December 25 , 2016:

In order to determine the dinosaur skeleton and egg fossil strata in the Tiantai Basin, Tiantai County, Zhejiang Province, crystaline tuff interlayers were selected in the red beds of the Laijia Formation and Chichengshan Formation where dinosaur bones and egg fossils were present, with precise zircon SHRIMP and LA-ICP-MS U-Pb dating. The results show that the diagenetic ages of the upper and lower Chacheng tuffs are 100 ± 1 Ma and 92 ± 1 Ma, respectively, indicating that the Laijia Formation was deposited in the Late Cretaceous to Early Cretaceous, while the Chichengshan Formation was formed in the Late Cretaceous, and the continuous deposition of the two groups formed the stratum of dinosaur skeleton and egg fossil in the Tiantai Basin. It is inferred that the formation age of the lower Tong Formation in the integrated contact with Laijia Formation is earlier (> 100 Ma) in the Late Cretaceous, while the dinosaur extinction in the Tiantai basin was later than that in the Late Cretaceous (<92 Ma). The above results can also be used to carry out stratigraphic correlation between Tiantai Basin and other eastern basins.

Jiang Yang, Qian Maiping, Xing Guangfu & Jiang Yangen (2016)
Zircon U-Pb chronology of dinosaur skeleton and egg fossil strata in the Tiantai Basin, Zhejiang Province.
Journal of Stratigraphy 2016 3: 272-277 (in Chinese)