Reconstructing the Thermal History of the Morondava Basin, Madagascar During Gondwana Breakup: A Detrital Zircon (U-Th)/He and U-Pb Study

Abstract

The Morondava Basin is one of three Phanerozoic rift basins bordering the western coast of Madagascar. Sediments were first deposited in this basin during the initial stages of breakup of Gondwana in the Permian, sourced from the adjacent Precambrian basement terranes. Gondwana breakup resulted in several stages of subsidence, tilting, and uplift of Madagascar, the thermal history of which is recorded within the strata of the Morondava Basin. We have applied U-Pb detrital zircon techniques to investigating the sedimentation and transport patterns of Jurassic and Cretaceous strata. In order to reconstruct the thermal history of the Morondava Basin throughout the stages of rift basin development we have applied modelling of (U-Th)/He thermochronology data. Our models show a protracted cooling history influenced by multiple stages of uplift and subsidence occurring differentially across the basin. A furthered understanding of the Morondava Basin with respect to its development during Gondwana breakup has implications for oil exploration in the region.