Sedimentary rocks record a wealth of information on the evolution of lithosphere, hydrosphere, atmosphere and biosphere. However, uncertainty about the age of many Precambrian sequences makes it very difficult to establish the accurate temporal framework which can dramatically improve our understanding of the scale and duration of geological and biological events. The Neoproterozoic Doushantuo Formation, South China, preserve unique assemblages of early multicellular fossils and records valuable paleoenvironmental information. The age of these formations is thus critical for understanding the important biological and climatic events that occurred towards the end of the Proterozoic Eon. In this study, we used NanoSIMS to date samples from the Doushantuo Formations by apatite U-Pb geochronology. Fossil-associated precipitated apatite grains were identified using optical microscope and Raman spectrometer. The resultant age is 305 ± 26 Ma. High common Pb and low U concentration in those apatite specimens limit the precision of age determination, while the yielded age suggests that the Doushantuo Formation may have experience a post-depositional hydrothermal event.
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology