Record of the Late Paleozoic Ice Age From Tarim, China

Abstract

Abstract The late Paleozoic ice age was one of the three major glaciations in the Phanerozoic. However, the influence and characteristics of this glaciation and deglaciation remain unclear. In this study, we present lithostratigraphy, biostratigraphy, and chemostratigraphy during the Late Mississippian to the Early Permian in Tarim, Northwestern China. Tarim records two Gondwana glacial events in the Serpukhovian‐Moscovian (Glacial II) and the Asselian‐Sakmarian (Glacial III). Together with the global evidence of isotopes and sea level changes, multipulsed growth and decay of Glacial II and III are confirmed. The Serpukhovian isotopic pattern in Tarim exhibits a negative δ13C excursion of −6.6‰, which is comparable to those recorded in other continents. This negative excursion and contemporaneous sea level fall are triggered by the expansion of the ice sheets of Glacial II. The glaciation maximum is marked by the global sea level fall during the Bashkirian. A two‐stage transgression and positive shifts of δ13C from the Tarim and Laurussia represent evidence of stepwise deglaciation of Glacial II during the Moscovian. Positive δ18O excursions in Tarim and other two global sections from Laurussia and the regression during early Asselian to early Sakmarian are linked to the Glacial III, confirming this event is of global origin. The eustatic rise and the negative δ18O shifts indicate the retreat of this Gondwana glacier in late Sakmarian. These continuous data sets in Tarim coupled with time equivalent stratigraphy and geochemical records provide insights into the multistage evolution of the discrete Glacial II and III events.

Keywords

• Carbon isotope
• Oxygen isotope
• Chemostratigraphy
• Late Paleozoic Ice Age
• Tarim