Palaeovegetation and paleoclimate in the SW Turkey – a study based on the early-middle Miocene coal-bearing sediments from the Büyük Menderes Graben

Abstract

This study provides the age of coal-bearing sediments of the Büyük Menderes Graben (BMG) and palaeoclimatic and palaeovegetational change from the early to late Miocene. Two palynofloras, the Başçayır and Kızılcayer, are distinguished in the late Burdigalian-early Langhian, and Serravallian-Tortonian boundary. According to the microfloral composition of the Başçayır palynoflora is characterized by subtropical elements, and palaeoclimate is warm subtropical, with the coldest month mean temperature (CMT) 8–13 oC. Based on the palynoflora, the coal-bearing sediments were deposited in the fluvial-lacustrine environments. The abundances of gymnosperm species and the mean annual range of temperature (MART) point out high and middle altitude areas during the deposition of coal-bearing sediments. Based on the Kızılcayer palynofloral composition, palaeoclimate is the warm temperate (CMT: 3.1–13.3 oC), also the abundant presence of herbaceous species indicate open land areas in the Aydın-Kızılcayer area despite the existences of swampy-lowland environments.According to described palynofloral composition, the palaeotopographic conditions of the southern part of the BMG (Aydın-Kuloğulları) are generally higher than the northern parts (Aydın-Başçayır), and deposition areas in this graben are significantly uplifted from the late Burdigalian to early Tortonian. The regional palaeoclimatic condition from the early to late Miocene changed from warm subtropical to temperate in western Anatolia. The palaeotopographic changes related to the tectonic events and/or uplift of the Menderes Massive in western Anatolia could have been effective on regional paleoclimate during the deposition in the BMG, and this uplifting existed in the late Burdigalian and continued until the late Miocene.