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Timing of the Jiufotang Formation (Jehol Group) in Liaoning, northeastern China, and its implications
Author(s) -
He H. Y.,
Wang X. L.,
Zhou Z. H.,
Wang F.,
Boven A.,
Shi G. H.,
Zhu R. X.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl019790
Subject(s) - geology , aptian , sanidine , yixian formation , zircon , paleontology , cretaceous , geochemistry , biotite , mesozoic , structural basin , quartz
The timing of the Jiufotang Formation remains speculative despite recent progress in the study of the Jehol Biota. In this paper we contribute to this topic with 40 Ar/ 39 Ar dating on K‐feldspar (sanidine and orthoclase) from tuffs interbedded within the fossil‐bearing shales of the Jiufotang Formation, from the upper part of the Jehol Group in Chaoyang, Liaoning, northeastern China. 40 Ar/ 39 Ar step heating analyses of K‐feldspar and the SHRIMP U‐Pb zircon data indicate that tuffs at the Shangheshou section erupted at 120.3 ± 0.7 million years ago. This result confirms an Aptian age for the Jiufotang Formation that was mainly based on biostratigraphic evidence. It also places stringent controls on the age of the fossils from the formation, providing a minimum age (120 Ma) for the four‐winged dinosaur, Microraptor , and the seed‐eating bird, Jeholornis .