(U-Th)/He geochronology of supergene iron ores from Attepe, Eastern Taurides, Türkiye: Evidence for early Pleistocene aridification

The Taurus Mountains form the southern boundary of the Central Anatolian Plateau in Türkiye and represent part of the broader Himalayan-Tibetan orogenic system. Today, they act as a climatic divide, separating the dry, semi-arid interior to the north from the more temperate Mediterranean climate to the south. However, their formation history and climatic impacts remain unclear. In this study, we apply multiple aliquot (U-Th)/He dating to supergene iron-oxide phases from the Attepe iron deposits in the Eastern Taurides to investigate Cenozoic climatic conditions. The ages obtained from four deposits range from ~5.2 to 0.95 Ma, indicating sustained hot and humid conditions conductive to supergene mineralization during the Plio-Pleistocene. The observed decrease in age with depth, reflect a progressive deepening of the weathering front at rates of 6.4 to 18 meters per million years between 5 and 1 Ma. The preservation of supergene iron minerals formed during a stable, warm, and humid period between the late Miocene and middle Pliocene implies an absence of rapid uplift or erosion within the past million years. Instead, the youngest goethite around 0.95 Ma supports the hypothesis that regional climate change, rather than tectonic uplift, was the primary factor of increasing aridity around ~1 Ma.