GEOLOGICAL SETTING AND PETROGRAPHICAL CHARACTERISTICS OF JURASSIC AKDAĞ REEFAL LIMESTONES (GÜNDOĞMUŞ-MANAVGAT) ON THE NE-OF ANTALYA, TURKEY

Geologically, the Akdag limestone massif is located on the eastern side of Isparta Angle. Tectonically, Isparta Angle was formed due to bending of Taurus carbonate axis in the north of Antalya Gulf during the Late... [ view full abstract ]

Geologically, the Akdag limestone massif is located on the eastern side of Isparta Angle. Tectonically, Isparta Angle was formed due to bending of Taurus carbonate axis in the north of Antalya Gulf during the Late Miocene-Early Pliocene period.
Isparta Angle is one of the most prominent neotectonic structure within the SW-Anatolia located on the north of Antalya Gulf. The NE-trending Fethiye-Burdur fault zone and NW-trending Akşehir fault limit Isparta Angle from the west and the east, respectively. Isparta Angle province contains two Mesozoic carbonate platform, which are Beydağları that are on west of the Gulf of Antalya, and Akseki-Anamas to the east. The platforms are seperated and tectonically overlained by the allocthonous nappe systems.
The Akseki-Anamas autochthonous carbonate sequence is mainly composed of massive and thick bedded limestones and dolomites between Triassic and Cretaceous in age. Due to E-W directionaly compression, the NW-trending overthrust fault systems are formed within the eastern side of Isparta Angle and also in the Akdağ marble area.
On the south of the study area, the Jurassic Akdağ limestone massif is overthursted on the Eocene turbiditic sedimentary sequence. Due to overthrusting, the lowermost part of the Akdağ limestone massif is locally brecciated. The thickness of the brecciated zone varies in between 50 and 200 cm. On the other hand, locally the conjugate fracture systems developed within the Akdağ limestone massif due to this overthrusting.
The Jurassic Akdağ carbonate sequence in the study area is mainly composed of light beige and thick bedded or massive limestones. The main portion of Akdağ carbonate sequence is formed by the reefal limestones. The reefal limestones of the Akdağ masif are generally massive and very thick bedded and are rare fractured. In the licenced areas the reefal portions of the Akdağ limestone sequence can be seperated easily.
Petrographically, the Akdağ reefal limestones (marbles) contain sparitic calcite and various bioclastic (belonging to bivalvies and foraminifers) allochemical constituents. The microfissures and the porosities in this recrystallized matrix are generally totally filled and well cemented by the secondary calcite. Due to recrystallization the much of fosil remains can not identify. These petrographic features and field observations of Akdağ limestone samples indicate the shallow marine (neritic) and barrier reef environments. The reefal character may be wins massive and homogene features of the Akdağ limestones.