检索结果-南通市图书馆

Middle Cretaceous pCO_2 Variation in Yumen, Gansu Province and its Response to the Climate Events

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第2期92卷 801-813页

作者： LEI Xiangtong DU Zhen DU Baoxia ZHANG Mingzhen sun bainian School of Earth Sciences & Key Laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Key Laboratory of Petroleum Resources Gansu Province/Key Laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences

The palaeo-atmospheric CO2 concentration （pCOz） variation in the Yumen, Gansu Province during the middle Cretaceous has been reconstructed using the newly established plant photosynthetic gas exchange mechanistic model, and the results show that the pCO2 values are in the range of about 550 -808 ppmv. The present pCO2 values are higher than the pCO2 results （531-641 ppmv） of the previous study according to the Recent standardization of the stomatal ratio method, and much lower than the pCO2 results （882-1060 ppmv） according to the Carboniferous standardization of the stomatal ratio method. The present pCOz variation is not only within the error range of GEOCARB II and GEOCARB Ill but also is similar to the reconstructed results based on the biochemistry and carbon isotope models. Besides, the present Brachyphyllum specimens were collected from four consecutive horizons of the upper Zhonggou Formation of the Hanxia Section, and the reconstructed pCO2 exhibits the reconstructed pCO2 exhibits a decline trend during the late Aptian to early Albian. This decline variation is probably associated with the Oceanic Anoxic Events （OAElb） and the Cold snap event. With the combination of pCO2 during the Albian to Cenomanian recovered by the plant photosynthetic gas exchange mechanistic model, the pCO2 showed a prominent increase during the late Aptian to early Cenominian, which indicates a response to the greenhouse warming during the middle Cretaceous. Therefore, the mechanical model of the plant photosynthetic gas exchange shows a relatively strong accuracy in the reconstruction of thepCO2 and can reflect a strong relation between the atmospheric CO2 concentrations and climatic events.

关键词： pCO2 greenhouse climate plant photosynthetic gas exchange mechanical model OAElb,Cold snap

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

在线全文

学校读者我要写书评

暂无评论

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

New Schizolepis Fossils from the Early Cretaceous in Inner Mongolia, China and its Phylogenetic Position

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2013年第5期87卷 1250-1263页

作者： XU Xiaohui LI Ruiyun DONG Chong WANG Qiujun JIN Peihong sun bainian School of Earth Sciences&Key Laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University

Three Schizolepis species collected from the Lower Cretaceous layer of the Huolinhe Basin, Inner Mongolia, China are described. These fossils are Schizolepis longipetiolus Xu XH et sun BN sp. nov., which is a new species, Schizolepis cf. heilongjiangensis Zheng et Zhang, and Schizolepis neimengensis Deng. The new species is a well-preserved female cone, slender and cylindrical in shape. The seed-scale complexes have long petioles and are arranged on the cone axis loosely and helically. The seed scales are divided into two lobes from the base. Each lobe is semicircular or elongate ligulate in shape, widest at the middle or the lower middle part, with an obtuse or bluntly pointed apex. The inner margin is almost straight and the outer margin is strongly arched. On the surface of the lobe, there are longitudinal and somewhat radial striations from the base to the margin. The seed is borne on the adaxial surface at the base or middle of each lobe. Schizolepis was estabfished in 1847, and, although more than twenty species have been discovered and reported, its phylogenetic position is controversial because of the imperfection of fossils. Most authors have considered there to be a close evolutionary relationship between Schizolepis and extant Pinaceae. Here, we analyze characteristics and compare Schizolepis with Picea crassifolia Kom, which is morphologically most similar to Schizolepis. The results indicate that the genus probably has a distant evolutionary relationship with extant Pinaceae. A detailed statistical analysis of the global paleogeographic distribution of Schizolepis showed that all the fossils of this genus appeared in strata ranging from the Upper Triassic to the Lower Cretaceous in the North Hemisphere, being rare in the Upper Triassic and Lower Jurassic, but being very common from the Middle Jurassic to the Lower Cretaceous, and particularly abundant in the Lower Cretaceous. According to the statistical results, we speculate that the genus originated i

关键词： Schizolepis systematic evolution paleogeographic distribution Early Cretaceous cause of extinction Inner Mongolia

Anatomical variations of living and fossil Liquidambar leaves:A proxy for paleoenvironmental reconstruction

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第4期54卷 493-508页

作者： XIAO Liang sun bainian LI XiangChuan REN WenXiu JIA Hui Key Laboratory of Western China's Environmental Systems of the Ministry of Education and College of Earth and Environment Science Lanzhou University Lanzhou 730000 China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China College of Arts and Sciences Bryant University Smithfield RI 02917 U.S.A. Key Laboratory of Western China's Mineral Resources and Geological Engineering of Ministry of Education Chang'an University Xi'an 710054 China

Based on living ***,we have established that such epidermal cell properties as epidermal cell circumference(Circum.) ,undulation index(UI) ,epidermal cell area(EA) on both upper and lower epidermis and the corresponding epidermal cell density(ED) ,are suitable to differentiate between sun and shade ***,stomatal properties on the lower epidermis,including stomatal length(SL) ,stomatal pore length(PL) and the corresponding stomatal density(SD) ,are reliable parameters to identify sun/shade *** this anatomical approach was applied to 18 leaf remains of *** from the Miocene Xiannanshan Formation,Zhejiang Province(eastern China) ,and the fossil leaves were sorted into two groups,namely,sun and shade *** indicates that anatomical differences between sun and shade leaves found in living species could be used for fossil ***,the variation of UI between sun and shade morphotypes is larger on the upper epidermis as compared with the lower epidermis,showing that the UI on the upper epidermis is more sensitive to environmental *** addition,anatomical features are more variable in sun leaves than in shade leaves for both modern and fossil Liquidambar,suggesting sun leaves may be more sensitive to environmental *** leaves can then be a better indicator of paleoenvironmental ***,stomatal parameters of sun morphotype should be adopted on reconstructing paleoenvironments using Liquidambar leaf *** the other hand,the three-lobed fossil *** leaf assemblage in the Xiananshan Formation is represented by an almost similar percentage of sun and shade morphotypes(56%and 44%,respectively) ,which is attributed to the short transport before *** a result,identifying sun/shade morphotypes are very useful in reconstructing paleoenvironments based on fossil leaves of Liquidambar.

关键词： Liquidambarformosana Liquidambar miosinica leaf anatomy the Miocene Xiananshan Formation sun and shade leaves

A new gnetalean macrofossil from the Lower Cretaceous of the Laiyang Basin, eastern China

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2024年第5期46卷 678-682页

作者： Peihong Jin Mingzhen Zhang Baoxia Du Jing Zhang bainian sun Key Laboratory of Petroleum Resources Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesGansu ProvinceLanzhou 730000China Key Laboratory Western China's Mineral Resources of Gansu Province Lanzhou UniversityLanzhou 730000China

Gnetophytes are a key group of plant for understanding seed plant phylogeny,partly because of their unique and elusive morphology,such as xylem with vessels,phloem with chaperones,reticular veins,and double fertilization(Endress,1996).In particular,the ovule bears a membranous integument,the upper part of which extends beyond the seed envelope to form a micropylar ***,gnetophytes occupy a unique evolutionary position in the phylogeny of seed plants and apparently represent a transition between angiosperms and other gymnosperms(Ran et al.,2018).Modern gnetophytes consist of only three families:Ephedraceae,Gnetaceae,and Welwitschiaceae,and each family contains only one ***(Ephedra L.)are the earliest diverging group of Gnetales,with a total of 70 extant species,and usually occur in cold and arid places in Asia,Europe,northern Africa,western North America and South America(Price,1996;Yang et al.,2017b).

关键词： phylogeny occupy Cretaceous

A New Species of Cupressinocladus from the Lower Cretaceous of Guyang Basin,Inner Mongolia,China and Cluster Analysis

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2017年第4期91卷 1200-1214页

作者： JIN Peihong MAO Teng DONG Junling WANG Zixi sun Mingxuan XU Xiaohui DU Baoxia sun bainian School of Earth Sciences & Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou University School of Electrical Engineering and Computer Science Louisiana State University

Cupressinocladus Seward is a fossil genus of conifers and conifer fossils with reproductive organs are very rare. In general, it is difficult to understand the natural affinities with other conifers. In this paper, a new species, Cupressinocladus guyangensis P.H. Jin et B.N. sun sp. nov., is reported based on branches with immature female cones from the Lower Cretaceous Guyang Formation of the Guyang Basin in Inner Mongolia, northern China. The foliage shoots are decussate. Leaves are decussate, imbricate, scale-like, weakly dimorphic, and bear longitudinal glands on the abaxial view. Stomata complexes are haplocheilic, monocyclic, irregularly arranged, and spread along the leaf margin. Immature female cones are subglobose with 6-8 cone scales, and three subglobose ovules arranged in a row at the base of the cone scales. Moreover, we performed cluster analysis using a statistics and machine learning toolbox for 23 fossils and extant species based on 16 morphological characters. The result implies that the new species bears a close resemblance to the extant Cupressusfunebris Endl. and might have nearest systematic affinities to it.

关键词： Cupressinocladus Immature female cone Lower Cretaceous Cluster analysis New species

An exceptionally well-preserved herbaceous eudicot from the Early Cretaceous(late Aptian–early Albian)of Northwest China

在线全文

学校读者我要写书评

暂无评论

National Science Review 2021年第12期8卷 46-54页

作者： Baoxia Du Mingzhen Zhang bainian sun Aijing Li Jing Zhang Defei Yan Sanping Xie Jingyu Wu Key Laboratory of Mineral Resources in Western China (Gansu Province) Lanzhou University Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Key Laboratory of Petroleum and Resources Gansu Province

A fossil eudicot, Gansufructus saligna gen. et sp. nov., is reported from the Early Cretaceous(late Aptian–early Albian) of the Gansu Province, Northwest China, based on numerous well-preserved axes with attached leaves and infructescences. The leaves are alternate, short petiolate and linear-lanceolate with low rank pinnate to reticulate venation. The infructescences are loose panicles bearing fruits in different stages of maturity, each containing four partly free carpels borne in a whorled arrangement. Each carpel has three to five seeds borne along its ventral margin. The nature of the leaves and axes indicates a terrestrial,herbaceous habit. In general organization, Gansufructus is closely similar to the fruit-bearing axes of Sinocarpus decussatus from the Early Cretaceous Jehol Biota, as well as other more or less contemporaneous angiosperms from the Far East, which together provide evidence of diverse eudicot angiosperms of low stature colonizing areas close to environments of deposition.

关键词： eudicot Early Cretaceous Northwest China Jehol Biota Gansufructus paleoecology

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

Fossil Liverworts from the Lower Cretaceous Huolinhe Formation in Inner Mongolia, China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2016年第3期90卷 838-846页

作者： LI Ruiyun WANG Xuelian JIN Peihong MA Fujun YAN Defei LIN Zhicheng sun bainian School of Earth Sciences&Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou University Northwest University Museum Northwest University Key Laboratory of Economic Stratigraphy and Palaeogeography Nanjing Institute of Geology and PalaeontologyCAS School of Petroleum Engineering Chongqing University of Science & Technology

A new genus and species, Rebouliothallus huolinhensis sp. nov., and two uncertain species, Ricciopsis sp. and Hepaticites sp., are described. The fossils were collected from the Lower Cretaceous Huolinhe Formation of Huolinhe Basin, northeastern China. The new genus Rebouliothallus was established in the Aytoniaceae family of Marchantiales. Rebouliothallus huolinhensis appears to be quite similar to species of the extant genus Reboulia Raddi. The species is characterized by the relatively large ventral scales. Ventral scales are large, imbricate and arranged in two rows on the ventral surface. Rhizoids are either pegged or smooth. Ricciopsis sp. is characterized by the rosette- forming thallus. Hepaticites sp. shows some similarities to liverworts. Of the forty-nine Early Cretaceous floras of China, only two floras, one from the Huolinhe basin, Inner Mongolia and the other from the Jixi Basin, Heilongjiang Province, contain fossil liverworts. The rare fossil liverwort records in the Early Cretaceous floras of China may be the result of taphonomic bias.

关键词： Rebouliothallus Ricciopsis Hepaticites Early Cretaceous Huolinhe Formation