CAJ | 학술논문

An international cooperative study of the Late Cretaceous biota and non-marine strata including the Cretaceous-Paleogene (K-Pg) boundary in Jiayin near the Heilongjiang River,China during 2002-2010,is summarized in this paper.The strata includes the Upper Cretaceous Yong'ancun-,Taipinglinchang-,Yuliang zi-,and Furao formations,and the Paleocence Wuyun Formation consisting of Baoshantou Member and a Coal bearing Member.Seven palynological assemblages from Santonian to Paleocene are recognized,which is used for definition of the K-Pg boundary.Through the palynological analysis of three drilled boreholes ( XHY-2005,2006,2008 ) in Xiaoheyan of western Jiayin,the K-Pg boundary is defined within 20.00-20.05 m in the borehole XHY-2006 (as a standard boundary) which is just between the top of Furao Formation (late Maasterichtian) and the base of Baishantou Member (early Danian).These new research results are supported by paleomagnetic,geochemical and other analyses,also.On the other hand,the presence of eight taxa of Maasterichtian dinosaurs (mostly hadrosaurids) have been recognized by the authors; and two mega-plant assemblages from the Yong'ancun Fm (Santonian) to Taipinglinchang Fm (Campanian) are confirmed.These research achievements indicate that the Upper Cretaceous- Paleocene in Jiayin can be well correlated to the strata in the neighboring Zeya-Bureja basin,Russia.The K-Pg boundary definited in Jiayin is the first well documented non-marine K-Pg boundary in China.Also the related paleoclimate,paleoenvironment and the mass extinctions in this area during the Cretaceous-Paleocene transition are also discussed.