http://journals.cambridge.org Downloaded: 18 Nov 2014 IP address: 193.140.122.10 1. Introduction The Neogene history of south-central Turkey is marked by the development and subsequent deforma- tion of several large sedimentary basins (Adana, Mut, Misis-Andırın, Maras ¸, etc.) with predominantly marine fill-sequences. Of these, the Adana Basin is one of the most thoroughly studied, due both to its hydro- carbon potential and its geologically important posi- tion near the triple junction formed by the East Anatolian Fault, Dead Sea Transform Fault and Bitlis Suture (S ¸engör & Yılmaz, 1981). The stratigraphy of this basin was initially documented by Ternek (1957) and Schmidt (1961), and later revised by many work- ers (e.g. S. I ˙ lker, unpub. data, 1975; Gürbüz, Gökçen & Gökçen, 1985; Yetis ¸, 1988). Detailed facies analyses appeared after the mid-1970s (Görür, 1979, 1985; Yalçın & Görür, 1983; Gürbüz & Kelling, 1993; Yetis ¸ & Taner, 1987; Naz, Çuhadar & Yeniay, 1991) and focused mostly on the lower part of the basin fill, rang- ing from continental clastics to deep sea fans. A later wave of research was principally concerned with palaeogeography and basin evolution at both local and regional scales, with special emphasis on the geo- dynamic mechanisms responsible for initiation and evolution of the basin (Kelling et al. 1987; Akay & Uysal, 1988; Gökçen et al. 1988; Karig & Kozlu, 1990; Görür, 1992; Ünlügenç, Williams & Kelling, 1992; Williams et al. 1995; ITU, 1998; Dhont, Chorowicz & Yürür, 1999). Although extensional tectonic processes are generally implicated, the precise driving mecha- nism is still poorly understood. Hypotheses suggested range from a peripheral foreland basin setting to triple junction-determined depression, but more field-based studies are needed to validate the most appropriate model. Geol. Mag. 139 (4), 2002, pp. 473–487. © 2002 Cambridge University Press 473 DOI: 10.1017/S0016756802006544 Printed in the United Kingdom Palaeoenvironmental analysis of a Miocene basin in the high Taurus Mountains (southern Turkey) and its palaeogeographical and structural significance F. OCAKOG ˇ LU* Osmangazi University, Department of Geological Engineering, 26030 Bademlik, Eskis ¸ehir, Turkey (Received 28 February 2001; accepted 15 January 2002) Abstract – Determination of the relationships between the southern, marine-dominated Miocene basins of south central Turkey and their continental hinterland in southern Turkey has traditionally been frustrated by the apparent absence of basin remnants within the Taurus Mountains. The Dikme basin, which seems to be an enclave of basin remnants within the Aladag ˇ Mountains (Eastern Taurides), consists mainly of coarse-grained continental sediments of various facies. These mostly early–middle Miocene sediments were studied to determine the depositional environments and the factors controlling the basin formation and basin fill architecture, to attempt to close the information gap between the Adana Basin to the south and central Anatolian Miocene further to the north. A gen- erally southwest-flowing axial fluvial system and interfingering coarse-grained marginal alluvial clas- tics derived from northwest and southeast were identified. The marginal facies to the northwest is bounded by a N 55° E-running structural lineament, that starts from the Ecemis ¸ Fault Zone and in digital elevation models extends toward the north of the study area. Along this lineament, Miocene sediments onlap steep fault-line escarpments. Certain Miocene levels are tectonically disrupted, and an intraformational unconformity and boulder conglomerates are also well-developed in the Miocene sequence. The southeast boundary is similarly defined by a NE-trending fault that periodically ele- vated the adjacent Tufanbeyli autochthon, producing coarse clastics from this area. This boundary fault also induced fining-upwards vertical patterns and synsedimentary deformation in the marginal facies. Additionally, the central part of the basin exhibits a distinct fault-defined morphology charac- terized by small-scale (tens of metres to 150 m high) valley-and-sill topography. A thin marine interval was also encountered in the southernmost part of the basin, indicating that the clastic system originat- ing around this area debouched into a Miocene sea situated further to the south. The proposed palaeo- geography and basin fill model suggests that the Dikme basin and similar Miocene remnants, all controlled mainly by a northeast-running extensional or transtensional fault system, may have been parts of the terrestrial hinterland that supplied sediment to rapidly subsiding marine areas further south, such as the Adana Basin. Keywords: Adana Turkey; Miocene; extension tectonics; depositional fault; palaeogeography. * E-mail: focak@ogu.edu.tr