Sequence stratigraphy of the Mesozoic Domeyko Basin, northern Chile

Abstract

The Domeyko Basin of northern Chile records Late Triassic to Early Cretaceous mixed carbonate and siliciclastic marine deposition along the western margin of Gondwana. Sequence stratigraphical analysis has identified five long-term sequences of 11–17 Ma duration. Comparison of the relative sea-level fluctuations interpreted from the Domeyko Basin succession with those documented from other similar-aged South American marginal basins and northern hemisphere basins allows the distinction of regional from global events. Relative sea-level fall in the Early Pliensbachian, Early Aalenian and Early Valanginian, and rises in the Early Hettangian, Early and Late Toarcian, Early and Late Bajocian, Late Bathonian and Early Oxfordian of the Domeyko Basin appear time-equivalent to similar events in other southern and northern hemisphere basins and are thus interpreted to be products of global sea-level cycles. Long-term relative sea-level falls in the Early Bathonian, Late Oxfordian, Early Valanginian and rise in the Late Kimmeridgian are interpreted to be tectonically driven, continental-scale changes in sediment-accommodation space. The Domeyko Basin succession thus appears to have been dominantly controlled by global sea-level fluctuations during the Early to Mid-Jurassic and by continental-scale (but not global) fluctuations during the Mid-Jurassic to Mid-Cretaceous, interpreted to have been driven by the fragmentation of Gondwana.