Compositional and mineralogical variations in a Neoproterozoic glacially influenced succession Mirbat area south Oman: Implications for paleoweathering conditions

摘要: Abstract During the late Neoproterozoic Era Earth is believed to have experienced some of most severe climatic oscillations in geological history. The Mirbat Group southern Oman comprises a continuous succession sedimentary rocks containing two (Cryogenian) glacial intervals separated by ∼1 km non-glacial marine deposits. We show that variations major element and mineralogical compositions mudstones from (Ayn Formation) (Arkahawl Marsham Formations) are best explained terms effects chemical paleoweathering contemporary land surfaces. Chemical weathering was at very low levels during deposition glacigenic Ayn Formation, whereas intense recorded thick, Arkahawl Formations. Paleoweathering corroborated sedimentological evidence paleoenvironments attributed changes dry cool glaciations humid warm long interlude.