Reconstructing Early Pleistocene (1.3Ma) terrestrial environmental change in western Anatolia: Did it drive fluvial terrace formation?

A terrestrial environmental reconstruction of an Early Pleistocene landscape from western Anatolia is presented. The basis of this reconstruction is a sedimentary stack comprising fluvial and colluvial slope deposits. Contained within this stack is a sequence comprising two massive laminar calcretes alternating with three reddish palaeosols. This evolutionary sequence is situated on top of a fluvial terrace staircase capped by a 1.3Ma (⁴⁰Ar/³⁹Ar plateau age) lava flow. The micro-morphological properties of the observed calcretes and reddish palaeosols combined with the stable oxygen and carbon isotopic composition of the carbonates suggest the alternation of three stable relatively warm-humid (vegetation rich) and two stable relatively arid-cool (bare surface) cycles. In addition, there is also ample evidence for landscape instability in between these phases causing local soil truncation and slope instability in an open grassland-shrub environment. These landscape instability phases match well with known fluvial incisional phases of the Gediz during this period. This suggests that climate-forced landscape environmental dynamics were of sufficient magnitude to drive fluvial terrace formation of the Early Pleistocene Gediz.