Provenance of the Eocene sandstones in the southern Chindwin Basin, Myanmar: Implications for the unroofing history of the Cretaceous–Eocene magmatic arc

摘要: Abstract The Eocene sedimentary rocks, exposed in the southern Chindwin Basin, northern part of Myanmar, are characterized by a thick sequence continental clastic units consisting sandstones with abundant volcaniclastic materials, and subordinate amount metamorphic lithic fragments. Detrital information preserved these sequences has shed light on erosional unroofing history Cretaceous to Andean-type magmatic arc related India–Asia collision. An integrated study petrography, geochemistry LA-ICP-MS (Laser Ablation Inductively Couple Plasma Mass Spectrometer) U–Pb zircon geochronology late Middle Eocene, Pondaung sandstones, combined WSW-directed regional mean palaeocurrent direction (∼254° azimuth), revealed an older, calc-alkaline, andesitic volcanic (detrital age: 101–43 Ma), situated NE possibly Neo-Tethys seafloor subduction beneath Eurasia margin, i.e., West Burma Block or (Myanmar) Plate. We suggest that this may have been eroded during (Bartonian) detritus deposited fore-arc basin Central Myanmar forming Formation.