed in the Cyprus shelf and shelf break-of-slope produce a clear
step-down bathymetry and their tilted blocks show growth sediments in the Middle
Pliocene. The Central Cilicia backthrust system produces bulges in the sea floor
and growth sediments at Middle Pliocene levels. Farther northward, the regional
monocline in south Turkey - north Cilicia is Late Miocene in age.
7.3
The lithospheric structure of the Central Cyprus Arc
The regional lithospheric-scale transect shown in Fig. 7.3 integrates geophysical data
from on- and offshore studies [Ates et al., 1999; Mart and Ryan, 2002; Stephenson
et al., 2004; Ergün et al., 2005; Koulakov and Sobolev, 2006; Özeren and Holt, 2010;
Mutlu and Karabulut, 2011; Bakırcı et al., 2012]. This lithospheric-scale transect
runs from the East Mediterranean to the CAP interior (650 km at around 33°30’
E) transecting from south to north: the Levantine Basin, the Cyprus arc trench,
Cyprus island, the Cilicia Basin, the Taurus Mountains and the Tuz Gölü Basin.
The subducting African lithosphere, located to the south of the transect is around
40 km thicker in its southern sector, where it is composed from a continental crustal
fragment corresponding to the Erastothenes Seamount. Farther north, in the area of
the subducting slab, it is formed by oceanic crust at depths in excess of 15 km and
deeper. An overall subduction angle of 45° is observed until around 60 km depth,
where ∼60° and steeper angles are reached as the slab deepens.
169
CAP Synthesis
Erastosthenes
Northeast Mediterranean
Trench
Cyprus
Cilicia Basin
Taurus Range
CVP
Turkey
Central Anatolia
0
20
20
40
40
60
60
Km
Km
0
80
100
Turkey
34º
East
Mediterranean
Continental crust
35º
36º
Oceanic crust
37º
Mantle Lithosphere
38º
~110km
No vertical exaggeration
39º
100
Asthenosphere
Figure 7.3: Lithospheric-scale section from Levantine to Central Anatolia
The Troodos Ophiolite is a sliver of oceanic crust trapped in between the African
and the Eurasian lithospheres. In the center-north and north of the transect, the
overriding Anatolian lithosphere varies from ∼110 km in the contact with the Cyprus
slab to ∼85 km at the northern tip of the transect, while an overall thickened continental crust also thins from ∼45 km in relation to the Taurus Mountains to ∼35 km
in Central Anatolia.
7.4
Neogene evolution of central south Anatolian Plate
We present a series of maps depicting the Neogene vertical evolution of the central
and southern areas of the CAP and north Cyprus that have been derived via regional
source-to-sink analysis. The maps depicted in figures 7.5 to 7.10 integrate data from
25 papers for the time and region of interest [Gürbüz and Kelling, 1993; Flecker, 1995;
Williams et al., 1995; Yetiş et al., 1995; Glover and Robertson, 1998a, b; Coskun,
2004; Karabıyıkoğlu et al., 2005; Aksu et al., 2005a, b; Bassant et al., 2005; Bridge
et al., 2005; Burton-Ferguson et al., 2005; Calon et al., 2005a, b; Eriş et al., 2005;
Hall et al., 2005a; Şafak et al., 2005; Ayyıldız, 2006; Monod et al., 2006; Derman
and Gürbüz, 2007; Özsayın and Dirik, 2007; Aydemir, 2008; Janson et al., 2010;
Özsayın and Dirik, 2011; Fernández-Blanco et al., 2013]. They also include our own
observations in the southwest and south-central areas (chapters 4 and 5) (Fig. 7.4).
We focus our attention on the development and position of source areas, and
their displacements through time, as well as the location of clastic sediment inputs
as a pass-through connecting the source areas with the zones of deposition. In this
regional source-to-sink approach, we have used sedimentary facies in the broad sense
described below:
Continental to transitional facies as terrigenous sediments, representing areas
near or on the source areas.
Shallow marine facies like reefal limestones, representing areas at sea-level depths,
where there is an absence of erosion and clastic deposition.
Deep sea facies that characterize areas with hemipelagic shales to turbidites deposits.
170
Chapter 7
The goal of this approach is not a detailed sediment facies reconstruction, thus
local details that may be relevant for other proposes are put aside in order to be
coherent with the scale of these regional source-to-sink evolutionary maps. Vertical
movements and main structures are depicted when relevance and confidence are
significant. White areas represent either the absence of a record or the absence of
deposition of the Neogene rocks.
Along with the source-to-sink maps, we present a 2D evolutionary model that
provides a N−S view of the center of the margin at earlier or roughly similar times.
This 2D tectonic evolution integrates the new findings reported in this Thesis with
previously published data [e.g. Robertson, 1998a, b; Harrison et al., 2004; Stephenson
et al., 2004; Calon et al., 2005a, b; McCay et al., 2013; McCay and Robertson, 2012].
5
Kιrşehir
1
14
Aksaray
Konya
11
4
Adana
Antalya
Mut
15
11
Based o :
. Fer á dez-Bla o et al.,
. Özsayi & Dirik,
,
. Turha Ayyildiz,
. Ayde ir & Ates,
. Bule t Cosku ,
. Der a & Gür üz,
. Gür üz & Kelli g,
. Willia s et al.,
. Aksu et al.,
;
Bridge et al.,
;
Hall et al.,
;
Burto -Ferguso et al.,
11
. Calo et al.,
. Yeiş et al.,
. Kara ıyıkoğlu et al.,
. This thesis hapter
. Glover & Ro ertso ,
. Fle ker,
. Mo od et al.,
. Basssa t et al.,
. Eris et al.,
. This thesis hapter
. Safak et al,
. Jaso ,
a,
Figure 7.4: Regional source-to-sink approach – Contributions
CAP Synthesis
7.4.1
171
Pre-Miocene
The N−S transect shows the situation in pre-Miocene times (Fig. 7.5-A). The transect depicts three areas above sea level; from north to south they are the Central
Taurus, the Kyrenia Range, and the Troodos Ophiolite. These three structural
highs stood above, but probably close to, a shallow sea, with water depths of less
than 1 km. The southernmost two structural highs are thought to be crustal scale
S-directed thrust systems that developed in relation with the subduction zone between the African and Anatolian plates, initiating the diffusive convergence zone
in the overriding plate [Calon et al., 2005b]. In the north, reactivation of growing
relief in the Central Taurus Mountains took place by Early Oligocene [e.g. Jaffey
and Robertson, 2005; Eriş et al., 2005], as shown by terrestrial sedimentation in
Oligocene to Early Miocene [e.g. Bassant et al., 2005; Şafak et al., 2005]. This continental deposition is broadly contemporaneous with the development of the Troodos
culmination and probably took place at the same time as the formation of the root
of the Kyrenia thrust system [McCay and Robertson, 2012] and the Cyprus arc
activation during the Early Miocene [e.g. Robertson, 2000; Stephenson et al., 2004].
7.4.2
Late Aquitanian
In the source-to-sink map of the Late Aquitanian times (Fig. 7.5-B), a transition from
a low-relief continent to a shallow sea is seen from the internal areas to the different
domains in the south (the Manavgat, Mut and Adana basins). From the hinterland
to the sea we observe continental and transitional deposits that reach as far south as
the present localities of Mut and Adana. The development of shallow water deposits,
free of terrigenous input, i.e., a carbonate platform, is seen between the internal
terrigenous continental and the external marine deposits observed in north Cyprus.
Regional subsidence led to the initial formation of a basin that eventually enclosed
an area extending at least from north of Mut to Messaoria (in the N−S direction).
In the hinterland further north, subaereal exposure and continental deposition was
taking place in the Tuz Gölü and related basins, although evidence of relief is not
known.
This represents a tectonically quiet situation in an area where palæotopography
seems to not affect the sedimentary distribution and a tectonically calm situation is
recorded, i.e., a gentle transition existed between the onland and the deeper basin.
The absence of canals and terrigenous pass-throughs point to neither important
production of sediments nor relevant sediment circulation toward the sea. The distribution of the deposits seems to indicate that the margin had an arcuate shape.
7.4.3
Late Burdigalian
As seen in the source-to-sink maps of the Late Burdigalian times (Fig. 7.6-A) the
internal area in the north (central Turkey) remains unchanged with continued continental sedimentation. In the southern areas, however, the onset of subsidence,
with the local contribution of basement faults, led to initial sea incursion and broadening of the basin. In between these areas, the re-establishment of relief growth
in the Taurus induces clastic sedimentation at the deformation front in the northwest and northeast areas (Manavgat and Adana basins), and the development of
172
Chapter 7
Troodos
V.e. x5
Kyrenia
culmination
S culmination
0
-2
?
A
N2
150 km
-4
Kms
50 km
B
Kι şehi
Aksa ay
Konya
Km
0
100
Co i e tal
to
t a siio al
Adana
Antalya
Shallo
ai e
Mut
He ipelagi
shales to
tu idites
Coa se te ige ous
i put
St esses
Uplit
20
24
A uita ia
Bu digalia
15
La ghia
10
Se a all.
To to ia
5
Messi .
0
Plio e e
Pleisto .
My
Su side e
Figure 7.5: Central Turkey to Central Cyprus: Late Aquitanian
palæo-draining systems sourcing northeast and northwest respectively, which shed
terrigenous to deeper areas of the basin, bypassing the carbonate shelf in some areas.
This is clearly the case of the Adana Basin, where the connections between continental and the deep marine deposits are readably traceable [Derman and Gürbüz,
2007]. These channels provide the evidence of the presence of the Taurus on the
northern margin of Adana by Late Burdigalian times. Similar relationships can be
inferred for the Antalya area as well, where palæo-draining systems with a source
toward the Taurus Mountains are seen.
The central domain (Mut Basin), located in between these two domains, records
a different situation in which an extensive carbonate platform develops. At some
localities, the platform takes place at the front of normal faults in contact with
the basement [Bassant et al., 2005; Janson et al., 2010]. Along the entire margin,
shallow water deposits reach considerable expansion and migrate toward the north.
The deposition of the deep-water shales and turbidites also migrates toward more
northern positions. This is an indication of sea incursion during this period.
173
CAP Synthesis
A
0m
30
25
20
15
10
5Ma
West Manavgat (Yaylaaran)
East Manavgat (Alarahan)
West Mut (Gezende)
-500
Center Mut (Mut-Sarikavak)
Oligocene
Lower
S
nian
inian
Torto
Mess
Serra
vallia
n
Middle
Upper
Miocene
Paleogene
2
Lang
hian
Burd
igalia
Aquit
anian
Chatt
ian
Rupe
tian
-1000
n
East Mut (Göksu Gorge-Erdemli)
N2
V.e. x5
0
Kms
-2
0
-2
?
50 km
-4
Kms
-4
250 km
SW
NE
Pre-Miocene
Basement
Lower Miocene
Erosive
contact
0 cm 20
Miocene continental rocks
Jurasic metamorphic
rocks
0
cm 40
0
SW
0
m
2
0
cm 40
NE
Sedimentary breccia
m
f
Metasediments
10
B
Gneiss
Kι şehi
�
� �
Aksa ay
Konya
�
�
�
�
�
�
� � �
� �
� �
�
�
� �
��
Km
0
100
Co i e tal
to
t a siio al
Adana
�
Antalya
�
�
�
Shallo
ai e
Mut
He ipelagi
shales to
tu idites
Coa se te ige ous
i put
St esses
Uplit
20
24
A uita ia
Bu digalia
15
La ghia
10
Se a all.
To to ia
5
Messi .
0
Plio e e
Pleisto .
My
Su side e
Figure 7.6: Central Turkey to Central Cyprus: Late Burdigalian
174
7.4.4
Chapter 7
Late Serravalian
The N−S transect shows the situation in Late Serravalian times (Fig. 7.7-A). Shallowing of the Outer Cilicia Basin took place in the back limb of the southern culminations, in which the crustal contraction was concentrated [Calon et al., 2005b]. These
culminations further developed but stood under sea level. To the north, platform
carbonates covered the remaining palæotopography.
In the source-to-sink maps (Fig. 7.7-B) we see that the central domain remains
unchanged, with sedimentation of continental deposits while probably undergoing
subsidence. However, there is an absence of deposition in several places within
the interior basins, which might be an indication that the area was functioning
as a source. The differentiation among the domains farther south, already seen
in Late Burdigalian times, is further accentuated by the Late Serravalian. In the
southern terrains, deeper water deposition is taking place in the southwest-southeast
domains, as well as in the Cilicia and Mesaoria basins in northern Cyprus, whereas
the south-center area remained at shallow-water conditions. This is an indication
that a widespread period of tectonic subsidence took place all over the southern
domains with the exception of the Mut area, which has reefal deposits that remained
at a higher position with respect to areas more to the south or those in the east and
west, thus recording a calmer shallow-water situation (chapter 4).
7.4.5
Late Tortonian
The N−S cross-section during Tortonian times shows an increase in shortening and
depicts the two S-verging crustal-scale linked thrust systems undergoing a strong
pulse of contraction (Fig. 7.8-A). This shortening concentrated mainly on the Kyrenia fold-thrust belt, but also influenced the Mut area. In addition, this is probably
the moment of the initial formation of the Outer Cilicia Basin backthrust system.
These thrust systems, and the deep-sourced deformation taking place in Mut area,
led to the division of the area into its present domains. In Late Tortonian times,
the growth and uplift of the Central and South Anatolia occurred [Schildgen et al.,
2012a; Cosentino et al., 2012; Fernández-Blanco et al., 2013] while subsidence continued in the Cilicia Basin.
Widespread shortening is also seen in the source-to-sink maps (Fig. 7.8-B). Shortening, which concentrated mainly in the southern areas, reached the present south
Turkey margin, as evidenced by smaller-scale fieldwork observations (chapter 4),
and as far north as the center of the system, where contractional features developed
in Late Tortonian [Fernández-Blanco et al., 2013]. Given the areal distribution of
the deposits in the southwest and southeast areas and knowing the area where no
deposition (erosion) takes place, a southward displacement of the thrust system behind these flank areas is inferred. The differentiation among map view domains is
now more pronounced. Mut remains at shallow water conditions, and the southwest and southeast areas, which in terms of vertical motions were evolving roughly
similarly to one another, undergo different evolutions. Relevant coarse terrigenous
inputs from the east-northeast in the Adana region are coeval with the uplift that
takes place in the west, in which continental terrigenous are being transported along
big distances in southwest and south directions while the overall Manavgat Basin
deposition occurs in deep environments. Northern Cyprus undergoes uplift.
175
CAP Synthesis
S
Miocene reefal rocks
N
S
N
A
Basement
0
2
km
0 km 5
2
S
N2
V.e. x5
0
Kms
-2
0
-2
?
50 km
-4
Kms
-4
250 km
Middle Miocene
N
S
0
m 100
S
0 km 1
B
N
S
N
S
Pre-Miocene
Basement
Lower Miocene
N
0
20 m
m
4
Kι şehi
�
� �
Aksa ay
Konya
�
�
�
�
� �
�
�
Antalya
�
� �
�
�
�
�
�
� �
Km
0
100
Co i e tal
to
t a siio al
Adana
Shallo
ai e
Mut
He ipelagi
shales to
tu idites
Coa se te ige ous
i put
St esses
Uplit
20
24
A uita ia
Bu digalia
15
La ghia
10
Se a all.
To to ia
5
Messi .
0
Plio e e
Pleisto .
My
Su side e
Figure 7.7: Central Turkey to Central Cyprus: Late Serravalian
176
Chapter 7
A
S.L.
Unit 3a
Top Tortonian
Tortonian
2
S
Middle Miocene
Pre-Miocene
Basement
Lower Miocene
V.e. x5
N2
0
0
-2
-2
?
?
-4
Kms
50 km
50 km
-4
Kms
NW
SE
045/06
Fpl = 252/52
210/12
55/15
175/20
10 m
5
155/4
0
170/2
NW
SE
?
��
?
Kι şehi
��
�
���
B
�
Aksa ay
Konya
�
�
�
�
�
15
La ghia
�
�
To to ia
�
�
� �
Coa se te ige ous
i put
�
� �
�
St esses
�
10
Se a all.
�
�
�
�
� � � � �
He ipelagi
shales to
tu idites
�
�
�
Bu digalia
�
� � � � � �
�
Shallo
ai e
�
�
�
� �
� �
�
�
�
� �
�
20
�
�
�
�
�
�
Mut�
A uita ia
100
Co i e tal
to
t a siio al
Adana �
�
��
�
24
Km
0
�
�
Antalya
�
�
�
��
�
Uplit
5
Messi .
0
Plio e e
Pleisto .
My
Su side e
Figure 7.8: Central Turkey to Central Cyprus: Late Tortonian
177
CAP Synthesis
A
NW
S
2
SE N
2
0
0
5km
-2
Km
0
2
S
km
10
-2
Mut Basin
20
30
40
Km
Cilicia Basin
50
60
V.e. x5
N2
0
0
-2
?
?
-2
?
-4
Kms
50 km
50 km
Messinian
Tortonian
Pre-Miocene
Basement
Lower Miocene
Middle Miocene
-4
Kms
SW
NE
Simplification of depth-converted line AKV 90603
�
�
�� �
�
�
��
�
�
eyli F
�
�
�
Ciha
Kι şehi
��
�
�
�
�
B
�
Aksa ay
Konya
�
�
�
� �
� �
��
Antalya
Km
0
100
Co i e tal
to
t a siio al
Adana
�
�
�
Mut
�
�
�
�
�
� � � � � �
�
�
�
�
�
�
Shallo
ai e
Ha de e F
�
He ipelagi
shales to
tu idites
�
Coa se te ige ous
i put
St esses
Uplit
20
24
A uita ia
Bu digalia
15
La ghia
10
Se a all.
To to ia
5
Messi .
0
Plio e e
Pleisto .
My
Su side e
Figure 7.9: Central Turkey to Central Cyprus: Basal Pliocene
178
Chapter 7
7.4.6
Messinian
The uplift of the southern margin of the Central Anatolian Plateau was effective by
Messinian times (Fig. 7.9). Continued margin growth and thrust activity confined
Messinian evaporites deposition to the Cilicia and limited sectors of the Messaoria
Basins [e.g. McCay, 2010] that were probably carried as piggyback basins in the
backlimb of the thrust sheets [Calon et al., 2005b]. Shallowing of the area forced the
initiation of slope instabilities and evaporates redeposition that created the toe-slope
fault system presently seen in north Cyprus offshore (chapter 5).
7.4.7
Early Pliocene
A situation that resembles present-day conditions is seen by the Early Pliocene
(Figs. 7.9, 7.10). Absence of deposition is observed in the Mut area, while continental
sediments started to deposit to the northern central domain, where re-establishment
of the limited extension took place, and to the sides of it in the Adana and Aksu
basins. The Early Pliocene is a period of relevant strain partitioning; shortening
is still active in the southern-central domains, but extensional events are recorded
northward. Roughly N-S shortening is manifested as transpressional structures in the
eastern domains and in the form of further development of compressional features,
which are still active in the center.
Thrust activity continues in the Kyrenia fold-thrust belt, where allochthonous
Pre-Cenozoic to Miocene sediments rest on top of Pliocene rocks and are in turn
truncated by the Pleistocene or Quaternary deposits [McCay et al., 2013] (Fig. 7.10).
The Outer Cilicia Basin backthrust system is active and develops contractional anticlines by Middle Pliocene, when the growth sediments are deposited. Deep-seated
deformation continues to develop the south margin of the Central Anatolian Plateau,
increasing the relative vertical motion differences between the Mut and the Cilicia
basins possibly until recent times.
2
S
N2
V.e. x5
0
-2
?
-4
Kms
?
?
-2
50 km
50 km
Plio-Q
Tortonian
Messinian
Middle Miocene
Pre-Miocene
Basement
Lower Miocene
S
N
Unit 3
Unit 1
Unit 3-4?
Unit 3b
5 km
Unit 3a
Unit 2
S
S
4
3
6
Unit 1
N
5
N
Plio-Q
2
Miocene
1
Unit 3b
5 km
Unit 3a
Unit 2
-4
Kms
5 km
Figure 7.10: Central Turkey to Central Cyprus: Present-Day
179
Pre-Miocene
CAP Synthesis
Troodos
V.e. x5
Kyrenia
culmination
S culmination
0
?
Lower Miocene
Troodos
Sculmination
Tortonian
Middle Miocene
150 km
Troodos
S culmination
V.e. x5
Kyrenia
culmination
-2
-4
Kms
50 km
V.e. x5
Kyrenia
culmination
N2
0
?
150 km
-2
-4
Kms
50 km
V.e. x5
Kyrenia
culmination
N2
0
-2
?
?
150 km
Messinian
N2
0
150 km
Ovgros
culmination
-2
-4
Kms
50 km
?
S
N2
-4
Kms
50 km
V.e. x5
S
N2
0
?
?
?
150 km
-2
-4
Kms
50 km
S
V.e. x5
N2
Plio-Q
0
?
?
?
-2
50 km
Plio-Q
Tortonian
Lower Miocene
Messinian
Middle Miocene
Pre-Miocene
Basement
Figure 7.11: Central Turkey to Central Cyprus: 2D upper crust evolution
-4
Kms
180
7.5
Chapter 7
Sinking and raising the southern margin
of the Central Anatolian Plateau
After partial peneplanation of the area, a broad regional subsidence, which started
in the latest Oligocene and widely developed by the Middle Miocene, took place
in a large area of the northeast Mediterranean in the absence of regional extensional faults. The Miocene basin that developed extended as far as, and possibly
beyond, the present locations of west Syria to the east [Boulton and Robertson,
2007; Devyatkin et al., 1997], west Turkey to the west [Karabıyıkoğlu et al., 2000],
central Turkey to the north [Fernández-Blanco et al., 2013], and central Cyprus to
the south [McCay et al., 2013]. The subsidence was only partially accommodated by
regional-extensional faults during the Early Miocene, and after this time no regional
structure is seen that is able to accommodate this downward motion. After this moment, and during the deposition of the lower sectors of the Middle Miocene rocks,
the last remnants of the pre-existing palæotopography were covered, as the regional
subsidence accompanied and largely controlled the sea-level inland incursion along
with the expansion of the carbonate platform. In Tortonian and younger times a
relevant set of regional-scale contractional structures developed in relation to the
shortening driven by accretion associated with the Central Cyprus arc. These structures are copious in Cyprus on the seaward side of the subduction system, where
they are represented as imbricated northward-verging thrusts. Some are as young as
present-day and they become older, less abundant, and more diffusive while moving
northward; they do so, first as a more spaced Mid-Pliocene backthrust system and
then further north as a broad Late Miocene monocline.
The observed tectonic evolution can be explained based on of the response of the
Anatolian crust to the evolution of the Cyprus subduction system. The Cyprus slab
retreated to its present-day position, leading to the crustal stretching and subsidence
observed in Early Miocene times. Associated with the retreat of the Cyprus slab,
variations in temperature and loading at subcrustal levels led to isostatic adjustments
that drive contrasting crustal motions. Regional uplift takes place in the interior
of the plateau, where the asthenosphere upwells, thus covering the space led by the
lithosphere. Large-wavelength platform subsidence occurs in the areas in front of the
trench where the lithosphere is now in areas formerly occupied by asthenosphere.
This led to the development and broadening of a large basin by Middle Miocene
times; infill deposits covered the Early Miocene palæotopography. Slab tears to the
east and west of the present central Cyprus margin, accommodated partly along
the Kırkkavak and the Eçemis faults, drove the differential vertical motions seen
along-strike in south Turkey, which caused contrasting depositional sequences in the
Manavgat, Mut and Adana basins. Coevally, the central sector of the subducting
lithosphere continues to accrete material into Anatolia. This accretion, in combination with the growth of the forearc basin system, forced a thermally induced viscosity
drop at the Anatolian basal crust, which facilitates large-scale ductile deformation
and subsequent surface uplift. The end result is the surface uplift of the modern
Central Taurus Mountains before Messinian times, which developed in south Turkey
a regional arc-shaped Miocene monocline in the absence of ground-breaking thrusts.
Final steepening of the Cyprian subducting slab and possible partial break-off contributed to the initiation of the westward extrusion of the Anatolian-Aegean plate
by latest Miocene times.