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middle jurassic palynomorphs of the Dalichai Formation, central Alborz Ranges, northeastern Iran:Paleoecological inferences

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Science China Earth Sciences 2013年第12期56卷 2107-2115页

作者： DEHBOZORGI Afsaneh SAJJADI Freshteh HASHEMI Hossein Faculty of Geology College of ScienceUniversity of TehranEnghelab AvenueTehran 14155-6455Iran Department of Geology Faculty of Science and Research School of Applied SciencesKharazmi UniversityNo. 49Mofatteh AvenueTehran 15614Iran

Palynological data are used to draw paleoecological inferences for the Dalichai Formation,northeast of Semnan,northeastern *** samples examined yield well-preserved,diverse palynofloras consisting predominantly of miospores;dinoflagellate cysts,foraminiferal test linings,and fungal spores occur as minor ***-four species of spores(37 genera),18species of pollen(9 genera),and 16 species of dinoflagellate cysts(13 genera)are ***-occurrence of such miospore species with known vertical ranges as Klukisporites variegatus,Sellaspora asperata,Murospora florida,and Concavissimisporites verrucosus suggests a middle jurassic(Bajocian-Callovian)age for the host strata,thus corroborating the available paleozoological *** spore species as Klukisporites,Cyathidites,and Dictyophyllidites known to have been produced by Pterophyta dominate the *** the contemporaneous coastal vegetation was characterized by predominance of Pterophyta whereas representatives of Ginkgophyta,Pteridospermophyta,Lycophyta,Coniferophyta,and Bryophyta were rarely *** reconstruction implies that a moist,warm climate prevailed in northeastern Iran during the middle jurassic(Bajocian-Callovian).This is confirmed by occurrence of fungal spores accompanied by such warm water dinoflagellate cysts as Mendicodinium groenlandicum,Pareodinia ceratophora,and Gonyaulacysta *** of Amorphous Organic Matter(AOM)signifies a shallow,low-energy,dysoxic-anoxic depositional site for the host ***,the ratio of AOM to marine palynomorphs as well as abundance of blade-shaped to eqiudimensional opaque palynomacerals could indicate low sedimentation rate in a shallow,low-oxygenated marine ***,occurrence of chorate dinoflagellate cysts(e.g.,Adnatosphaeridium caulleryi)and acritarchs bearing relatively long processes(e.g.,Micrhystridium)possibly suggests deepening upward in the study section.

关键词： palynomorphs middle jurassic paleoecology Alborz Ranges Dalichai Formation

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Net primary productivity and its control of the middle jurassic peatlands: An example from the southern Junggar coalfield

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Science China Earth Sciences 2018年第11期61卷 1633-1643页

作者： Yanan LI Longyi SHAO Zhiming YAN Haihai HOU Yue TANG David J.LARGE College of Geoscience and Surveying Engineering China University of Mining and Technology Oil and Gas Resources Survey Center China Geological Survey Administration Faculty of Engineering University of Nottingham

The jurassic is an important period of global coal formation, including the development of several large coalfields in central Asia and northern China. Individual seams within these peatlands represent sustained periods of terrestrial carbon accumulation and a key environmental indicator attributed to this record is the rate of carbon accumulation. Determining the rate of carbon accumulation requires a measure of time contained within the coal and this study aimed at determining the rate via the identification of Milankovitch orbital cycles using spectral analysis. Spectral analyses of geophysical data from two thick coal seams, No. 43(35.9 m) and No. 3(13.2 m), of the middle jurassic of the southern Junggar coalfield were conducted to identify significant signals of variations in ash content. The results showed that the variations in ash content of the coal showed spatial cycles at 0.2, 0.7 and 1.1 m^(-1), which were interpreted to represent 123 ka(eccentricity), 37.1 ka(obliquity), and 21.2 ka(precession) orbital periodicities, respectively. Using this timeframe, the depositional time of the No. 43 and No. 3 coal seams were calculated to be 876–970 and 322–357 ka, respectively. In combination with an understanding of carbon loss during coalification, the carbon accumulation rates of these middle jurassic peatlands were calculated to be 58.6–64.9 and60.3–66.8 g C m^(-2) a^(-1) for the No. 43 and No. 3 coal seams, respectively. Given that the net primary productivity(NPP) was 4.3 times the value of the carbon accumulation in a mid-latitude region of 40°–45°N, an NPP of 251.8–279.1 and259.1–287.1 g C m^(-2) a^(-1) was calculated for the No. 43 and No. 3 coal seams, respectively. In the context of the same paleolatitude(40°–45°N) and peat type, the NPP values of the middle jurassic strata in the study area were higher than those of the peatlands of the Holocene and Permian, and were similar to the NPP values of Early Cretaceous peatlands. Considering the NPP of a peat

关键词： Peatland middle jurassic Milankovitch cycle Net primary productivity Mid-latitude region Paleoclimate

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Lacustrine basin evolution and coal accumulation of the middle jurassic in the Saishiteng coalfield, northern Qaidam Basin, China

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Journal of Palaeogeography 2016年第3期5卷 205-220页

作者： Meng Li Long- Yi Shao Lei Liu Jing Lu Baruch Spiro Huai-Jun Wen Yong-Hong Li College of Geosciences and Survey Engineering China University of Mining and Technology Beijing 100083 China Institute of Resources and Environment Henan Polytechnic University Jiaozuo 454000 China Department of Mineralogy Natural History Museum London United Kingdom Qinghai Bureau of Coal Geological Exploration Xining 810000 China

Based on an extensive borehole survey of the middle jurassic coat-bearing sequences in the Saishiteng coalfield, northern Qaidam Basin （NQB）, a total of 20 rock types and 5 sedimentary facies were identified, including braided river, meandering river, braided delta, meandering river delta, and lacustrine facies. The distribution of rock types and sedimentary facies contributed to the reconstruction of three periods＇ sedimentary facies maps of the middle jurassic in the Saishiteng coalfield, namely, the Dameigou age, the early Shimengou age and the late Shimengou age. That also provided the basis for the development of a three-stage depositional model of the middle jurassic in the NQB, indicating the lacustrine basin of the NQB in the Dameigou age and early Shimengou age were corresponding to an overfill basin, and that in the late Shimengou age was related to a balanced-fill basin. The analysis of the stability and structure of coat seams based on sedimentary facies maps showed that the preferred coal-forming facies in the Saishiteng coalfield were inter-delta bay and interdistributary bay of lower delta plain in the Dameigou age. In particular, the swamps that developed on the subaqueous pataeohigh favored the development of thick coat seams. Thus, ruinable coal seams may also be found along the Pingtai pataeohigh in the western part of the Saishiteng coalfield.

关键词： Sedimentary facies middle jurassic Northern Qaidam Basin Lacustrine basin evolution Coalaccumulation

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A New Species of Ginkgo with Male Cones and Pollen Grains in situ from the middle jurassic of Eastern Xinjiang,China

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Acta Geologica Sinica(English Edition) 2017年第1期91卷 9-21页

作者： WANG Zixi SUN Fankai JIN Peihong CHEN Yingquan CHEN Jingwei DENG Peng YANG Guolin SUN Bainian School of Earth Sciences & Key Laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University Key Laboratory of Petroleum Resources Gansu ProvinceChinese Academy of Sciences

Well-preserved Ginkgo pollen organs are analyzed from the middle jurassic Xishanyao Formation of the Turpan–Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China, and are described as a new species, Ginkgo hamiensis Z.X. Wang et B.N. Sun sp. nov. The immature male cones are cylindrical and catkin-like, with two longitudinal stripes on the stalk. The pollen sacs are shaped like a long oval with two pollen sacs fused together for each microsporophyll, and the microsporophyll tip is a triangular cystidium. The pollen grains are oblong or fusiform and monocolpate; both ends are blunt or sharp. By comparison with previously reported fossil records of Ginkgo plants, we determined that the current fossils are different from all other reported species; thus, the present fossil is referred to as a new species of Ginkgo. The reproductive organs of the Ginkgo fossils described herein can provide valuable information for the study of Ginkgo plants. Further, there are two probable evolutionary trends in the Ginkgo pollen cones. One trend is that the number of pollen sacs changed from three or four during the jurassic and Cretaceous to two at the present day; the other is that the number of pollen sacs has remained two from the middle jurassic to the present day. In addition, the pollen cones described herein are similar to the pollen cones of the extant Ginkgo, which strongly indicates that the morphology of Ginkgo plants may have remained highly conserved over millions of years.

关键词： Ginkgo hamiensis Pollen cones middle jurassic Xinjiang Uygur Autonomous Region Systematic evolution

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Repeated Wildfires in the middle jurassic Xishanyao Formation(Aalenian and Bajocian Ages) in Northwestern China

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Acta Geologica Sinica(English Edition) 2022年第5期96卷 1752-1763页

作者： HOU Haihai SHAO Longyi LIANG Guodong TANG Yue ZHANG Huajie ZHANG Jiaqiang College of Mining Liaoning Technical UniversityFuxinLiaoning 123000China College of Geoscience and Surveying Engineering China University of Mining and TechnologyBeijing 100083China Oil&Gas Resource Survey Center China Geological SurveyMinistry of Land and ResourceBeijing 100029China

The coal-bearing strata in the southern Junggar Basin in northwestern China have recently attracted the attention of coal geologists. Its abundance of coal resources is of great interest as there is a potential of unlocking details about the palaeoclimatic information. Coal deposits have the capacity to record wildfire events, even those with inefficient combustions. To characterize wildfire events and palaeoclimatic history of the middle jurassic Xishanyao Formation(Aalenian and Bajocian ages), 22 coal samples from borehole cores and coal mines in the southern Junggar Basin were collected and their macerals were analyzed. The results indicated that fusinite and semi-fusinite were the dominant components of inertinite with proportions of 35.27% and 54.67%, respectively. The presence of inertinite is an indicator that wildfires occurred at the time of peat land development, and the widespread occurrence suggests large scale wildfires during the middle jurassic. This study proposes a new parameter for the evaluation of wildfire features by combining burning frequency and burning temperature. The comprehensive evaluation index(CEI) was influenced by the lacustrine basin level and ancient plant types from a sequence framework. During the middle jurassic, most wildfires were surface fires with low level and ground fire with high level. High oxygen levels were estimated in the lower, middle, and upper members of the Xishanyao Formation with corresponding to 26.78%, 24.55%, and 23.55%, respectively. The high oxygen levels would be the primary cause of repeated wildfires in the middle jurassic. These results are helpful for understanding palaeoclimatic changes in the middle jurassic.

关键词： wildfire charcoal middle jurassic comprehensive evaluation index northwestern China

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Discovery of a New middle jurassic Dinosaur Site in Sichuan,China

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Acta Geologica Sinica(English Edition) 2022年第1期96卷 52-60页

作者： HAO Baoqiao ZHANG Qiannan PENG Guangzhao YE Yong Institute of Deep Time Terrestrial Ecology Yunnan UniversityKunming 650091China Research Center of jurassic Stratigraphy and Paleontology Zigong Dinosaur MuseumZigongSichuan 643013China Key Laboratory of Stratigraphy and Paleontology Ministry of Natural ResourcesBeijing 100050China Beijing Museum of Natural History Beijing 100050China

The Sichuan Basin,also known as the‘Red Basin’,is famous for its abundance of Mesozoic dinosaur fossils,especially in the Zigong area during the jurassic era;the middle jurassic Shunosaurus and the Late jurassic Mamenchisaurus faunal assemblages are the most *** Qinglongshan dinosaur fossil site is located in Fuxing,to the northwest of Rong County,Zigong *** new site is situated within the middle jurassic Xiashaximiao Formation,and geologically is roughly equivalent to the well-known Dashanpu dinosaur fossil *** than 600 dinosaur fossils were found concentrated in the excavation area,including teeth;cervical,dorsal and caudal vertebrae;and various parts of appendicular *** fossil site is also most significant as it provides new information on non-avian dinosaur life during the poorly understood middle jurassic.

关键词： vertebrate paleontology Dinosauria Xiashaximiao Formation middle jurassic Qinglongshan Sichuan Province

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The Insect Oviposition Firstly Discovered on the middle jurassic Ginkgoales Leaf from Inner Mongolia, China

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Acta Geologica Sinica(English Edition) 2014年第1期88卷 18-28页

作者： NA Yuling SUN Chunlin LI Tao LI Yunfeng The Key Laboratory for Evolution of Past Life and Environment in Northeast Asia Ministry of Education Jilin University Research Center of Palaeontology & Stratigraphy Jilin University

Although the evidence of insect oviposition on plant organs has been reported from the late Paleozoic to the Miocene, record from the middle jurassic is still blank. This paper reports a significant evidence of insect oviposition on plant leaf from the middle jurassic for the first time. The ovipositional scar is distributed on the abaxial surface of Sphenobaiera leaf（Ginkgoales） from the middle jurassic Daohugou Formation of Inner Mongolia, China. A new ichnospecies Paleoovoidus venustus sp. nov. is described. The scar is elliptic to oval, arranged in longitudinal rows between leaf veins with almost regular distance, with its long axis paralleling to the leaf venation. This discovery adds new information to the morphology of insect endophytic oviposition probably produced by Odonata existed in a terrestrial ecosystem ~165 Ma ago. The new materials also provide important data for the study of insect reproductive biology, plant-insect interaction and coevolution, as well as understanding the paleoclimate and palaeoenvironment during that time in northeast China.

关键词： Fossil insect egg Oviposition Paleoovoidus Ginkgoales middle jurassic China

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A New Darwinopterid Pterosaur from the middle jurassic of Western Liaoning,Northeastern China and its Ecological Implications

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 507-514页

作者： Lu Junchang XU Li CHANG Huali ZHANG Xingliao Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Henan Geological Museum Zhengzhou 45006 China

A new species of Darwinopterus,*** *** described and *** on the new specimen,the diagnostic characters of Darwinopterus are amended and include：rostral dentition composed of well-spaced,spike-like teeth;the longest teeth are confined to the anterior half of the tooth row;tooth alveoli have raised margins;nasoantorbital fenestra confluent;inclined quadrate;elongate cervical vertebrae with low neural spine and reduced or absent ribs;long tail of more than 20 caudals partially enclosed by filiform extensions of the pre-and postzygapophyses;short metacarpus less than 60 per cent length of humerus,fifth toe with two elongate phalanges and curved second pedal phalanx of the fifth toe with the angle between the proximal and distal segments about 130 *** complete specimen of the new pterosaur *** *** much more osteological *** differences in tooth morphologies between Darwinopterus modularis and *** *** that they filled different ecological *** hard integument-bearing Coleoptera may have been the main food source of Darwinopterus robustodens.

关键词： Darwinopterus robustodens Tiaojinshan Formation middle jurassic western Liaoning China

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Response to paleoatmospheric CO_2 concentration of Solenites vimineus(Phillips)Harris(Ginkgophyta)from the middle jurassic of the Yaojie Basin,Gansu Province,China

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Science China Earth Sciences 2009年第12期52卷 2029-2039页

作者： YAN DeFei SUN BaiNian XIE SanPing LI XiangChuan WEN WenWen Key Laboratory of Western China’s Environmental Systems of the Ministry of Education Lanzhou UniversityLanzhou 730000China LPS Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China

Solenites vimineus (Phillips) Harris (Ginkgophyta) specimens with well-preserved cuticles were collected from five different beds in the oil shale member of the middle jurassic Yaojie Formation in the Yaojie Basin, Gansu Province, northwestern China. Gross morphology and fine structures of the fossil leaves were studied, and stomatal parameters were analyzed, according to which, the paleoatmospheric CO2 concentration can be deduced as 1512-1896 ppm that would have caused an increase in mean temperature of about 6.5-7.4℃. Carbon isotopes from the fossils indicate that the carbon isotopic discrimination and water use efficiency (WUE) of S. vimineus were raised nearly obtaining the ideal physiologic state in increased CO2 concentrations and temperature conditions, suggesting that S. vimineus records the paleoenvironmental information of the middle jurassic Yaojie Basin and can be used for environmental reconstruction.

关键词： Solenites vimineus stomatal parameters paleo-CO_(2)concentration carbon isotopes middle jurassic northwestern China

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Discovery of middle jurassic palaeontinids from Inner Mongolia, China (Homoptera: Palaeontinidae)

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Progress in Natural Science:Materials International 2007年第1期17卷 112-116页

作者： SHIH Chung Kun China College of Life Science Capital Normal University Beijing 100037

A new genus and three new species of fossil Palaeontinidae, Papilioncossus conchatus sp. nov., P. giganteus sp. nov. and P. pteroideus sp. nov., are described. All of them were collected from middle jurassic Jiulongshan Formation in Inner Mongolia, China. Based on distal part of forewing broader and longer than basal and Sc usually with branches, the new taxa are attributed to Palaeontinidae of Homoptera and compared with genus Pseudocossus. A key to species of Papilioncossus gen. nov. is provided. All type specimens are deposited in the Capital Normal University.

关键词： Palaeontinidae fossil middle jurassic new genus new species Inner Mongolia.

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