Pleistocene aridification of the Eastern Taurides, Turkey revealed by
(U-Th)/He ages of supergene mineralisation in Attepe iron deposits.
Abstract
The Taurus Mountains form the southern margin of the Central Anatolian
Plateau of Turkey and form an orographic barrier separating the cold,
semi-arid interior to the north from the mild Mediterranean coast to the
south. When and how they formed, and the extent which they have
influenced the regional climate remains poorly constrained. The Attepe
iron deposits sit on the northern part of the Eastern Taurus mountains
at altitude of 1.5-2 km and consequently are ideally located to record
interactions between climate and tectonics. (U-Th)/He ages of
iron-oxide-oxyhydroxides from four mines within the Attepe iron deposits
record ages of 1-5 Ma consistent with the persistence of hot humid
climate conditions throughout the Pliocene and Pleistocene. In mines
where samples are measured from different depths the age data are
consistent with water table lowering rate of between 12.3 to 6.4 m/Myr.
Translating these to rock uplift rates they are close to uplift/incision
recorded within the Central Anatolian Plateau over the past 2 Ma,
suggesting that the region was already at or close to its current
elevation by the late Miocene. The latest goethite precipitation
constrains the cessation of hot-humid climate to sometime in the last
million years and implies that regional climate cooling, rather than
surface uplift, was the main driver of aridification.