Oil preserved in fluid inclusions in Archaean sandstones

摘要: Oil is generally thought to be geologically young, as it thermodynamically unstable when subjected elevated temperatures over long periods in open systems1,2. Indeed, almost all petroleum production comes from rocks younger than 400 million years (ref. 3). Although the oldest known oil occurs 1,650 Myr old4, suitable source were abundant older geological successions5 and circumstantial evidence suggests that some of these generated hydrocarbons early their history6. Here, we report discovery preserved fluid inclusions sandstones dating back ∼3,000 Myr. Most lie within healed microfractures confined individual detrital quartz grains, indicating was emplaced before Archaean or Palaeoproterozoic metamorphism sealed voids thus came (in cases Archaean) sources. The apparently acted inert pressure vessels protected subsequent degradation by circulating fluids mineral catalysts. Because its great age, this can potentially yield valuable information about size diversity biosphere, particularly if contains molecular fossils (biomarkers) primordial organisms which derived.