"Baby Louie" dinosaur fossil embryo, located at the bottom of Upper Cretaceous Gaogou Formation in Xixia Basin, was excavated from Zhaoying Village of Yangcheng Township in Xixia County of Nanyang City, Henan Province. Upper Cretaceous strata of Xixia Basin can be divided from bottom to top into Gaogou Formation, Majiacun Formation and Sigou Formation. "Baby Louie"is embryonic skeleton fossil of Macroelongatoolithus xixaensis. Gaogou Formation is rich in dinosaur egg fossils and little dino?saur bone fossils as well as a few fossil fragments of bivalve, gastropods, Ostracods, Charophyceae, plant pollen, and plant fossil togeth?er with abundant trace fossils. According to geological age of fossils in combination with conformable contact between Majiacun For?mation and Gaogou Formation as well as fossil assemblage of Sigou Formation, angular contact between Gaogou Formation and Low?er Devonian Nanwan Formation and stratigraphic correlation with surrounding basin layers, the authors hold that geological epoch of Gaogou Formation in Xixia Basin should be Late Cretaceous Coniacian. The lower and middle Gaogou Formation seems to be terrig? enous clastic rocks of semi-arid red continental type molasse-like formation belonging to alluvial fan and braided river sedimentation of intermittent muddy waters, whereas the upper part of Gaogou Formation seems to be alluvial fan and traction current deposit. The horizontal paleo-geographic environment of"Baby Louie"is flat and wide alluvial fan facing south at the alluvial end, which can be classified as alluvial fan facies-fan end subfacies-flowing microfacies.

本文对河南济源盆地大峪槐疙瘩岭二叠系上石盒子组(P3sh)、孙家沟组(P3s)和三叠系刘家沟组(T1l)剖面岩石样品进行了元素、频率磁化率、碳酸盐以及总有机质等的分析研究,结果表明在二叠系孙家沟组(P3s)底部济源动物群化石层、以及三叠系刘家沟组(T1l)底部界线(P/T)附近,其微量和常量元素发生了较明显的变化.化石层中Ba,Cr,Hf,Nb,Th,Ti,V,Y,T1,Zn,Cu,Ga,Pb,Ni,La,Rb,Nd,以及K2O,Al2O3,Fe2 O3含量相对较高,Zr,W,Sr,Bi,Co,Ce,以及SiO2,Na2O含量较低,MgO,CaO,Mn则没有明显的变化.Ba,Hf,Nb,Th,Ti,V,Y,W,K2O,Al2 O3,SiO2,Na2O,Bi,Fe2O3,Ni,Co,La,Nd,Ce,及有机碳含量在三叠系底部含量明显上升,Cu,Ga,Pb,Tl,Zn,Cr,Zr,Sr,MgO,CaO,以及岩石频率磁化率Xfd、碳酸盐含量则明显下降.该剖面不仅记录了二叠—三叠纪的生物灭绝事件,而且有明显的二叠三叠系界线,事件及界线的形成可能与沉积环境和古气候有关,水体的变浅、炎热气候和风化作用加强可能是直接的原因.石盒子组(P3sh)主要为河流—三角洲沉积环境,古气候相对温暖湿润;孙家沟组(P3s)为三角洲平原相,前期和后期有强烈风化作用,并且炎热多雨.中期则水平面上升,水下三角洲前缘砂质沉积为主;三叠系刘家沟组(T1l)则水体进一步扩张,气温相对下降.

河南汝阳盆地上东沟组和郝岭组的腹足类主要由个体微小的Mesocochliopa,Scaevicochlea,Bithynia,Proauricula,Zaptychius,Physa,Gyraulus,Pseudarinia和口盖化石Reesidella multilaminate xiazhuangensis Pan and Zhu等组成,其中,Bithynia个体相对稍大,Gyraulus和口盖化石个体最为丰富.该腹足类动物群与北京西山的夏庄组,辽宁阜新的阜新组和内蒙古潮水盆地庙沟群的腹足类动物群很相似,应归入Mesocoshliopa cretacea-Zaptychius costatus-口盖化石Reesidella multilaminate xiazhuangensis Pan and Zhu种群中,其时代为早白垩世(Aptian-Albian期).该腹足类动物群可能栖息于泥底而且水体很浅的河漫滩和河边水潭环境中.

The Ruyang Basin is a Mesozoic—Cenozoic basin in western Henan Province.The clastic rock series overlapping the Jiudian Formation in the Ruyang Basin had been divided into the Paleogene Chenzhaigou Formation,Mangchuan Formation and Shitaijie Formation by geologists.Due to the discovery of Ruyang Giantic Sauropod DinosaurianFauna in the original Mangchuan Formation in 2006,it is necessary to restudy the clastic rock series.On the basis of large-scale geological mapping,section measuring,collecting fossils of invertebrates,microbiota and vertebrates,and samples of radioactive isotopes dating,stable isotopes,geochemistry,as well as rock slices in this area,we conclude that the clastic rock series distributed in central part of the Ruyang Basin(Shangdian—Liudian Area),the original Chenzhaigou Formation and Mangchuan Ormation should be dated to the Cretaceous.This paper suggests that the Cretaceous Xiahedong Formation,HaoLing Formation and Donggou Formation represent the dinosaur-bearing clastic rock series.

Recently,lots of dinosaurs found from the originally named Paleogene Mangchuan Formation of the Ruyang Basin of Henan Province form a distinct dinosaurian fauna. It is dominated by plant-eating gigantic to large-sized sauropods, accompanying with small theropods, and hadrosaurids. The preliminary study indicates that at least 10 kinds of new dinosaurs and lots of dinosaur egg fragments, turtles, bivalves and fossil plants have been discovered.It was called the Ruyang Gigantic Sauropod Dinosaurian Fauna by L et al.. It represents a new late Early Cretaceous to early Late Cretaceous dinosaurian fauna from China. The diversity of sauropods is much higher than the previously thought. Based on microfossil assemblage features, such as charophyta, ostracods and spores and pollens, stratum characters and regional correlation, the geological age of the dinosaur-bearing Mangchuan Formation from the Ruyang Basin is regarded to belong to mid—late Early Cretaceous. Undoubtedly, the originally assigned Eocene Chenzhaigou Formation and Mangchuan Formations of the Ruyang Basin should be long to Cretaceous, however, this still needs evidence to decide whether it belongs to mid—late Early Cretaceous or early Late Cretaceous.