GeolCarp_Vol58_No3_197

GEOLOGICA CARPATHICA, JUNE 2007, 58, 3, 197—210

www.geologicacarpathica.sk

Introduction

Southeastern Anatolia is composed of the southeast Ana-
tolian Alpine orogenic segment (with E-W-oriented moun-
tain ranges) in the north and the Arabian Platform with its
low-lying plains to the south.

The southeast Anatolian orogenic belt has been divided

into three, approximately E-W trending, structural zones
(Yôlmaz 1993), which are from north to south: (1) a nappe
zone, comprising a Late Cretaceous ophiolitic suite and
metamorphic units of Paleozoic-early Mesozoic age; (2) an
imbricated zone, with imbricated thrust slices of Late Creta-
ceous—Early Miocene age; and (3) the Arabian Platform
(Southeast Anatolian Autochthon), comprising Early Cam-
brian to Middle Miocene marine sedimentary successions.
Southeast Anatolia underwent two major episodes: first, an
Alpine deformation with ophiolite emplacement onto the
Arabian Platform in the Late Cretaceous; and second, a col-
lision between the northern nappes and the Arabian Plate
during the Middle Eocene—Miocene interval. The latter
event caused the amalgamation of different tectonic units,
namely ophiolitic, metamorphic and volcano-sedimentary
sequences (e.g. engör & Yôlmaz 1981; Yôlmaz 1993).

Origin and evolution of the Southeast Anatolian

Metamorphic Complex (Turkey)

ÖMER BOZKAYA

, HÜSEYùN YALÇIN

, ZEYNEL BA IBÜYÜK

OLCAY ÖZFIRAT

and HÜSEYùN YILMAZ

Cumhuriyet University, Department of Geological Engineering, 58140 Sivas, Turkey; bozkaya@cumhuriyet.edu.tr

Cumhuriyet University, Graduate School of Natural and Applied Sciences, 58140 Sivas, Turkey

Cumhuriyet University, Department of Geophysical Engineering, 58140 Sivas, Turkey

(Manuscript received November 8, 2005; accepted in revised form December 7, 2006)

Abstract: The Southeast Anatolian Metamorphic Complex comprises three structural units, the Keban, Malatya and
Pütürge-Bitlis Metamorphics. Of these, the Keban Metamorphics (Carboniferous-Triassic) mainly comprise metamor-
phosed limestones/marbles and phyllites, consisting mainly of calcite, dolomite, quartz, albite, phyllosilicates (kaolinite,
2M

white K-mica, 1M biotite, IIb chlorite, C-S, C-V and I-S) and scarce tremolite/actinolite and biotite, which were

metamorphosed under sub-greenschist- to greenschist-facies conditions. The Malatya Metamorphics (Carboniferous-Trias-
sic) comprise mainly metacarbonate rocks and metapelites – made up of calcite, quartz, albite, phyllosilicates (anchizonal-
epizonal 2M

white K-mica and paragonite, IIb chlorite, dickite, C-V, C-S, I-S), chloritoid and goethite – that underwent

a sub-greenschist-facies metamorphic event. The Pütürge Metamorphics (Precambrian-Permian) comprise metamorphic
lithologies of pre-Devonian high-grade (augen gneiss, amphibolite, mica schist/gneiss, granitic gneiss) and post-Carbon-
iferous low-grade rocks (calc-schist/marble and schist). The high-grade parts of this metamorphic unit display a Barrovian-
type prograde metamorphism at amphibolite facies. Retrograde mineral occurrences, such as chlorite, C-V and C-S from
garnet and biotite, reflect post-metamorphic-peak cooling assemblages. Low-grade parts of this unit are made up of calcite,
dolomite, albite, phyllosilicates (IIb chlorite, 2M

muscovite and 1M biotite, C-S), reflecting greenschist-facies metamor-

phic conditions. Lithological and mineralogical characteristics of the Southeast Anatolian Metamorphic Complex imply the
following: the Keban Metamorphics are similar to the Eastern Taurus Autochthon (Geyikdaûô Unit) and apparently
originated from that unit. In spite of their similar age ranges, the Malatya Metamorphics are quite different from the Keban
Metamorphics and were probably derived from northern allochthonous Tauride units (e.g. Aladaû Unit). The Pütürge
Metamorphics originated from a southern source (i.e. the Arabian Platform), and horizons of similar age differ from those
of the Keban and Malatya Metamorphics.

Key words: X-ray powder diffraction, low-grade metamorphism, petrography, crystallinity, polytype, b

value,

organic-matter reflectance, phyllosilicate.

The Southeast Anatolian Metamorphic Complex

(SAMC) comprises the main Alpine terranes of the Taurides
and the Arabian Plate. The origin and evolution of this
complex are important insofar as information collected from
it allow reinterpretation of the regional geodynamic scenar-
io, especially concerning the various stages of the Alpine
orogeny. Even though these metamorphic rocks carry some
clear fingerprints reflecting stratigraphic and mineralogical-
petrographical characteristics, there are still various hypoth-
eses – principally two – concerning their origins. In the
first hypothesis, the Malatya and Keban Metamorphics rep-
resent the Tauride Platform, whereas the Pütürge and Bitlis
Metamorphics represent the Arabian Platform (Yazgan
1984; Göncüoûlu & Turhan 1984; Yazgan & Chessex
1991). In the second hypothesis, all of the metamorphic
rocks of southeastern Anatolia belong to the Anatolian Plat-
form (Taurides) and display similar stratigraphic succes-
sions that were tectonically disrupted and fragmented
during the Late Cretaceous (Yôlmaz 1993).

The origin of the SAMC has, heretofore, not been defini-

tively determined because its stratigraphic-tectonic aspects
were only considered without detailed mineralogical-petro-
graphical studies. However, when the latter aspects are also

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BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

taken into account, striking conclusions can be reached
concerning the origin and tectono-metamorphic evolution
of very low- and low-grade metamorphic rocks, as shown
by the recent international literature (see e.g. Neubauer &
Sassi 1993; Sassi et al. 2004; Kisch et al. 2006; and refer-
ences therein), and by previous literature on the Tauride
Belt (Bozkaya & Yalçôn 2000, 2004a,b, 2005; Bozkaya et
al. 2002). Accordingly, in this paper, we aim to establish
the origin and evolution of the SAMC on the basis of de-
tailed textural and mineralogical properties, such as min-
eral associations, and the compositions, crystallinities,
polytypes and b

cell dimensions of phyllosilicate phases.

Geological setting

The northern boundary of the southeast Anatolian oro-

genic belt is surrounded by the units of the Tauride Belt,
an Alpine unit comprising tectonostratigraphic units
formed during the closure of the Neotethyan oceanic
branch in the eastern Mediterranean region ( engör & Yôl-
maz 1981; Göncüoûlu 1997). On the basis of their paleo-
geographical distributions, the Tauride nappes have been
tectonically classified by Özgül (1976) as north- (Bozkôr,
Bolkardaûô, Aladaû) and south- (Antalya and Alanya) de-
rived allochthonous units, and a central autochthonous
unit (Geyikdaûô) which has been overthrusted by the al-
lochthonous units (Fig. 1a).

The major units in the study area are (Fig. 1b): metamor-

phic rocks (the Keban, Malatya and Pütürge Metamor-
phics), the Baskil Magmatics, the Kömürhan Ophiolite
and the thick sedimentary successions of southeastern
Anatolia. The metamorphic rocks are, from north to south,
the Keban and Malatya Metamorphics, previously defined
as the Alanya Unit (Özgül 1976) and the Pütürge-Bitlis
Metamorphics, previously termed the Misis Unit (Özgül
1976) or Bitlis Zone (Göncüoûlu et al. 1997).

The Carboniferous-Triassic Keban Metamorphics, named

by Özgül (1976), crop out near the town of Keban and rep-
resent the northernmost metamorphic unit of the Taurides.
The northern edge of the Keban Metamorphics was tectoni-
cally overthrusted by Mesozoic carbonate rocks of the Mun-
zur Nappes, belonging to the Geyikdaûô Unit (Özgül &
Tur ucu 1984). Upper Cretaceous granitic and syenitic
rocks (i.e. the Baskil Magmatics) intruded the Keban Meta-
morphics along their southern margin (Fig. 1b). Tertiary
cover rocks overlie both the Keban Metamorphics and the
Baskil magmatic rocks. Although the boundary relations
between the Keban and Malatya Metamorphics are un-
known, it has been asserted that they have structural and
stratigraphic similarities (Yazgan 1984; Yôlmaz 1993; Yôl-
maz et al. 1993). Primary bedding planes of the Keban
Metamorphics are generally preserved and these rocks show
weak schistosity, whereas the Pütürge Metamorphics dis-
play well-defined schistosity. Furthermore, they are intense-
ly folded with NE-trending axes and high-angle dips
( > 45º), both related to a regional compressional regime.

The Malatya Metamorphics, Carboniferous—Triassic in age

(Karaman et al. 1993), have well-exposed tectonic-contact re-

lations with the Paleozoic Pütürge Metamorphics and the
Middle Eocene Maden Unit along their southern and eastern
margins – a result of southeastward thrusting. East of
Doûan ehir, chloritoid-bearing metapelitic rocks of the
Malatya Metamorphics have overthrusted staurolite-bearing
metapelitic rocks of the Pütürge Metamorphics. These rela-
tionships were interpreted as boundaries between lower and
upper metamorphic parts of the Malatya Metamorphics (Per-
inçek & Kozlu 1984; Yôlmaz 1993). Farther east, they also
overthrust the volcano-sedimentary rocks of the Maden Unit
(Fig. 1b). The northern and western boundaries of the meta-
morphics are unconformably overlain by Eocene and Mi-
ocene sedimentary cover units. On the other hand, the
Malatya Metamorphics contain abundant NE-SW-oriented
mesoscopic folds, indicating thrusting from NW to SE.

The Pütürge Metamorphics, of Precambrian-Permian

age, are depositionally overlain by the Maden Unit along
their northern edge, whereas they have thrusted bound-
aries with the Southeast Anatolian Autochthon and ophio-
lites along their southern and eastern contacts,
respectively (Fig. 1b). The metapelites have SW-NE-trend-
ing foliations and isoclinal folds with NE-trending axes,
reflecting early Alpine stages and a later deformational Al-
pine stage, respectively. Yazgan & Chessex (1991) point-
ed out that the first penetrative phase occurred prior to the
late Maastrichtian transgression in the Bitlis Massif; thus,
the main Alpine metamorphism of the Bitlis—Pütürge
Metamorphics may have been related to an ophiolite-ob-
duction event in the Campanian. After the Late Creta-
ceous, an extensional regime developed in the region, and
Middle Eocene sedimentary-volcanic rocks of the Maden
Unit were deposited onto the metamorphic and ophiolitic
rocks. The metamorphic rocks were thrust southeastward
onto Lower Miocene sedimentary units, reflecting the late
Alpine period. Therefore, a zone of imbrication developed
between the Southeast Anatolian Autochthon and the Bit-
lis Zone, comprising imbricated thrust slices emplaced
onto a Upper Cretaceous-Lower Miocene sequence.

The Baskil Magmatics (Asutay 1987) are exposed exten-

sively around Baskil and Elazôû; these rocks comprise pre-
dominantly plutonic (diorite, tonalite, granodiorite),
volcanic (basalt, andesite) and volcano-sedimentary (andes-
itic pyroclastic) rocks and granitic dykes.

The Kömürhan Ophiolite consists mainly of layered cu-

mulates, isotropic gabbros, a dyke complex and a volcanic
sequence (Beyarslan & Bingöl 2000), and was thrusted
onto the Maden Group and cut by granitic rocks of the
Baskil Magmatics.

Materials and methods

A total of 525 metapelitic- and metacarbonate-rock sam-

ples were collected from measured sections in the SAMC.
The samples were analysed by optical and X-ray powder
diffractometric (XRD) methods in the Department of Geo-
logical Engineering, Cumhuriyet University, Sivas.

The XRD analyses were performed on a Rigaku X-ray dif-

fractometer (type DMAX IIIC) with the following settings:

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BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

CuK , 35 kV, 15 mA, with slits (divergence= 1º, scatter =1º,
receiving = 0.15 mm, receiving-monochromator = 0.30 mm)
and scan speed of 1º2 /min. Semi-quantitative percentages
of whole-rock and clay-fraction samples (<2 µm) from the
metamorphic rocks were calculated using multi-component
mixtures with the external standard method of Brindley
(1980). Patterns of clay-fraction samples (with the samples
obtained using the sedimentation method) were acquired
under normal (air dried at 25 ºC for 16 hours), glycolated
(remained in a desiccator at 60 ºC for 16 hours) and heated
(heated at 490 ºC for 4 hours) conditions. Quartz was select-
ed as an internal standard for d-spacing measurements from
the clay minerals.

The width of the 1-nm illite and 0.7-nm chlorite peaks at

half-height (illite and chlorite ‘crystallinity’) were measured as

º2 based on the Kübler (Kübler 1968) and Árkai (Árkai

1991; Árkai et al. 1995) indices. The symbols KI and AI were
used for illite and chlorite ‘crystallinity’ as proposed by
Guggenheim et al. (2002). For the calibration of the crystallin-
ity measurements, the crystallinity index standards (CIS)
supplied by Warr & Rice (1994) were used. A linear regression
equation of KI

CIS

= 1.1565 KI

—0.0669 with R

= 0 .9894

was obtained. All crystallinity values are presented and plot-
ted as recalculated CIS values. Since the
1-nm illite peak for paragonite is broad-
ened asymmetrically towards high an-
gles (Frey 1987), KI values could not be
ascertained in samples containing this
mineral.

The b

cell dimensions – an empirical

indicator of pressure (Sassi & Scolari
1974; Guidotti & Sassi 1986; Rieder et
al. 1992) – were measured on d

060,331

—

re-

flections using the (211) peak of quartz
(2 = 59.97º, d = 0.1541 nm) as an internal
standard. For b

determinations, musco-

vite-rich samples with albite, but lacking
or containing only minor amounts of pa-
ragonite – that is, the Y assemblage in
the AKNa diagram of Guidotti & Sassi
(1976) – were evaluated.

Mica, chlorite and kaolin polytypes

were determined from diagnostic peaks
in non-oriented powder samples, as
suggested by Bailey (1988).

The chemical compositions of chlorites

were determined by XRD, a valid proce-
dure for chlorite chemistry (Nieto 1997).
Al values were determined from d

001

val-

ues, which were measured from d

005

re-

flections by using the formula of Brindley
(1961). Intensity ratios of the basal peaks
of I [ (002)+(004)] I [(001)+(003)], I (002)/
I(001) and I(004)/I(003) were used for
Fe

determinations (e.g. Brown & Brind-

ley 1980; Chagnon & Desjardins 1991).

For organic-matter reflectance (OMR)

measurements, organic matter was con-
centrated with HCl and HF acid treat-

ments, and then polished sections were prepared. OMR data
were obtained using a Leitz-Wetzlar MPV II-type micro-
scope, a 50 objective, a mercury lamp (CS 100 W-2), a
double B12 filter, a B38 heating-absorbing filter, a K510
barrier filter and a point counter at Hacettepe University,
Ankara. Sapphire (0.551 % R) and glass (1.23 % R) stan-
dards were used in calibration of the microscope, and mean
random reflectances (Rm

oil

%) were obtained using oil.

Petrography

Keban Metamorphics

This unit has four members – lower schist, lower marble,

upper schist and upper marble – as subdivided by Asutay
et al. (1986). In this study, we prefer the terms of metapelite
and metacarbonate to schist and marble insofar as the petro-
graphic determinations on these rocks indicate mainly slate,
phyllite and metalimestone and/or metadolomite (Fig. 2).

The lower metapelite member – the lowest part of the

Keban Metamorphics – comprises grey-black calc-phyl-
lite, phyllite and calc-schist intercalated with grey-black

Fig. 2. Vertical distributions of the lithology and mineralogical composition of the Keban
Metamorphics (Cal = calcite, Dol = dolomite, Qtz = quartz, Feld = feldspar, Kln = kaolin-
ite, M = K-mica, Chl = chlorite, I-S = mixed-layered illite-smectite, C-V = mixed layered
chlorite-vermiculite, Sm = smectite).

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ORIGIN OF THE SOUTHEAST ANATOLIAN METAMORPHIC COMPLEX (TURKEY)

metacarbonate rocks, and underwent widespread contact
metamorphism – with garnet zones along the margins of
syenitic intrusions. Calc-phyllite and scarce quartz-phyl-
lite show typical crenulation cleavage in the phyllosili-
cate-rich parts (Fig. 3a). Metacarbonate rocks include
metalimestone microlaminations (with microgranoblastic
texture) and marble (with typical granoblastic texture).
Elsewhere, they also contain garnet (andradite), tremolite,
albite and epidote, all due to contact metamorphism near
the syenitic intrusions.

The lower metacarbonate member comprises grey-black

recrystallized limestone and pink dolomites. Intra-dolomi-
crosparitic layers occur in the lowest levels, and also lo-
cally as matrix in the brecciated crystallized limestones.

The upper metapelite member disconformably overlies

the lower metacarbonate member; grey-brown metacon-
glomerates occur at its base, in which pebbles derived
from the underlying metacarbonate unit are elongated,
with their long axes parallel to the schistosity. Its main
lithologies are grey phyllite (calcite-epidote-albite-biotite

Fig. 3. Optical photomicrographs of textures and mineral assemblages in the SAMC (Cal = calcite, M = K-mica, OM = organic matter,
Cld = chloritoid, Qtz = quartz, Chl = chlorite, on = open nicol, cn = crossed nicol). a – Crenulation cleavage in the calc-phyllites of Keban
Metamorphics (KM-42, on), b – Thin organic matter layers orientated along the foliation planes in the crystallized limestones of Keban
Metamorphics (KM-36, on), c – Post-kinematic chloritoid porphyroblasts cutting the orientations of fine-grained white mica and chlorite
mass in the phyllites of Malatya Metamorphics (MM-50, on), d – Carbonate and crenulated phyllosilicate-rich level laminations in the im-
pure laminated marbles of the Malatya Metamorphics (ZB-183, cn), e – Recrystallized quartz and fine-grained albite-chlorite layers in the
chlorite-albite schist of Carboniferous-Permian parts of the Pütürge Metamorphics (MM-32, cn), f – Lepido-granoblastic texture in the
calcschist of Carboniferous-Permian parts of the Pütürge Metamorphics (PM-89, cn).

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BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

phyllite, calc-phyllite, albite-quartz phyllite, albite-mica-
chlorite phyllite, albite-muscovite phyllite) with grey-
green metabasic (epidote-albite-actinolite-chlorite schist)
rocks, grey-black metalimestone and scarce quartzite in-
terbeds. The phyllites are characterized by typical crenula-
tion cleavage. The metacarbonate levels locally include
thin phyllite microlaminations and may be classified as
metalimestone/marble with phyllite laminations. The me-
tabasic levels have a typical mineral paragenesis of
epidote + tremolite/actinolite + chlorite + albite ± biotite. In
addition, organic-matter-rich levels – up to 2—3 m in thick-
ness within the crystallized limestones and phyllites – are
characteristic of the upper levels of the unit (Fig. 3b). Such
occurrences have been noted within the Carboniferous-
Permian sedimentary rocks of the Eastern Taurus Autoch-
thon (Bozkaya & Yalçôn 2004b).

The upper metacarbonate member (i.e. the uppermost

unit of the Keban Metamorphics) consists of pink-white
recrystallized limestone, scarce claret red and brownish re-
crystallized dolomites and metamarls. Dolomite levels
(1 m) and thin-bedded metamarls are found in the middle
to upper levels of the unit. The recrystallized limestones
are characterized by microgranoblastic, partly stylolitic
and brecciated textures. Primary sedi-
mentary features, such as micrite-
sparite microlaminations and fossils,
are partially preserved in some of the
recrystallized limestones. The recrys-
tallized dolomites have finer-grained
crystals relative to the recrystallized
limestones.

Malatya Metamorphics

The Malatya Metamorphics were

studied south of Ye ilyurt and east of
Doûan ehir (Fig. 1b). This unit was
divided into lower (schist, calc-
schist) and upper (marble) metamor-
phic units. In this study, the Malatya
Metamorphics were investigated as
lower metapelites, slates partially
laminated with marbles, upper meta-
carbonates, and marble partially lami-
nated with slates (Yalçôn et al. 1999).

The main lithologies of the lower

metapelites, 750—1000 m thick, com-
prise greenish-brownish slates and yel-
lowish-brown slates laminated with
thin marbles and greenish metasand-
stones (Fig. 4). Chloritoid-bearing
phyllites and metasandstones – char-
acteristic lithologies along the thrust-
ed boundaries of the Malatya
Metamorphics – crop out east of
Doûan ehir in the thrust zone between
staurolite-bearing metapelites of the
Pütürge Metamorphics and metacar-
bonates of the Malatya Metamorphics

(Fig. 5). Chloritoid porphyroblasts are randomly oriented
by cutting sericite and chlorite planes in the schistose ma-
trix and, therefore, are of post-tectonic origin (Fig. 3c).
Slates and especially phyllitic slates in the upper parts of
this unit have well-developed crenulation cleavage (Kisch
1991; Guidotti et al. 2005), and also contain recrystallized
quartz lenses in the matrix of the fine-grained phyllosili-
cates (sericite and chlorite). The calcite and extremely low
dolomite contents of the slates increase up to 30 % upward,
due to 0.5—2-mm-thick metacarbonate laminations. These
rocks were termed slates with marble laminations, instead
of calc-schist, in the definitions of some earlier workers
(Karaman et al. 1993; Yôlmaz et al. 1993). Metapelitic rocks
are partially intercalated with metacarbonates (marble and
dolomitic marbles) and metaclastites (metasandstones
and metasiltstones). The albite and chlorite contents in-
crease in the metaclastic rocks, and quartz and albite
grains have sutured boundaries with fine-grained matrix.

The upper metacarbonates, ~ 700 m thick, comprise

thick-bedded, partially brecciated greyish to black-brown
marbles and dolomitic marbles (Fig. 4), including interca-
lations of slates, metasiltstones, metasandstones and
scarce metavolcanites. These rocks typically have grano-

Fig. 4. Vertical distributions of the lithology and mineralogical composition of the
Malatya Metamorphics (Dkt = dickite, Pg = paragonite, C-S = mixed-layered chlorite-
smectite. Other mineral abbreviations as in Fig. 2).

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ORIGIN OF THE SOUTHEAST ANATOLIAN METAMORPHIC COMPLEX (TURKEY)

blastic sutured textures, and contain crenulated slate lami-
nations (0.5—2 mm thick) in some levels, giving a schist-
like appearance (Fig. 3d). These rocks comprise marbles
with slate laminations, reflecting a primary sedimentary
feature (rather than the effects of metamorphic differentia-
tion) because of the low-metamorphic
grade. In addition, spherical and ellipsoi-
dal oolites/pisolites (0.5—15 mm) with
chlorite lamellae were noted in one slate
sample. These allochems are characteristic
of this unit; similar levels have also been
reported in the lowermost parts of the Per-
mian Aladaû Unit in the Aygörmez Daû
(Pônarba ô-Kayseri) area (Bozkaya &
Yalçôn 2004b). Metavolcanic rocks with
blastoporphyritic texture consist mainly of
plagioclase and scarce quartz, with an en-
tirely chloritic matrix.

Pütürge Metamorphics

These rocks were studied in the Pütürge

and Doûan ehir areas, wherein outcrops of
these lithologies are abundant. This unit
constitutes the relative basement of the two
areas, and comprises Precambrian-Devo-
nian high-grade metamorphic rocks (augen
gneisses, amphibolites, mica schist/gneiss-
es, granitic gneisses) in its lower parts and
Carboniferous-Permian low-grade meta-
morphic rocks (calc-schists/marbles and
schists) in its uppermost parts. This cover
unit, at least 500 m thick, is metamor-
phosed to greenschist facies and is similar
to weakly metamorphosed marbles of the
Bitlis Massif (Yazgan 1987).

Yellowish-white augen gneiss in the lower-

most parts of this unit has thick foliation with
cataclastic texture, and consists mainly of
quartz, plagioclase (partly myrmekitic), or-

Fig. 5. Cross-section of overthrusting of Malatya Metamorphics
with chloritoid-bearing zone on the Pütürge Metamorphics in the
eastern Doûan ehir region.

thoclase (partly perthitic), muscovite, biotite and chlorite,
and has holocrystalline granular texture, reflecting its origi-
nal granitic nature. Yellowish-brown, grey-black garnet-mica
schists/gneisses from the middle to upper parts are better foli-
ated and becoming lustrous, and some contain marble and
amphibolite lenses. Schists and gneisses – the most wide-
spread lithologies in the Pütürge area – can be listed (in as-
cending order) as kyanite-mica schists, biotite-amphibolites,
garnet-kyanite-muscovite mica schists, garnet-andalusite-
mica gneisses/schists and albite-chlorite-muscovite schists,
and calc-schists. Sillimanite-mica, garnet-biotite, kyanite-bio-
tite-albite and kyanite-staurolite-sillimanite gneisses/schists
also occur in the Doûan ehir area. Amphibolite lenses from
the lower and middle parts of the unit are composed of
tschermakitic hornblende and plagioclase, and show typical
grano-nematoblastic texture.

Brownish grey-black marbles (quartz-albite marble,

chlorite marble), calc-schist alternations, and grey-brown
chloritic and albitic schist intercalations (Fig. 6) occur in
upper levels within both the Pütürge and Doûan ehir areas
and constitute a low-grade (greenschist-facies) metamor-
phic cover for the high-grade metamorphic rocks. Recrys-
tallized quartz layers alternate with fine-grained
chloritic-albitic layers in some chlorite-albite schists

Fig. 6. Vertical distributions of the lithology and mineralogical composition of Carbon-
iferous-Permian parts of the Pütürge Metamorphics (mineral abbreviations as in Fig. 2).

204

BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

(Fig. 3e). The calc-schists are typified by lepido-granoblas-
tic texture and contain oriented muscovite and biotite min-
erals within a calcitic groundmass (Fig. 3f).

X-ray mineralogy

Keban Metamorphics

The metamorphic rocks are composed, in order of abun-

dance, mainly of calcite, phyllosilicates, quartz, albite and
dolomite. Phyllosilicate minerals include illite, smectite,
chlorite, kaolinite, and scarce mixed-layered chlorite-smec-
tite (C-S), chlorite-vermiculite (C-V) and illite-smectite (I-S)
(Fig. 2). The main phyllosilicate associations are illite +
vermiculite + smectite, illite + kaolinite + smectite ± chlorite,
smectite + illite ± C-S ± I-S ± kaolinite, chlorite + illite ± kaoli-
nite ± smectite, illite + chlorite + kaolinite (Fig. 7). The pres-
ence of smectite and smectite-bearing mixed-layers in the
epimetamorphic rocks seems to be related to metacarbonates
and organic-material-rich rocks. As previously indicated by
Frey (1987), in metacarbonates and organic-matter-rich sedi-
ments, smectites may persist into the epizone, and the aggra-
dation of illite may be retarded (as compared to metaclastites)
by a deficiency of potassium.

cell dimensions range from 0.8990 to 0.9035 nm and

average 0.9014 nm for the muscovitic-phengitic white K-mi-
cas (Table 1), indicating the lower parts of the intermedi-
ate-pressure facies of Guidotti & Sassi (1976). d

060,331

—

values for white K-micas in the biotite-bearing samples re-
flect the totally phengitic composition. d

060,331

—

or b

val-

ues and basal peak ratios for the K-micas from the three
rock units are plotted in Fig. 8. The biotite-bearing sam-
ples show lower basal peak ratios than the muscovitic
ones, as previously suggested by Esquevin (1969).

Chlorites in the Keban Metamorphics are chamosite and

clinochlore; their Si contents are higher than those of chlo-
rites in the Malatya and Pütürge Metamorphics (Table 2;
Fig. 9). Consistent with the conclusions of Zane et al.
(1998), the large variations in the Fe and Mg contents of the
chlorites are related to a wide variation in bulk-rock compo-
sitions; chlorites in the calcareous phyllites have relatively
higher Fe than those in the metabasic rocks (Table 2).

KI values for the K-micas of 11 samples, lacking or con-

taining only minor carbonate, indicate epizonal condi-
tions (Fig. 10), except for two biotite-bearing samples with
higher KI values. This anomaly reflects the broad interfer-
ence effect of biotite basal peaks (Frey 1987). AI values
for the chlorites also indicate epizonal conditions. The
polytypes of the micas are 2M

and 1M for muscovites

Table 1: Crystallochemical data of white K-micas and organic reflection values.

Table 2: Mean basal reflections, peak intensity ratios and structural formulas of chlorites.

206

BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

and biotites, respectively. Chlorite and kaolinite-group
minerals are of the IIb and kaolinite polytypes, respectively.

Malatya Metamorphics

The lithologies within this major unit are composed

chiefly of phyllosilicates, quartz, albite, calcite, dolomite
and chloritoid. Phyllosilicate minerals include muscovite,
chlorite, paragonite, kaolinite/dickite, and minor C-V, C-S
and I-S (Fig. 4). The most widespread phyllosilicate
parageneses are muscovite+chlorite, muscovite + chlorite+pa-
ragonite, muscovite + chlorite + paragonite + kaolinite/ dick-
ite (Fig. 7). The appearances of mixed-layer C-V, C-S and
smectite are inconsistent with the epizonal grade, and

Fig. 8. d

060

or b

cell dimension vs. I

002

001

relationships in the K-mi-

cas. Pressure facies boundaries taken from Guidotti & Sassi (1986).
S-shaped curve is indicated boundary between K-micas with biotite
and without biotite (from Bozkaya & Yalçôn 2004a).

Fig. 9. Si-Fe/(Fe + Mg) contents of the chlorites (nomenclatures of
clinochlore and chamosite from Bailey 1980).

Fig. 10. Kübler index vs. I

002

001

diagram in the K-micas (data

related to Yumrudaû Nappe of Alanya Metamorphics from Boz-
kaya & Yalçôn 2004a).

probably reflect retrograde alteration (e.g. Nieto et al.
1994) during post-metamorphic processes.

The paragonite components (i.e. interlayer cation Na) in

muscovite, which coexists with paragonite, reach up to
20 % (mean 9 %); these values indicate temperature con-
ditions lower than 400 ºC according to the thermometric
diagrams of several authors (Chatterjee & Flux 1986;
Blencoe et al. 1994; Guidotti et al. 1994a,b). The d

(002)

basal spacings of the paragonite and muscovite peaks are
(Table 2), except for in two samples, outside the ranges
suggested by Zen & Albee (1964); this may be a result of
celadonitic substitution in muscovite (Chatterjee 1971;
Mposkoz & Perdikatzis 1981; Guidotti et al. 1994c) or
due to fine-grained paragonitic mica in the matrix (Craig
et al. 1982; Dimberline 1986; Milodowski & Zalasiewicz
1991; Li et al. 1994).

The b

values of the white K-micas (0.8981—0.9025 nm,

mean 0.9005 nm) indicate lower pressure conditions than
those of the Keban Metamorphics. The b

values and basal

peak ratios of the K-micas fall in different areas in the
Pütürge and Keban Metamorphics (Fig. 8).

The Fe

contents of chlorites are higher than in the Keban

and Pütürge Metamorphics, which show a mean chamositic
composition (Si

2.68

1.32

)

(Mg

1.64

1.32

3.04

)

(OH)

(Table 2; Fig. 9). The most Fe-rich chlorites are found in the
metasandstones, metasiltstones and metacarbonates.

KI values ( º2 = 0.12—0.29, mean 0.17) for 39 samples

correspond to epizonal conditions (Fig. 10). AI values are
within the range º2 = 0.09—0.24 (mean 0.13) suggesting
similar conditions (Árkai 1991). The muscovite and chlo-
rite are of the 2M

and IIb polytypes, respectively.

Pütürge Metamorphics

The Carboniferous-Permian low-grade metamorphic cover

rocks of the Pütürge Metamorphics are probably equivalent
to levels in the Keban and Malatya Metamorphics, and are
made up mainly of calcite, albite, quartz and phyllosilicates.

207

ORIGIN OF THE SOUTHEAST ANATOLIAN METAMORPHIC COMPLEX (TURKEY)

The clay fractions of these rocks comprise illite, chlorite, C-S
and I-S (Fig. 6). The principal phyllosilicate assemblages are
illite+chlorite, illite+C-S±chlorite and/or I-S (Fig. 7). The
amounts of C-S and I-S increase upwards, especially in the
calc-schists.

The b

values of the white K-micas range from 0.9019

to 0.9032 nm (mean 0.9026 nm), revealing a phengitic
composition indicative of higher pressure conditions than
the Keban and Malatya Metamorphics (Fig. 8).

Chlorites in the metacarbonate rocks have Mg-rich com-

positions – namely clinochlore; their chemistries plot in
a small field which differs from the chlorites of the
Malatya and especially the Keban Metamorphics (Fig. 9).
With regard to phyllosilicate polytypes, the muscovite
and chlorite are 2M

and IIb, respectively.

Organic-matter reflectances

The reflectance measured in six metapelite samples from

the Keban and Malatya Metamorphics varies from 5.33 to
7.32 Rm

oil

% (mean 6.22 Rm

oil

%) and 4.52 to 6.58 Rm

oil

(mean 5.84 Rm

oil

%), respectively. The rank of coalification

corresponds to the meta-anthracite to semi-graphite stages
(Teichmüller 1987). High standard-deviation numbers for
randomly measured OMR (organic matter reflection) val-
ues (Table 1) indicate high anisotropy (or bireflectance) for
the organic matter.

Discussion and conclusions

The metamorphic units in the southeast Anatolian oro-

genic belt are characterized by distinct differences in re-
gard to their textures and especially their mineralogical
compositions; however, these units show rather similar
stratigraphic and lithological characteristics.

The index metamorphic minerals of the metabasic levels

of the Keban Metamorphics are represented by epidote,
tremolite/actinolite, albite and biotite. The phyllosilicate
minerals are characterized by kaolinite, smectite, vermiculite,
I-S and Al-poor chlorites. An epidote + albite + tremolite/
actinolite + IIb chlorite ± 1M biotite assemblage, epizonal KI
values, and moderate b

values in 2M

white K-micas re-

flect the intermediate-pressure facies and organic-matter re-
flectance values show meta-anthracitic maturation, thus
indicating metamorphism below  ~ 300—400 ºC temperature
with pressures of  ~ 0.5—0.6 GPa. Phengitic micas with mod-
erate  b

values, and mica and chloritic associations indicate

low heat flow ( < 25 ºC/km) and moderate- to high-pressure
conditions in a convergent basin (e.g. Merriman & Frey
1999; Merriman 2005). The tectonic microfabrics are typi-
cally parallel or subparallel to bedding planes, and rarely
inclined and crenulated as a result of bedding-plane slip
and imbrication, as noted by Merriman (2002) for fabric de-
velopment in convergent basins.

The Malatya Metamorphics are represented by chloritoid,

paragonite, dickite and Mg-rich chlorites. The index-mineral
assemblages (chloritoid, paragonite, dickite), epizonal crys-

tallinity, meta-anthracitic coalification degrees and lower b

values for the 2M

white K-micas indicate a low-pressure fa-

cies, with ~ 300—350 ºC and ~ 0.3—0.4 GPa temperature and
pressure conditions, respectively. Phengite-poor micas with
low b

cell dimensions and the presence of dickite and 2M

paragonite show a metamorphic event that originated under
relatively high heat-flow conditions ( > 35 ºC/km) in an ex-
tensional setting (e.g. Merriman & Frey 1999; Merriman
2005). The abundance of well-developed slaty and crenula-
tion cleavages in the anchi-epimetamorphic rocks is assumed
to reflect temperatures reached within an extensional-basin
setting, which was maintained during basin inversion and de-
formation, thus enhancing ductile strain, recrystallization
and cleavage development (e.g. Warr et al. 1991; Bozkaya
& Yalçôn 2004b). This evolution marks a counterclockwise
P-T-t evolution in an extensional basin (Fig. 11).

Low- and high-grade metamorphic parts of the Pütürge

Metamorphics are composed of index minerals such as
epidote, albite, biotite and amphibole, garnet, staurolite,
kyanite, sillimanite and andalusite minerals, respectively.
The Carboniferous-Permian low-grade metamorphic parts
comprise phyllosilicates such as epizonal 2M

white K-mica,

Mg-rich IIb chlorite, and C-S and reflect the metamor-
phism under ~ 300—400 ºC temperature and pressures of
~ 0.5—0.6 GPa in a convergent basin.

The appearance of smectite and mixed-layer clay miner-

als (C-V, C-S and I-S) in high anchizonal to epizonal meta-
morphic rocks from the Keban, Malatya and Pütürge
Metamorphics is inconsistent with the metamorphic index-
mineral phases; thus, these may reflect lithological effects
(Frey 1987) and post-metamorphic alteration processes
(Nieto et al. 1994).

Fig. 11. Hypothetical metamorphic evolution of the SAMC show-
ing the different metamorphism characteristics on the basis of
their tectonic settings (b

lines from D’Amico et al. 1987; tectonic

settings from Merriman & Frey 1999).

208

BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

Data obtained from coeval parts of the Malatya and Ke-

ban Metamorphics demonstrate that these are of different
origin; this contradicts the hypothesis that they shared a
common origin (Yôlmaz 1993). Thus, the compound clas-
sification – the “Keban-Malatya Unit” – of Yôlmaz et al.
(1993) is probably incorrect.

The Keban and Malatya Metamorphics are known to be

of Tauride origin, as previously suggested by many authors
(e.g. Yazgan 1984; Göncüoûlu & Turhan 1984; Yazgan &
Chessex 1991; Yôlmaz 1993; Yôlmaz et al. 1993); but those
workers did not explain the origin of the Tauride units.
However, Yôlmaz et al. (1993) suggested that the Keban
Metamorphics originated from the autochthonous Geyikdaûô
Unit, as concluded in the present study. Coaly metacarbon-
ate levels and phyllosilicate compositions suggest that the
Keban Metamorphics were derived from the Eastern
Tauride Autochthon or Geyikdaûô Unit (Bozkaya & Yalçôn
2004b), whereas the Malatya Metamorphics show
important lithological (chloritic oolitic/pisolitic levels) and
mineralogical (Na-mica, dickite and white K-micas with low
b

values) similarities to the allochthonous Aladaû Unit.

The contrasting P-T evolutions of the SAMC are related

to their being metamorphosed in different geotectonic set-
tings. The Keban and Pütürge Metamorphics developed in
an Alpine collision zone, whereas the Malatya Metamor-
phics developed in an extensional marginal basin, and
clearly do not provide evidence of a collisional setting
(Fig. 11). Therefore, the Malatya Metamorphics must be
allochthonous; that is, transported from another source.
Structural orientations indicate southward emplacement.
In particular, mineralogical and lithological similarities
with northern allochthonous Tauride units (Bolkardaûô
and Aladaû Units; Bozkaya & Yalçôn 2004b) imply an ori-
gin from the north for the Malatya Metamorphics
(Fig. 12). In the light of the thrusted boundaries with the
Middle Eocene Maden Unit, and the unconformably over-
lying Early Miocene sedimentary rocks, the allochtho-
nous transport of the Malatya Metamorphics must have
occurred in the post-Eocene—Early Miocene time interval.
This tectonic event corresponded to a second major epi-

Fig. 12. Schematic section displaying the tectonic structure of the Southeast Anatolian Metamorphic area.

sode of Alpine deformation in the southeast Anatolian
orogenic belt.

Acknowledgments: This paper is a product of a project
funded (M-163) by the Research Foundation of Cumhu-
riyet University. The authors would like to express their
thanks to Fatma Yalçôn for her assistance with laboratory
studies, ùbrahim Altunta from Co ta Mining Company
for logistical help and Dr. A. ùhsan Karayiûit (Hacettepe
University, Ankara) for measurement of organic-matter re-
flectances. We acknowledge, with thanks, Prof. Dr.
Francesco P. Sassi and an anonymous reviewer for criti-
cally reviewing the manuscript and for suggesting very
valuable improvements, and Dr. Steven K. Mittwede for
his English-language assistance.

References

Árkai P. 1991: Chlorite crystallinity: an empirical approach and

correlation with the illite crystallinity, coal rank and mineral
facies as exemplified by Palaeozoic and Mesozoic rocks of
northeast Hungary. J. Metamorph. Geology 9, 723—734.

Árkai P., Sassi F.P. & Sassi R. 1995: Simultaneous measurements of

chlorite and illite crystallinity: a more reliable tool for moni-
toring low to very low grade metamorphism in metapelites. A
case study from the Southern Alps (NE Italy). Eur. J. Mineral.
7, 1115—1128.

Asutay J. 1987: Geology of the Baskil (Elazôû) area and petrology

of the Baskil Magmatics. Miner. Res. Explor. Inst. Turkey Bull.
107, 49—72 (in Turkish).

Asutay H.J., Turan M., Poyraz N., Orhan H., Tarô E. & Yazgan E.

1986: Geology of the Eastern Taurides in the vicinity of Ke-
ban-Baskil (Elazôû). Miner. Res. Explor. Inst. Turkey Report
8007, 1—154 (in Turkish).

Bailey S.W. 1980: Summary of recommendations of AIPEA no-

menclature committee on clay minerals. Amer. Mineralogist
65, 1—7.

Bailey S.W. 1988: X-ray diffraction identification of the polytypes of

mica, serpentine, and chlorite. Clays Clay Miner. 36, 193—213.

Beyarslan M. & Bingöl A.F. 2000: Petrology of a supra-subduction

zone ophiolite (Elazôû, Turkey). Canad. J. Earth Sci. 37,
1411—1424.

209

ORIGIN OF THE SOUTHEAST ANATOLIAN METAMORPHIC COMPLEX (TURKEY)

Blencoe J.G., Guidotti C.V. & Sassi F.P. 1994: The paragonite-mus-

covite solvus: II. Numerical geothermometers for natural, qua-
sibinary paragonite-muscovite pairs. Geochim. Cosmochim.
Acta 58, 2277—2288.

Bozkaya Ö. & Yalçôn H. 2000: Very low-grade metamorphism of

Upper Paleozoic-Lower Mesozoic sedimentary rocks related to
sedimentary burial and thrusting in Central Taurus Belt, Kon-
ya, Turkey. Int. Geol. Rev. 42, 353—367.

Bozkaya Ö. & Yalçôn H. 2004a: New mineralogical data and impli-

cations for the tectono-metamorphic evolution of the Alanya
Nappes, Central Tauride Belt, Turkey. Int. Geol. Rev. 46,
347—365.

Bozkaya Ö. & Yalçôn H. 2004b: Diagenetic to low-grade metamor-

phic evolution of clay mineral assemblages in Palaeozoic to
early Mesozoic rocks of the Eastern Taurides, Turkey. Clay
Miner. 39, 481—500.

Bozkaya Ö. & Yalçôn H. 2005: Diagenesis and very low-grade

metamorphism of the Antalya Unit: Mineralogical evidence on
the Triassic rifting, Alanya-Gazipa a, Central Taurus Belt, Tur-
key. J. Asian Earth Sci. 25, 109—119.

Bozkaya Ö., Yalçôn H. & Göncüoûlu M.C. 2002: Mineralogic and

organic responses to the stratigraphic irregularities: an example
from the Lower Paleozoic very low-grade metamorphic units
of the Eastern Taurus Autochthon, Turkey. Schweiz. Mineral.
Petrogr. Mitt. 82, 355—373.

Brindley G.W. 1961: Chlorite minerals. In: Brown G. (Ed.): The X-

ray identification and crystal structures of clay minerals. Min-
eral. Soc., London, 242—296.

Brindley G.W. 1980: Quantitative X-ray mineral analysis of clays.

In: Brindley G.W. & Brown G. (Eds.): Crystal structures of
clay minerals and their X-ray identification. Mineral. Soc.,
London, 411—438.

Brown G. & Brindley G.W. 1980: X-ray diffraction procedures for

clay mineral identification. In: Brindley G.W. & Brown G.
(Eds.): Crystal structures of clay minerals and their X-ray iden-
tification. Mineral. Soc., London, 305—360.

Chagnon A. & Desjardins M. 1991: Détermination de la composi-

tion de la chlorite par diffraction et microanalyse aux rayons
X. Canad. Mineralogist 29, 245—254.

Chatterjee N.D. 1971: Phase equilibria in the Alpine metamorphic

rocks of the environs of the Dora-Maira-Massif, Western Ital-
ian Alps. Neu. Jb. Mineral. Abh. 114, 181—245.

Chatterjee N.D. & Flux S. 1986: Thermodynamic mixing properties

of muscovite-paragonite crystalline solutions at high tempera-
tures and pressures, and their geological applications. J. Pe-
trology 27, 677—693.

Craig J., Fitches W.R. & Maltman A.J. 1982: Chlorite-mica stacks

in low-strain rocks from Central Wales. Geol. Mag. 119,
243—256.

D’Amico C., Innocenti C. & Sassi F.P. 1987: Magmatismo e Meta-

morfismo. UTET, Torino, 1—536.

Dimberline A.J. 1986: Electron microscope and microprobe analy-

sis of chlorite-mica stacks in the Wenlock turbidites, mid
Wales, UK. Geol. Mag. 123, 299—306.

Esquevin J. 1969: Influence de la composition chimique des illites

sur leur cristallinité. Bull. Cent. Rech. Pau SNPA 3, 147—153.

Frey M. 1987: Very low-grade metamorphism of clastic sedimenta-

ry rocks. In: Frey M. (Ed.): Low temperature metamorphism.
Blackie & Son, Glasgow, 9—58.

Göncüoûlu M.C. 1997: Distribution of Lower Paleozoic units in the

Alpine Terranes of Turkey: paleogeographic constraints. In:
Göncüoûlu M.C. & Derman A.S. (Eds.): Lower Palaeozoic
evolution in Northwest Gondwana. Turkish Assoc. Petrol.
Geol. Spec. Publ. 3, 13—24.

Göncüoûlu M.C. & Turhan N. 1984: Geology of the Bitlis Meta-

morphic Belt. In: Tekeli O. & Göncüoûlu M.C. (Eds.): Geolo-

gy of the Taurus Belt. Proceedings of International Sympo-
sium Proceedings on the Geology of the Taurus Belt. Miner.
Res. Explor. Inst. Turkey, Spec. Publ. 237—244.

Göncüoûlu M.C., Dirik K. & Kozlu H. 1997: General charactersitics

of pre-Alpine and Alpine Terranes in Turkey: explanatory
notes to the terrane map of Turkey. Ann. Géol. Pays Hellén.
37, 515—536.

Guggenheim S., Bain D.C., Bergaya F., Brigatti M.F., Drits A.,

Eberl D.D., Formoso M.L.L., Galan E., Merriman R.J., Peacor
D.R., Stanjek H. & Watanabe T. 2002: Report of the AIPEA
nomenclature committee for 2001: order, disorder and crystal-
linity in phyllosilicates and the use of the “Crystallinity Index”.
Clay Miner. 37, 389—393.

Guidotti C.V. & Sassi F.P. 1976: Muscovite as a petrogenetic indica-

tor mineral in pelitic schists. Neu. Jb. Miner. Abh. 127, 97—142.

Guidotti C.V. & Sassi F.P. 1986: Classification and correlation of

metamorphic facies series by means of muscovite b

data from

low-grade metapelites. Neu. Jb. Miner. Abh. 153, 363—380.

Guidotti C.V., Sassi F.P., Blencoe J.G. & Selverstone J. 1994a: The

paragonite-muscovite solvus: I. P-T-X limits derived from Na-
K compositions of natural, quasibinary paragonite-muscovite
pairs. Geochim. Cosmochim. Acta 58, 2269—2275.

Guidotti C.V., Sassi F.P., Sassi R. & Blencoe G. 1994b: The effects

of ferromagnesian components on the paragonite-muscovite
solvus: a semiquantitative analysis based on chemical data for
natural paragonite-muscovite pairs. J. Metamorphic Geology
12, 779—788.

Guidotti C.V., Yates M.G., Dyar M.D. & Taylor M.E. 1994c: Petro-

genetic implications of the Fe

content of muscovite in pelitic

schists. Amer. Mineralogist 79, 793—795.

Guidotti C., Sassi F.P., Comodi P., Zanazzi P.F. & Blencoe J.G.

2005: Does the crystal chemistry of layer silicates play a role
in slaty cleavage formation? Truth and beauty in metamor-
phism, atribute to Dugald Carmichael. Canad. Mineralogist
43, 311—326.

Karaman T., Poyraz N., Bakôrhan B., Alan ù., Kadônkôz G., Yôlmaz

H. & Kôlônç F. 1993: Geology of the Malatya-Doûan ehir-Çe-
likhan area. Miner. Res. Explor. Inst. Turkey Report 9587, 1—54
(in Turkish).

Kisch H.J. 1991: Development of slaty cleavage and degree of vey-

low-grade metamorphism: a review. J. Metamorphic Geology
9, 735—750.

Kisch H.J., Sassi R. & Sassi F.P. 2006: The b

lattice parameter and

chemistry of phengites from HP/LT metapelites. Eur. J. Miner-
al. 18, 207—222.

Kübler B. 1968: Evaluation quantitative du métamorphisme par la

cristallinité de l’illite. Bull. Cent. Rech. Pau SNPA 2, 385—397.

Li G., Peacor D.R., Merriman R.J. & Roberts B. 1994: The diagenetic

to low-grade metamorphic evolution of matrix white micas in
the system muscovite-paragonite in a mudrock from Central
Wales, United Kingdom. Clays Clay Miner. 42, 369—381.

Merriman R.J. 2002: Contrasting clay mineral assemblages in Brit-

ish Lower Palaeozoic slate belts: the influence of geotectonic
setting. Clay Miner. 37, 207—219.

Merriman R.J. 2005: Clay minerals and sedimentary basin history.

Eur. J. Mineral. 17, 7—20.

Merriman R.J. & Frey M. 1999: Patterns of very low-grade meta-

morphism in metapelitic rocks. In: Frey M. & Robinson D.
(Eds.): Low-grade metamorphism. Blackwell Science, 61—107.

Milodowski A.E. & Zalasiewicz J.A. 1991: The origin, sedimenta-

ry, diagenetic and metamorphic evolution of chlorite-mica
stacks in Llandovery sediments of central Wales, UK. Geol.
Mag. 128, 263—278.

Mposkoz E. & Perdikatzis V. 1981: Die Paragonit-Chloritoid

führenden Schiefer des südwestlichen Bereiches des Kerkis auf
Samos (Greichenland). Neu. Jb. Miner. Abh. 142, 292—308.

210

BOZKAYA, YALÇIN, BA IBÜYÜK, ÖZFIRAT and YILMAZ

MTA 2002: 1 : 500,000 scaled geological map series of Turkey. Si-

vas section. Miner. Res. Explor., Ankara.

Neubauer F. & Sassi F.P. 1993: The Austro-Alpine quartzphyllites

and related Paleozoic formations. In: von Raumer J.F. & Neu-
bauer F. (Eds.): The pre-Mesozoic geology in the Alps.
Springer-Verlag, 423—439.

Nieto F. 1997: Chemical composition of metapelitic chlorite: X-ray

diffraction and optical property approach. Eur. J. Mineral. 9,
829—841.

Nieto F., Velilla N., Peacor D.R. & Ortega-Huertas M. 1994: Re-

gional retrograde alteration of sub-greenschist facies chlorite
to smectite. Contr. Mineral. Petrology 115, 243—252.

Özgül N. 1976: Some geological aspects of the Taurus orogenic

belt (Turkey). Geol. Soc. Turkey Bull. 19, 65—78 (in Turkish).

Özgül N. & Tur ucu A. 1984: Stratigraphy of the Mesozoic car-

bonate sequence of the Munzur Mountains (Eastern Taurides).
In: Tekeli O. & Göncüoûlu M.C. (Eds.): Geology of the Tau-
rus Belt. Proceedings of International Symposium Proceedings
on the Geology of the Taurus Belt. Miner. Res. Explor. Inst.
Turkey, Spec. Publ. 173—180.

Perinçek D. & Kozlu H. 1984: Stratigraphy and structural relations

of the units in the Af in-Elbistan-Doûan ehir region (Eastern
Taurus). In: Tekeli O. & Göncüoûlu M.C. (Eds.): Geology of
the Taurus Belt. Proceedings of International Symposium Pro-
ceedings on the Geology of the Taurus Belt. Miner. Res. Ex-
plor. Inst. Turkey, Spec. Publ. 181—198.

Rieder M., Guidotti C.V., Sassi F.P. & Weiss Z. 1992: Muscovites:

060

versus d

060,331

—

spacings: its use for geobarometric purpos-

es. Eur. J. Mineral. 4, 843—845.

Sassi F.P. & Scolari A. 1974: The b

value of the potassic white mi-

cas as a barometric indicator in low-grade metamorphism of
pelitic schists. Contr. Mineral. Petrology 45, 143—152.

Sassi F.P., Cesare B., Mazzoli C., Peruzzo L., Sassi R. & Spiess R.

2004: The crystalline basements of the Italian eastern Alps: a
review of the metamorphic features. Periodico di Mineralogia
73, 23—42.

engör A.M.C. & Yôlmaz Y. 1981: Tethyan evolution of Turkey: a

plate tectonic approach. Tectonophysics 75, 181—241.

Teichmüller M. 1987: Organic material and very low-grade meta-

morphism. In: Frey M. (Ed.): Low temperature metamor-
phism. Blackie & Son, Glasgow, 114—161.

Warr L.N. & Rice A.H.N. 1994: Interlaboratory standartization and

calibration of clay mineral crystallinity and crystallite size data.
J. Metamorphic Geology 12, 141—152.

Warr L.N., Primmer T.J. & Robinson D. 1991: Variscan very low-

grade metamorphism in southwest England: a diastathermal and
thrust-related origin. J. Metamorphic Geology 9, 751—764.

Winkler G.H.F. 1976: Petrogenesis of metamorphic rocks. Spring-

er-Verlag, NewYork, 1—334.

Yalçôn H., Bozkaya Ö. & Ba ôbüyük Z. 1999: Phyllosilicate miner-

alogy of very low-grade Malatya metamorphites of Upper Pa-
leozoic age. Proc. 52

Geol. Cong. of Turkey, 10—12 May,

Ankara, 271—278 (in Turkish with English abstract).

Yardley B.W.D. 1989: An introduction to metamorphic petrology.

Longman Scientific & Technical, New York, 1—248.

Yazgan E. 1984: Geodynamic evolution of the Eastern Taurus re-

gion. In: Tekeli O. & Göncüoûlu M.C. (Eds.): Geology of the
Taurus Belt. Proceedings of International Symposium Pro-
ceedings on the Geology of the Taurus Belt. Miner. Res. Ex-
plor. Inst. Turkey, Spec. Publ. 199—208.

Yazgan E. 1987: Geology of the northeastern Malatya and geody-

namical evolution of Eastern Taurides. Miner. Res. Explor.
Inst. Turkey Report 2268, 1—178.

Yazgan E. & Chessex R. 1991: Geology and evolution of the

Southeastern Taurides in the region of Malatya. Turkish Assoc.
Petrol. Geol. Bull. 3, 1—42.

Yôlmaz A., Bedi Y., Uysal ., Yusufoûlu H. & Aydôn N. 1993:

Geological structure of the area between Uzunyayla and Berit-
daû of the Eastern Taurids. Turkish Assoc. Petrol. Geol. Bull.
5, 69—87.

Yôlmaz Y. 1993: New evidence and model on the evolution of the

southeast Anatolian orogen. Geol. Soc. Amer. Bull. 105,
251—271.

Zane A., Sassi R. & Guidotti C.V. 1998: New data on metamorphic

chlorite as a petrogenetic indicator mineral, with special regard
to greenschist-facies rocks. Canad. Mineralogist 36, 713—726.

Zen E-AN. & Albee A.L. 1964: Coexistant muscovite and parago-

nite in pelitic schists. Amer. Mineralogist 49, 904—925.