Sedimentology of a Late Cenozoic collisional sequence: the Misis Complex, Adana, southern Turkey

Abstract

This study is concerned with Miocene sequences formed within part of the Cukurova Basin of southern Turkey, a major downwarp created during the early stages of collision between the Afro-Arabian plate and the Tauride-Anatolian microplate assemblage. We report here the results of a combined stratigraphical, sedimentological, structure and geochemical study of the Misis Complex, a structurally elevated segment of Cukurova basin-fill. This analysis has demonstrated the structurally imbricated nature of the Misis sequences and the tectonic juxtaposition of originally well-separated coeval facies. The initial discernible phase of basin-filling (pre-Burdigalian) was marked by deep marine conditions and marginal tectonic instability (probably related to a late phase of Tauride nappe advance). The subsequent phase of crustal extension (Burdigalian/Early Tortonian) produced expansion of the Cukurova basin limits and an upwards-shoaling succession, in which sediment transport towards the southwest gradually became dominant, as a result of earlier suturing and uplift in northeasterly sectors of the collision zone. The Miocene arenites of the Misis Complex are petrographically diverse (with common siliciclastic and carbonate detrital admixtures) and mineralogically immature and their position in petrotectonic fields indicates a compound provenance from both recycled orogen and magmatic arc sources. A noteworthy petrographic feature is the compositional similarity of arenites from both shallow and deep marine facies. The general succession of Neogene facies observed in the Cukurova Basin and Misis Complex is consistent with their evolution within a perisutural foreland basin, but this interpretation is complicated by petrographic and geochemical features attributed to remnants of an older magmatic arc. Later stages of basin-filling are also marked by the local occurrence of “anomalous” palaeoenvironmental associations (including olistostromic units) attributed to contemporaneous intra-basinal tectonism.