Fluorescent Growth Bands in Irradiated-Bitumen Nodules: Evidence of Episodic Hydrocarbon Migration

摘要: Minute rims of solid bitumen (~40-50 µm thick) surround detrital radioactive grains in the Permian-Triassic sandstones and Arranoo Member Kockatea Shale from northern Perth basin, Australia. The formed as Th- U-bearing minerals (monazite, xenotime, zircon, thorite) irradiated immobilized fluid hydrocarbons coming within range alpha-particle emissions. Using transmitted light scanning electron microscopy appear compositionally homogeneous, but under blue/violet epifluorescent illumination displays complex concentric contorted banding. These fluorescent textures indicate that multiple influxes passed through reservoir sandstones. Following radiation-induced immobilization first oil influx, nodules grew a process swelling expansion outward mineral core during subsequent