Seminar

Establishing the robust ages for fossils will allow to calibrate biological events in the Earth history. Here I present two classic examples how we apply geochronology in Mesozoic key events. First, my study provides the age determination for the oldest-known in-situ preserved amber in China. Amber is a fossilized botanic resin of conifer and broad-leaved trees ranging from a few millions to more than 300 million years in age. There are more than 1000 amber localities in the world, but very few have been found in China. Collaborating with paleontologists, I discovered a new amber site from two coal mines at the Hailar Basin of Inner Mongolia, northeast China. To establish robust age for this significant site and provide important constraints on the biogeographic history of the field area, I collected datable samples from two mines for LA-ICPMS U-Pb dating. Our preliminary data show that the maximum depositional ages for these two distinctive mines are 111.7 ± 2.2Ma and 130.9 ± 2.8 Ma, respectively. The result has pushed back the oldest amber site found in China to early Cretaceous. Second, I aim to establish high-precision age for the fossil-rich Reshuitang beds in western Liaoning, northeast China. This less-studied outcrop yields abundant well-preserved fossils from Mesozoic volcano-sedimentary deposits. The biostratigraphic correlation between the Reshuitang fossil beds and the nearby Daohugou fossil beds is still not very clear. This research will focus on the age constrain of the Reshuitang fossils, mainly including salamanders and insects. This study will also clarify the biostratigraphic correlation between Reshuitang and the famous Daohugou.