Multi-dimensional scaling of detrital zircon geochronology constrains basin evolution of the late Mesoproterozoic Paranoá Group, central Brazil

Abstract

Some of Proterozoic basin data are commonly difficult to assess due to the complexity of tectonic processes and lack of volcanic rocks and fossil record. The Mesoproterozoic Paranoá Basin in Central Brazil was investigated through stratigraphic framework integration, depositional environmental analysis and with detrital zircon and statistical analysis. Paranoá Group was evolved in three phases: i) Proto-Basin Stage represents the basal succession, including the transition from the continental environment (alluvial fans) to shallow water platform conditions; ii) Expansion Basin Stage, which includes the most significant sediment thickness and the essential contrasting depositional environment, including tide-dominated platform, storm dominated platform, supratidal and foreshore conditions and iii) Final Basin Stage represents the shallower environment condition, including mix siliciclastic – carbonate successions. The stages are related to different depositional space creation mechanisms: mechanical subsidence to the Proto-Basin Stage, thermo-flexural subsidence to the Expansion Basin Stage, and flexural subsidence to the Final Basin Stage. The detrital zircon data allied with multidimensional scale were crucial to constrain the basin's tectonic evolution. For the basal succession, the maximum depositional age is ∼1.5 Ga with the local crystalline basement (Aurumina Suite tonalitic and granodioritic gneiss). The source areas changed during the expansion stage, in which the sedimentary successions accumulated during this stage present maximum depositional age of ∼1.3 Ga and a widespread distribution pattern. In the final phase, the maximum depositional age is ∼1.1 Ga, including a complex distribution of ages representative of different source areas. The new and compiled data presented in this study provide new insights about the Goiás-Pharusian opening and implications on the configuration in the western margin of the São Francisco Craton.