PETROGRAPHY AND ORIGIN OF DOLOMITES OF YANIKTEPE FORMATION (UPPER CRETACEOUS) IN GÜRÜN AUTOCHTHONOUS, EASTERN TAURUS TURKEY

Yıl 1995, Cilt: 117 Sayı: 117, 59 - 67, 01.10.1995

Eşref Atabey

Öz

The purpose of this study was to
reveal the petrography and origin of the Upper Cretaceous dolomites in the
Gürün autochthonous in eastern Taurus The Upper Cretaceous (Upper
Santonian-Campanian) dolomites in the Gürün autochthonous belong to the
Yanıktepe formation and are restricted to outcrops near Salyurt Yaylası,
southern slope of Kavunağılı Tepe and Toycu Tepe The Yanıktepe formation is represented
by the interfingering limestone and dolomite fades, which can be identified in
the field The limestones are massive and exhibit texture of wackestone that
contains foraminifera-macro shells (rudist). The dolomites formed as a result
of dolomitization of foraminifera-macro shell-bearing wackestones. Three types
of texture can be petrographically identified in these dolomites Type: Clear
dolomite crystals, Type 2: Filthy (blurry) dolomite crystals, Type 3: Zoned
dolomite crystals Of these, Type 1 is euhedral and subhedral, and very fine-to
fine-grained; Type 2 anhedral and subhedral, and fine-to medium-grained; Type 3
subhedral and euhedral, and fine-to medium-grained These data support that the
Upper Cretaceous dolomites in the study area could have been formed at two
different stages, early and late diagenetic The early diagenetic dolomites
(Type 1 and Type 2) are likely to form as a result of structural changes that
occurred concurrently with sedimentation in the basin during the Upper
Cretaceous The sea water fresh water mixing zones over uplifted submarine
masses (rudist-bearing limestones) are probably the most favoured environments
for dolomitization The late diagenetic ones (Type 3 texture) are wholly
tectonically controlled and correspond to the dolomites which are controlled by
fractures associated with nappe tectonics in the region

Anahtar Kelimeler

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Kaynakça

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