A Fossil Morphology: The Miocene Fluvial Network of the Western Taurus (Turkey)

Abstract

Lower Miocene conglomerates in the Köprü and Manavgat basins contain pebbles that can be confidently traced back to their source areas, owing to their distinctive lithologies. Among others, are the green Hu¤lu volcanics (Late Trias), known only in allochthonous units from the Beyflehir region, or the Alanya blueschists, restricted to the Sugözü unit in the Alanya Massif. The problem is to find out how this detrital material could have travelled about eighty kilometres through the Taurus calcareous units during the Miocene. Fortunately, the present drainage system is not yet fully reorganised in the Taurus, and large areas of the chain still retain fossil morphologies. These may be seen in the upper karstic areas of the chain, where a large part of a high surface (1500-2200 m) is preserved. On this surface several dry valleys, some of them 400 m deep, with meanders and tributaries, have been recognised. They are disconnected from the present drainage, and represent fragments of a former network directed NE-SW, at right angles to the structures of the Taurus chain. The age of this network may be attributed indirectly to the Early Miocene. On the other hand, the presence of blueschist fragments in conglomerates of the Aksu Basin cannot be explained through a NE-SW-directed drainage system, and implies instead that the Alanya Massif extends to the west below the Miocene cover of the Antalya Gulf. Later, Late Miocene faulting fragmented the high surface and disrupted the drainage system. Uplift of the Taurus chain followed in the Pliocene and Quaternary, and is responsible for the extensive karstic circulation seen today, which left aside remnants of the ancient morphology of the chain.

Monoclinal flexure of an orogenic plateau margin during subduction, south Turkey

“…These marine sediments belong to the Mut Basin and are coeval with fluvio‐lacustrine deposits known from seismics for the Tuz Gölü area farther north (Fernández‐Blanco, Bertotti, & Çiner, ; Görür, Oktay, Seymen, & Sengör, ; Huvaz, ). Rocks in both the areas are in turn unconformably covered by terrace and alluvial fan Pliocene to Quaternary continental deposits (Monod, Kuzucuoğlu, & Okay, ; Özsayin et al, ) (Figure ‐ section a). Miocene rocks in the southern margin of the Mut Basin may shape a monocline on top of the basement, with a roughly flat surface in the hinterland that progresses into gently south‐dipping geometries in its southward offshore continuation (Figure ‐ section b; Fig.…”

Thermal history of the western Central Taurides fold-thrust belt: Implications for Cenozoic vertical motions of southern Central Anatolia

“…The widespread deposition of the Oymapınar limestone in the Antalya Basin in earliest Miocene time demonstrates that there was essentially no siliciclastic sediment production related to the erosion of the Bozkır and Aladağ nappes at that time. From early Miocene to Pliocene times, deposition of the siliciclastic Karpuzçay Formation, which included pebbles derived from the Bozkır nappes (Monod and Kuzucuoğlu, 2019), required an east-to-west-flowing paleodrainage system. This drainage system may be preserved as valleys that cut across the NW-SE structures of the Taurides (Monod et al, 2006).…”

“…From early Miocene to Pliocene times, deposition of the siliciclastic Karpuzçay Formation, which included pebbles derived from the Bozkır nappes (Monod and Kuzucuoğlu, 2019), required an east-to-west-flowing paleodrainage system. This drainage system may be preserved as valleys that cut across the NW-SE structures of the Taurides (Monod et al, 2006). Widespread early Miocene cooling ages, as well as increased rates of cooling recorded in samples KOP-6 and possibly KIRK-1 (plus BA-1), likely record erosional exhumation related to the early development of this Miocene-Pliocene drainage system.…”

“…20-14 Ma) Oymapınar Limestone Formation, which in places covers a basal conglomerate of an undetermined age (Karabiyikoğlu et al, 2000;Deynoux et al, 2005). The basal conglomerate contains pebbles that are likely derived from the Bozkır nappes that form the highest structural unit of the Taurides (Monod and Kuzucuoğlu, 2019). The drainage system that delivered those pebbles may be preserved as abandoned paleovalleys that cut into a low-relief surface defined by mountain peaks, which has an inferred early Miocene age, based on lower Miocene sediments that may be associated with them (Monod et al, 2006).…”

“…The basal conglomerate contains pebbles that are likely derived from the Bozkır nappes that form the highest structural unit of the Taurides (Monod and Kuzucuoğlu, 2019). The drainage system that delivered those pebbles may be preserved as abandoned paleovalleys that cut into a low-relief surface defined by mountain peaks, which has an inferred early Miocene age, based on lower Miocene sediments that may be associated with them (Monod et al, 2006). The conglomerates fill a paleo-topography and form fans that were deposited in subaerial to shallow marine conditions (Karabiyikoğlu et al, 2000).…”