The Middle Miocene Palynofloras of the Salihpaşalar Lignite Mine
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Palaeobiodiversity and Palaeoenvironments https://doi.org/10.1007/s12549-018-0345-0 ORIGINAL PAPER The middle Miocene palynofloras of the Salihpaşalar lignite mine (Yatağan Basin, southwest Anatolia): environmental characterisation and comparison with palynofloras from adjacent basins Johannes M. Bouchal1,2 Received: 23 December 2017 /Revised: 23 March 2018 /Accepted: 29 May 2018 # The Author(s) 2018 Abstract As the third part of an ongoing investigation of middle Miocene palynofloras in the Yatağan Basin (YB), southwestern Anatolia, the palynofloras of the Salihpaşalar lignite mine in the main YB were studied. Seven types of algal spores, aplanospores/zygospores or cysts, six types of lycophyte and fern spores, 12 types of gymnosperm pollen and 90 types of angiosperm pollen were identified. Of a total of ca. 140 plant taxa described from the YB, over 10% are confined to the Salihpaşalar assemblage. Differences between coeval palynofloras of the Sekköy Member might reflect changing or prograding depositional environments. A number of rare accessorial taxa reflect these local differences: Pilularia, Valeriana, Drosera and Persicaria aff. amphibia only occur at Salihpaşalar and are typical of shallow water or temporary ponds associated with a lake shore. Apart from this, all the palynofloras, originating from the lignite seams and overlying limnic limestones (uppermost Turgut and Sekköy Member), of the YB are strongly indicative of extensive woody vegetation with a dominance of diverse Fagaceae and Pinaceae. In addition, a list comparing the well-documented YB palynomorphs to morphologically similar palynomorphs of published late early to middle Miocene plant assemblages of western Anatolian was compiled. Such a comparison reveals that in many instances different taxon names have been used to denote the same taxa. Hence, resolving these synonymies is a prerequisite of any meaningful comparison of palynofloras in the region. Keywords Neogene . Western Anatolia . Dispersed pollen . Scanning electron microscopy . Botanical nomenclature . Artificial nomenclature Introduction 1999;Popovetal.2004; van Hinsbergen and Schmid, 2012). In southwestern Anatolia, the Denizli, Söke and Yatağan Basin (YB) High tectonic activity in western Anatolia during the late Cenozoic among others formed with the onset of the Miocene subsidence associated with the collision of the Arabian and Anatolian plates (Alçiçek 2010). Age correlation of these Miocene fault-bounded resulted in orogeny, volcanic activity and basin formation (Rögl basins is complicated and previously suggested ages for individual basins based on different proxies have been highly controversial. Specifically, it has been demonstrated that palynological data This article is a contribution to the special issue "Taking the Orient alone are not sufficient to reliably infer the age of a particular basin Express? The role of Anatolia in mediterranean Neogene (Bouchal et al. 2016). Examples from western Anatolia for con- palaeobiogeography". flicting ages inferred from palynological data and radiometric Electronic supplementary material The online version of this article dating include the Soma Basin, for which Akgün et al. (2007) (https://doi.org/10.1007/s12549-018-0345-0) contains supplementary suggested a middle Miocene age whereas radiometric dates from material, which is available to authorized users. Ersoy et al. (2014) suggest an early Burdigalian age, the Gördes Basin, for which Akgün et al. (2007) suggested an early to middle * Johannes M. Bouchal [email protected] Serravallian age, while Purvis et al. (2005) based on radiometric dates inferred a late Aquitanian to early Burdigalian age based on 1 Department of Palaeobiology, Swedish Museum of Natural History, radiometric dates, and the Bigadiç Basin, for which Akyol and 10405 Stockholm, Sweden Akgün (1990) inferred a middle to earliest late Miocene age, while 2 Department of Palaeontology, University of Vienna, Erkületal.(2005) suggested an early Burdigalian age, based, 1090 Vienna, Austria again, on radiometric dating. Complementary data, such as Palaeobio Palaeoenv vertebrate fossils or radiometrically dated layers, are hence of basin is divided by an axial bedrock horst (metamorphic cover utmost importance for reliably inferring the age of a fossil locality. rocks of the Menderes Massif) in the smaller (ca 12 km long, Another issue that hampers the comparison of Neogene 1 km wide, south east trending) Tınaz subbasin (Fig. 1b) and sedimentary basins in western Anatolia relates to the two con- the main YB. The northern area of the main basin between cepts applied for the naming of dispersed fossil pollen and Eskihisar and Turgut (west and north of Aladağ Mountain) is spores. A substantial number of studies have been using the segregated from the southern part by a bedrock sill (Fig. 1b; artificial fossil nomenclature (strictly morphology based) for Atalay 1980; Becker-Platen 1970). The Neogene basin fill is palynomorphs, while in more recent publications, convention- up to 600 m thick and grouped into the Eskihisar Formation al botanical names are used more often. Therefore, it maybe (early to middle Miocene), the Yatağan Formation (late difficult to compare studies for a particular area, potentially Miocene to early Pliocene), and the Milet Formation (middle leading to highly redundant taxon lists. to late Pliocene). The Eskihisar Formation is subdivided in The present contribution is the third in a series of papers Turgut Member (reddened alluvial-fan deposits followed by dealing with the palynology of middle Miocene (MN6–MN7/ fluviatile deposits and lignites) and Sekköy Member (limnic 8) deposits of the upper Turgut and Sekköy Member of the marls and limestones; Fig. 1c). For the present study, the type Eskihisar Formation in southwestern Anatolia (Bouchal et al. profiles of the Turgut and Sekköy members as designated by 2016, 2017). Previous palynological studies have concentrat- Becker-Platen (1970, p. 22 ff. and pp. 26–27) were used as ed on the Eskihisar and the Tınaz lignite mines and vertebrate reference points and the boundary placed between the two localities (e.g. Benda 1971;Gemicietal.1990; Erdei et al. members where the change from siliciclastic (non- 2002; Akgün et al. 2007; Yavuz-Işıketal.2011;Koç,2017; carbonatic) to carbonate sedimentary rocks occurs. Five lig- Bouchal et al. 2016, 2017). nite fields (Eskihisar field, Tınaz field, Bağyaka field, Bayir The present investigation focuses on the Salihpaşalar lig- field, Turgut field) have been prospected in the YB. All eco- nite mine located to the south of the main YB that was nomically exploited lignite seams of the YB are confined to exploited for a short period between 2012 and 2015. The the transition zone of the Turgut and Sekköy members of the sections studied in previous papers and in the present paper Eskihisar Formation (Becker-Platen 1970;Inaneretal.2008). are strongly correlated by the palynological content of the lignite seams overlying limestones and their age is well- Age of the Salihpaşalar lignite mine section constrained by vertebrate fossils recently identified from the main coal seam of the Eskihisar lignite mine (electronic The stratigraphic chart of the mediterranean and parathetyan supplementary material in Bouchal et al., 2017) and the fossil realm has been going through several changes since the 1970s; vertebrate locality Yeni Eskihisar (Sickenberg 1975; Saraç for stratigraphic ages and ranges of Becker-Platen (1970), the 2003; Wessels 2009; The NOW Community 2018). updated corresponding age is provided based on the compiled In this paper, I will (i) describe palynological assem- stratigraphic chart of Neubauer et al. (2015). In the overview blages from a stratigraphic column at Salihpaşalar using a map of the YB, Becker-Platen (1970, pl. 3) assigned an area (ca combined scanning electron and light microscopy approach, 2 km long, 0.5 km wide) east of the village of Salihpaşalar to the (ii) compare the palynological records of three lignite mines Sekköy Member (=Sekköy Formation in Becker-Platen). in the YB, and (iii) discuss the palaeoenvironmental signal Additionally, the following age constraining fossils are listed of the palynological data from the YB palynofloras. In ad- (sample localities P419, P431, P434 in Becker-Platen 1970): dition, a list comparing the well-documented YB palyno- pulmonate gastropods—Clausilla sp.; Ostracoda— morphs to morphologically similar pollen of other late early Cytheromorpha zinndorfi, Loxoconcha granosa, Hemicythere to middle Miocene palynoassemblages of western Anatolian folliculosa, Cyprideis cf. littoralis → Helvet to Pannon (=middle strata was compiled [Supplementary Material (S) 2]. This is to late Miocene age); pharyngeal teeth of cyprinids— an attempt to accommodate previous concepts of palynolog- “Cypridopsis” biplanata → Torton (=early late Miocene). ical nomenclature (strictly morphology based) and modern Atalay (1980) reported two vertebrate fossil localities NEE of concepts of applying botanical names to palynomorphs for the village Salihpaşalar (Salihpaşalar-Kemikalan, Salihpaşalar- this region. Karaağaç; both assigned to MN12, late Tortonian to early Messinian; The NOW Community 2018) and assigned the rocks of this area to the late Miocene Yatağan Formation. So far, the Materials and methods stratigraphic relevant animal taxa of the Salihpaşalar lignite mine have not been investigated (Serdar Mayda, personal communi- Geological setting cation 2017). The here documented palynoflora