The Cretaceous paleo-ocean has experienced multiple phases of Oceanic Anoxic Events (OAEs), which characterized by organic carbon enrichment, geochemical indicator anomalies and fossil assemblage changes. It includes three events, namely OAE 1, OAE 2 and OAE 3. The Cretaceous paleo-ocean has experienced multiple phases of Oceanic Anoxic Events (OAEs), which characterized by organic carbon enrichment, geochemical indicator anomalies and fossil assemblage changes. It includes three events, namely OAE 1, OAE 2 and OAE 3. Previous studies of OAE 1b events have been mainly based on marine sediments in western Tethys, and very little research has been conducted on Eurasia, which limits our insight into the response of terrestrial ecosystems to OAE 1b. Recently, ZHAO Xiangdong, a graduate student supervised by Prof. ZHENG Dajin and ZHANG Haichun, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), has found the first record of OAE 1b events in the Xiagou Formation and Zhonggou Formation of the Hanxiagou Section in Jiuquan Basin, northwestern China. The results provide direct evidence to link the OAE 1b and terrestrial ecosystem in the Eurasia. The research results have been published in GSL Special Publications, an international geological journal. "In this work, we present organic carbon isotope and total organic carbon (TOC) content data analyzed from a terrestrial succession in the Xiagou and Zhonggou Formations (upper Aptian-lower Albian), in order to characterize the OAE1b in the Eurasia continental sediments," ZHAO says, "specifically, we also analyze Hg concentrations to investigate changes in the flux of volcanic materials to terrestrial environments during the OAE 1b." On the basis of zircon U-Pb age of 112.4 ± 0.3 Ma for a basalt layer from the lowermost Zhonggou Formation, the three negative δ13Corg excursions, well corresponded with the three subevents (Kilian, Paquier, and Leenhardt) of the OAE1b in the Poggio le Guaine (central Italy), Vocontian Basin (SE France) and Santa Rosa Canyon (NE Mexico) Sections, supporting the record of the terrestrial OAE 1b in the Jiuquan Basin. Five mercury enrichment intervals in Hg/TOC ratios were recognized in the Hanxiagou Section, showing a high agreement with the previous study in the Poggio le Guaine section. This consistency indicates that mercury in both sections were probably from the same source. The volcanic eruptions of the Southern Kerguelen Plateau (119.0 –109.2 Ma) provided the Hg source and probably triggered the OAE1b (~114.5–110.5 Ma). The multiple long-term spikes observed in the Hg/TOC profile could further reflect a multiple phase emplacement of the volcanism. The Hg/TOC spikes and Carbon Isotope Excursions are not strictly at the same positions in both sections, which means a potential decoupling relationship between the global shifts in δ13C and the volcanic activity (suggested by Hg/TOC). This decoupling relationship may be resulted from another unstable and unknown carbon reservoir (not directly linked to Hg emissions) activated after the volcanism. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and the National Natural Science Foundation of China. Reference: Zhao, X.D., Zheng, D.R., Wang, H., Fang, Y.N., Xue, N.H. & Zhang, H.C. (2021). Carbon cycle perturbation and mercury anomalies in terrestrial Oceanic Anoxic Event 1b from Jiuquan Basin, NW China. GSL Special Publications. http://dx.doi.org/10.1144/SP521-2021-149. Fig. 1 Section photograph showing boundary (red line) of Xiagou and Zhonggou formations in Hanxiagou section Fig. 2. Geochemical profiles at Hanxiagou section Fig. 3. Correlation of carbon isotopic records in Hanxiagou section (Jiuquan Basin, NW China), Poggio Ie Guaine section (Umbria–Marche Basin, Italy), a composite section (Vocontian Basin, France) and the Santa Rosa Canyon section (Mexico)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Intensive volcanism has been considered a major driver of environmental/climatic changes throughout Earth history, including global warming due to excessive volcanogenic CO2 emission, acidification, ozone depletion etc., which in turn have been perceived important killing mechanisms of mass extinctions. However, direct evidences of the linkage between volcanism and paleoenvironmental /paleoclimatic perturbations are still lacking. Intensive volcanism has been considered a major driver of environmental/climatic changes throughout Earth history, including global warming due to excessive volcanogenic CO2 emission, acidification, ozone depletion etc., which in turn have been perceived important killing mechanisms of mass extinctions. However, direct evidences of the linkage between volcanism and paleoenvironmental /paleoclimatic perturbations are still lacking. The Triassic-Jurassic transition (~ 201 Ma) saw one of the most catastrophic volcanic eruptions during the Phanerozoic, namely the Central Atlantic Magmatic Province (CAMP) and it has been suggested to have triggered a series of environmental/climatic perturbations which eventually caused the end-Triassic mass extinction. However, due to the lack of volcanic ash sediments outside its eruption sites, the spatial extent to which the volcanism has had impact on is not well understood. Recently, researchers from China University of Geosciences (Wuhan), Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with other institutions from USA, have reported elevated Hg concentrations and isotopes from terrestrial sediments of two sites in the Junggar Basin and the Sichuan Basin in China, which are spatially distant from the CAMP and interpreted them as direct evidences of intense volcanism in association with CAMP. This study was published online in the journal Nature Communications. Besides, these researchers also reported pronounced elemental and clay mineralogical changes at the same level as the elevated Hg concentrations and interpreted these changes as solid signs of enhanced weathering intensity of sediment sources. Resultantly, the researchers then suggested a causal link between intensified volcanisms and chemical weathering of sediments during that time. "Our work is the first to show direct linkage between intensified volcanism and immediate weathering response outside of the CAMP sites during that critical time interval in Earth history," Prof. WANG Yongdong says. With the help of previous time framework established by astronomical cycles, the researchers found out that the impact of volcanism on weathering has lasted for ~ 2 million years, which is consistent with their modelling results. Altogether, these researchers suggested that chemical weathering of rocks on land may have been an important method Mother Earth adopted to draw down excess CO2 in the atmosphere in order to maintain relatively stable climatic conditions on the Earth surface ecosystems. Also by comparing the amplitude of the enhancement of chemical weathering conditions between the two study sites which occupied a high and a low paleolatitudes respectively, those researchers also concluded that chemical weathering responded more pronouncedly in the higher latitudes than in the low latitudes at that time during the eruption of the CAMP. Reference: Jun Shen*, Runsheng Yin, Shuang Zhang, Thomas J. Algeo, David J. Bottjer, Jianxin Yu*, Guozhen Xu, Donald Penman, Yongdong Wang*, Liqin Li, Xiao Shi, Noah J. Planavsky, Qinglai Feng, Shucheng Xie, 2022. Intensified continental chemical weathering and carbon cycle perturbations linked to volcanism during the Triassic-Jurassic transition. Nature Communications, 13, 299. https://www.nature.com/articles/s41467-022-27965-x. Fig.1 Geobal paleogeography of the Late Triassic (~200 Ma). Yellow stars represent the study sites, including The Haojiagou section (~60°N, high latitude) on the North China Craton, and the Qilixia section (~30–40°N, low/middle latitude) on the South China Craton. Circles and squares represent other marine and continental sections, respectively.
Fig.2. Geological sections of the Haojiagou in Junggar Basin of Xinjiang (Upper) and the Qilixia in the Sichuan Basin (Lower), China
Fig. 3. Profifiles of the Haojiagou (Upper, HJG) and Qilixia (Lower, QLX) sections, showing the Organic carbon isotope (δ13Corg, ‰), Mercury concentrations (Hg, ppb), Ratios of mercury to total organic carbon (Hg/TOC, ppb/wt %), Chemical index of alteration (CIA) and clay minerals. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Angiosperms may be distinguished from their gymnosperm peers bytheir flowers,and thus a flower is a good proxy of fossil angiosperms. However, flowers and their parts are usually too frail to be preserved in the fossil record. This makes the origin of angiosperms and their flowers the foci of controversy in botany. Angiosperms may be distinguished from their gymnosperm peers by their flowers, and thus a flower is a good proxy of fossil angiosperms. However, flowers and their parts are usually too frail to be preserved in the fossil record. This makes the origin of angiosperms and their flowers the foci of controversy in botany. Eliminating such botanical controversies can only be achieved by studying related plant fossils. Recently, Prof. WANG Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with scientists from South China Agricultural University, document a fossil flower bud, Florigerminis jurassica gen. et sp. nov., from the Jurassic of Inner Mongolia, China. This is the earliest fossil record of flower buds in the world so far. Their findings were published by The Geological Society of London. WANG Xin says, "this fossil includes not only a leafy branch but also physically connected fruit and flower bud." The developmentally interpolated existence of a blooming flower between the flower bud and mature fruit in Florigerminis suggests that angiosperm flowers were present in the Jurassic, in agreement with recent botanical progress. Previous plant fossils were often preserved fragmentarily, leading paleobotanists to consider them as belonging to different plants. This Florigerminis jurassica underscores the presence of angiosperms in the Jurassic and demands a rethinking of angiosperm evolution. This research was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Da-Fang Cui, Yemao Hou, Pengfei Yin, Xin Wang, 2022. A Jurassic flower bud from China. Geological Society, London, Special Publications, 521, https://doi.org/10.1144/SP521-2021-122.
Florigerminis jurassica gen. et sp. nov and its details
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Alienopteridae were originally proposed as a new insect order (Alienoptera) in 2016, and this family was considered as one of the most peculiar insects in Burmese amber. Alienopteridae were originally proposed as a new insect order (Alienoptera) in 2016, and this family was considered as one of the most peculiar insects in Burmese amber. Firstly, Alienopteridae were only discovered from mid-Cretaceous Burmese amber, but later few specimens were also reported from the Lower Cretaceous Crato Formation of Brazil and the middle Eocene Green River Formation of the USA. However, the life history, systematic position, and taxonomic status of Alienopteridae (Alienoptera) have been much disputed since the group was established. Recently, LUO Cihang, a postgraduate student, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with other scientists from NIGPAS, discovered many new specimens of Alienopteridae from the museum and/or Institute of China, Germany, USA and Slovakia. This study was published in Earth-Science Reviews on Dec. 30, 2021. The team used an array of different methods, i.e., optical microscopy, confocal laser scanning microscopy (CLSM), x-ray microcomputed tomography, geometric morphometric analysis and phylogenetic analysis to evaluate the morphology, life habits and evolutionary history of Alienopteridae. "We discovered that one alienopterid nymph is laden with gymnosperm pollen grains," WANG Bo says. Therefore, by providing the first possible direct evidence of gymnosperm pollination by a fossil dictyopteran, researchers may confirm a previously unknown gymnosperm-insect association. This is the only known fossil pollination example from the Polyneoptera, one of the major lineages of winged insects and indicated that some Mesozoic dictyopterans may have been important pollinators of gymnosperm. The order Aethiocarenodea was erected using an isolated specimen from mid-Cretaceous Kachin amber and was considered as one of the most enigmatic insects in Burmese amber. This study is based on morphological observations and summaries of a large number of specimens, confirmed that Aethiocarenodea is actually a specialized type of alienopterid nymphs, and finally revised the systematic position of Aethiocarenodea. The researchers also carried out a phylogenetic analysis based on a matrix with 56 characters and 39 terminals, which evaluated the phylogenetic placement and evolution history of Alienopteridae. There have robust evidences that the Alienopteridae is a specialized taxon of Dictyoptera, sister to Umenocoleidae, and Alienopteridae alone should not be ranked as a separate order. Hence, the two families should be combined as clade Alienoptera and placed as sister to Mantodea. They probably arose before the J/K boundary and their common ancestor may have occurred in the Late Jurassic. "We also reported an alienopterid nymph fell prey to a lacewing larva." WANG says, "these discoveries provide direct evidence for us to reconstruct the Cretaceous terrestrial ecosystem and further confirm that insects already evolved complex behaviors during the Cretaceous." This research was supported by the Chinese Academy of Sciences, Ministry of Science and Technology of China and National Natural Science Foundation of China. Reference: Luo Cihang, Beutel R.G., Engel M.S., Liang Kun, Li Liqin, Li Jiahao, Xu Chunpeng, Vr？ansky P., Jarzembowski E.A., Wang Bo, 2021. Life history and evolution of the enigmatic Cretaceous–Eocene Alienopteridae: A critical review. Earth-Science Reviews. https://doi.org/10.1016/j.earscirev.2021.103914.
alienopterid nymphs and gymnospermous pollen grains Monosulcites
Phylogeny of Alienopteridae (Image by NIGPAS)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Myrmecomorphy is a phenomenon in which some animals mimic ants morphologically and behaviorally, and belongs to a special kind of anthropomorphic behavior, which is very widely distributed in nature. Myrmecomorphy is a phenomenon in which some animals mimic ants morphologically and behaviorally, and belongs to a special kind of anthropomorphic behavior, which is very widely distributed in nature. Recently, LUO Cihang, a postgraduate student, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), collaborated with other scientists from NIGPAS, discovered a new type of alienopterid nymphs from mid-Cretaceous Burmese amber. The discovery indicated that the earliest ant mimicry has already existed in mid-Cretaceous, thereby extending its geological range by approximately 50 million years. This study was published in Earth-Science Reviews on Dec. 30, 2021. More than 2000 living species of insects and spiders, representing 11 different arthropod orders, has evolved at least 30 times among arthropods. However, the fossil record of myrmecomorphy is extremely sparse and researchers know little about its origin and evolution. By using quantitative geometric morphometric analysis, researchers discovered that the body shape of these alienopterid nymphs is very close to sphecomyrmine ant (a kind of extinct ants). Moreover, the shape of the antennae and legs of these alienopterid nymphs and ants are close and the ratios of the antennae and legs to the body length are approximately the same as in some sphecomyrmine ants. "We discovered a new type of alienopterid nymphs and provided new evidence for the early evolution of ant mimicry." WANG says, "we also concluded that these nymphs adults were likely wasp mimics, therefore, we provided the first fossil record of transformational mimicry." In addition, the main progress and significances of this study also confirm wasp mimicry present in Alienopteridae adults and to report the first fossil record of transformational mimicry. Researchers confirmed that thoraco-abdominal waist-like constrictions of some alienopterid adults (adults of those ant mimics) resemble Hymenoptera. Additionally, the strongly shortened forewings of some alienopterid adults closely resemble the tegulae of Hymenoptera and the hind wing structurally similar to hymenopteran wings. Moreover, the body shape and size of some alienopterid adults are similar to some large aculeate Hymenoptera from the same deposit, especially ampulicid wasps. Interestingly, the nymphs and adults of the mid-Cretaceous alienopterid imitate entirely different hymenopteran models, and therefore probably provide the first fossil record of transformational mimicry (mimicking different organisms during their postembryonic development). This research was supported by the Chinese Academy of Sciences, Ministry of Science and Technology of China and National Natural Science Foundation of China. WU Suping from NIGPAS provided technical support for Micro-CT. We also thank Mr. HUANG Yiren and Mr. XIA Fangyuan for providing part of specimens. Reference: Luo Cihang, Beutel R.G., Engel M.S., Liang Kun, Li Liqin, Li Jiahao, Xu Chunpeng, Vr？ansky P., Jarzembowski E.A., Wang Bo, 2021. Life history and evolution of the enigmatic Cretaceous–Eocene Alienopteridae: A critical review. Earth-Science Reviews. https://doi.org/10.1016/j.earscirev.2021.103914 Fig. 1 Representative taxa of Alienopteridae and Umenocoleidae. Fig. 2 Reconstruction drawings of Alienopteridae (Image by LI Jiahao). Fig. 3 Alienopterid nymphs and ants, ants marked with M (Image by NIGPAS). Fig. 4 Ecological reconstruction of Alienopteridae (Image by YANG Dinghua). A: Ecological reconstruction of alienopterid nymphs; the brown insect at left with two cerci are alienopterid nymphs, the other three brown insects are ants. B: Ecological reconstruction of alienopterid adults.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
During the Late Permian to Early Triassic, benthic marine redox conditions in the Shangsi area varied on both short-term and long-term time scales. This study has scientific implications for revealing the spatial and temporal distribution of anoxic events, and the importance of oceanic anoxia in the end-Permian mass extinction (EPME). During the Late Permian to Early Triassic, benthic marine redox conditions in the Shangsi area varied on both short-term and long-term time scales. This study has scientific implications for revealing the spatial and temporal distribution of anoxic events, and the importance of oceanic anoxia in the end-Permian mass extinction (EPME). About 252 million years ago, more than 81 percent of animal life in the oceans and 89 percent of animal life on land went extinct. Extensive volcanism (the Siberian large igneous province magmatism and felsic volcanism in South China) is the most probable trigger of this life crisis. Oceanic/marine anoxia triggered by volcanisms is the most plausible killing mechanism for the EPME in the marine realm. Although a wealth of studies had supported the latest Permian-Griesbachian extreme anoxia, there is some opposite evidence indicating the occurrence of oxic benthic marine conditions during the Permian-Triassic interval. In addition, it has been reported that the deterioration of the marine environment was probably before the EPME. However, compared to a vast number of studies on the Permian-Triassic interval, only a few studies focusing on the paleo-oxygen levels during the Late Permian have been conducted. Therefore, further work needs to be carried out on the benthic marine redox conditions before and during the EPME. Recently, Dr. ZHENG Quanfeng, Prof. ZHANG Hua, WANG Yue, and CAO Changqun from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NGIPAS), collaborating with researchers from China University of Mining and Technology and Nanjing University, made high-resolution sedimentological and ichnological studies to reveal benthic marine redox conditions and driving mechanisms from Late Permian to the earliest Triassic at Shangsi, South China. This study was published in Earth-Science Reviews on Dec. 20. "We found that high-frequency (centimeter- to decimeter-scale) and secular (meter- to tens of meters-scale) benthic oxygen-level variations were developed at Shangsi", Dr. ZHENG says. The high-frequency variations were mostly local signals generated by transient episodic mixing and ventilation by storms and turbidity currents. While the secular variations were regional or global signals caused by regional factors and global climate changes. Anoxic/euxinic benthic marine conditions prevailed throughout the middle Wuchiapingian to the early Changhsingian at Shangsi, which persisted for 3.9 Myr (256.974–253.073 Ma). This long-term Wuchiapingian anoxia event can be correlated both regionally and globally, and was caused by paleogeographic restrictions, relative high sea levels, high marine productivities, and possible global climate changes. "In addition, we found a long-term global oxygenation event occurred during the Changhsingian, which initiated at ~253.513 Ma, followed by a major oxygenation pulse at 253.073 Ma, and further intensified at 252.739 Ma at Shangsi." This Changhsingian global oxygenation event was probably triggered by an early Changhsingian global cooling event, during which the average surface ocean temperature declined ~6 ℃, and the cold climate persisted during most of the Changhsingian. This research was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Zheng, Q.F.*, Zhang, H., Yuan, D.X., Wang, Y., Wang, W.Q., Cao, C.Q., Shen, S.Z., 2022. High-resolution sedimentology, ichnology, and benthic marine redox conditions from Late Permian to the earliest Triassic at Shangsi, South China: Local, regional, and global signals and driving mechanisms. Earth-Science Reviews, 225: https://doi.org/10.1016/j.earscirev.2021.103898. Table 1 Summary of characteristics used to define redox conditions during deposition Conditions MBD (mm) ii Sedimentary fabric Oxygen (ml/l) Euxinic/anoxic 0 1 Well laminated; no sighs of biogenic structures. 0 (H2S) suboxic 0-5 2-4 Well to faintly discontinuously laminated; partly bioturbated. 0-0.15 Lower dysoxic 0-5 5-6 Completely bioturbated or homogenized. 0.15-0.5 Upper dysoxic/oxic 5-10 5-6 Completely bioturbated or homogenized. ≥0.5 Oxic ≥10 5-6 Completely bioturbated or homogenized. ≥2.0
Fig. 1. Lithofacies, microfacies, and storm-induced structures (A, C-E) from the top Wuchiaping Formation (A and B) and the basal Talung Formation (C-G). (Image by NIGPAS) Fig. 2. Late Permian to the earliest Triassic stratigraphic distribution of conodont zones (CZ), ichnocoenoses (Ichnoc.), sedimentological log, U–Pb ages, ichnofabirc index (ii), maximum burrow diameter (MBD), redox interval (RI), redox-condition column (RC), secular ichnofabric index (s-ii), secular maximum burrow diameter (s-MBD), secular redox-condition column (sRC), astronomical ages (AA), eccentricity cycles (E) proxied by anhysteretic remanent magnetization (ARM), and relative sea level (RSL) at the Shangsi section. The U–Pb ages are from Shen et al. (2011); the ARM data is from Wu et al. (2013). (Image by NIGPAS) Fig. 3. Driving factors for the evolution of benthic-marine redox conditions at Shangsi from the Lopingian to the earliest Triassic. (Image by NIGPAS) Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The Lantian biota, discovered from the Ediacaran basinal-facies deposition of the Lantian Formation near Lantian Town of the Anhui Province, South China, yields an assemblage representing one of the oldest known complex macrofossils. These fossils are preserved on the bedding surface of black shales in the middle part of the Lantian Formation, and their age was estimated at approximately 600 Ma. The Lantian biota, discovered from the Ediacaran basinal-facies deposition of the Lantian Formation near Lantian Town of the Anhui Province, South China, yields an assemblage representing one of the oldest known complex macrofossils. These fossils are preserved on the bedding surface of black shales in the middle part of the Lantian Formation, and their age was estimated at approximately 600 Ma. The Chuaria fossils usually with spheroidal or disk-like shapes, are the most common macrofossils in the Lantian biota. Although great majority of the Lantian Chuaria fossils are preserved as carbonaceous compressions, Chuaria has been reported to be commonly preserved as pyritization enveloped by aluminosilicate minerals in the upper Member II of the Lantian Formation. The outer minerals that envelope the pyrite layer have been assigned to quartz or aluminosilicate clay minerals. However, their exact mineral compositions as well as whether these minerals have contributed to the exceptional preservation of Ediacaran Lantian Chuaria remain unclear. Dr. WANG Wei and her research group from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) employed light microscopy, field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), and Raman spectroscopy techniques to revisit the preservation of pyritized Chuaria from the Lantian biota. "Our taphonomic experiments show Chuaria fossil pyritization occurs at early fossilization process and has contributed to the soft-tissue preservation." Wang says. "The pyritization process is probably divided into at least two stages, which are characterized by distinct pyrite crystal morphologies." The pyritized Chuaria fossils are enveloped by platy minerals that are a complex mixture of quartz and magnesium-rich aluminosilicates. Integrated mineral and structural pattern analyses show that these quartz and clay minerals are both secondary overgrowth on Chuaria internal mold, which probably formed as a diagenetic product concurrent with carbonate dissolution in the Lantian black shales. Their formation is probably regulated by local micro-environment near the Chuaria bodies. These enveloped minerals may facilitate preservation and identification of Chuaria fossils, but they are probably not involved in the initial fossilization process as the early diagenetic pyritization has done. This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, and the Science and Technology Research Project for the Research Institute of Petroleum Exploration and Development, CNPC. Reference: Wang Wei*, Guan Chengguo, Zhao Xianye, Fang Yan, Zhou Chuanming, Yuan Xunlai (2022) Taphonomic study of Chuaria fossils from the Ediacaran Lantian biota of South China. Precambrian Research, 369: 106529. https://doi.org/10.1016/j.precamres.2021.106529. Fig. 1 Images of the Chuaria fossils
Fig. 2 Elemental mapping and Raman spectroscopic investigations on platy minerals Fig. 3 A simplified cartoon showing Chuaria fossilization process
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Devonian witnessed the first forest on the Earth and the earliest coal formed by land plants. The Middle to Upper Devonian of West Junggar, northern Xinjiang, China yields abundant plant fossils, and finds hydrocarbon source rocks and ancient petroleum reservoirs (APR). The petroleum reservoirs in geological history were destroyed by tectonic movements to form APR. The important mark of APR is solid bitumen. Devonian witnessed the first forest on the Earth and the earliest coal formed by land plants. The Middle to Upper Devonian of West Junggar, northern Xinjiang, China yields abundant plant fossils, and finds hydrocarbon source rocks and ancient petroleum reservoirs (APR). The petroleum reservoirs in geological history were destroyed by tectonic movements to form APR. The important mark of APR is solid bitumen. Although, the age, formation and destruction of APR have been studied before, no detailed study has been conducted on the plant fossils in APR, and the stratigraphical sequence of APR in the field is different from previous studies. Therefore, it is necessary to conduct in depth study on age, stratigraphical sequence and plant fossils of APR of North Xinjiang. Recently, the Devonian Investigation Group (DIG) of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe and Prof. WANG Yi, conducted study on age, stratigraphical sequence and plant fossils of APR of North Xinjiang. The related research results were published in Journal of Stratigraphy and the international journal Plants. Based on lithostratigraphical and palaeobotanical study to the Devonian APR, the study demonstrates that the APR belongs to the Upper Member of the Hujiersite Formation with the age of late Middle Devonian (Givetian). The core layer of APR is 2 m thick, and the lithology is dominated by sandstone and mudstone. The research also studied the genus of Barsassia in APR. Since the establishment of Barsassia in 1933, there has been a lack of systematic study for a long time, resulting in unclear and confusing generic and specific diagnoses. Here, we systematically study the Devonian lycopsid Barsassia, based on the new materials in APR. Barsassia ornata is determined as the type species of the genus, and a neotype is designated for that name. Barsassia ornata is a herbaceous lycopsid consisting of easily recognized and characteristic step-like stem and tight, pseudowhorls, and imbricate fan- or rectangular-shaped leaves, and can be used in dating and correlating the Middle Devonian terrestrial strata in Siberia, Kazakhstan and Xinjiang. References: 1. Liu, B. C; Zong, R. W; Wang, Y.; Xu, H. H*. 2021. On the age of Devonian ancient petroleum reservoir in West Junggar, northern Xinjiang, China. Journal of Stratigraphy, 45(2): 196-203. https://doi.org/10.19839/j.cnki.dcxzz.2021.0018. 2. Liu, B. C; Wang, K.; Zong, R. W; Wang, Y.; Xu, H. H*. 2021. Morphology and Nomenclature of Barsassia (Lycopsida) from the Middle Devonian of West Junggar, Xinjiang, China. Plants, 10, 2631. https://doi.org/10.3390/plants10122631.
Fig. 1：The stratigraphical sequence, outcrop and plant fossils in APR.
Fig. 2: Barsassia ornata from APR, with easily recognized and characteristic step-like stem and rectangular-shaped leaves
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Systematic study of morphologies, textures and depositional structures in mass-transport deposits (MTDs), as well as associated sedimentary lithofacies, can also help to reveal aspects of tectonic evolution and sedimentary history of basins. Subaqueous mass-transport processes, including gravity-induced slides, slumps and debris flows, are one of the mechanisms for transport of sediment into the deep sea. They are of great significance because they shape the sea floor, record climatic and tectonic signals, represent potential catastrophic hazards for human activities and serve as hydrocarbon reservoirs. Systematic study of morphologies, textures and depositional structures in mass-transport deposits (MTDs), as well as associated sedimentary lithofacies, can also help to reveal aspects of tectonic evolution and sedimentary history of basins. However, internal structures and depositional processes of carbonate MTDs are relatively poorly understood relative to siliciclastic facies due to their comparative paucity in the rock record. Moreover, it is also challenging to decipher the evolution and internal features of MTDs using remotely-sensed data and drill cores of modern deposits. Accordingly, outcrop-scale study on carbonate MTDs is one important work of sedimentologists. During the last few years, Dr. LI Wenjie and Prof. CHEN Jitao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and American cooperators worked in the Wuhai area, Inner Mongolia for several times. Multi-bedded carbonate MTDs from mid and late Darriwilian to early Sandbian are studied from the aspects of sedimentology and stratigraphy. The study is published in the international academic journal Sedimentology. Researchers measured and described the Kelimoli and Wulalike formations of several sections at centimetre scale. The MTDs layers were described in detail. Hundreds of proxies of paleoslope orientation indicators have been measured. Line drawings were made in the field and laboratory to illustrate the soft-sediment deformation structures (SSDS). According to the data and field observation, they concluded the deformational succession of carbonate slump structures, and several unique sedimentary models of carbonate mass flow. Tectonic events related to passive to foreland basin transitions, and associated platform foundering and steepening of the slope were proposed to be the trigger mechanism of the deposition of these MTDs. Their findings improved the understanding of transport mechanisms of carbonate MTDs and provided a template for predicting deformational trends of other ancient carbonate slope mass movements. Their stratigraphic and facies model may be applicable to the tectonic history of sedimentary basin analysis and unconventional hydrocarbon resource (such as shale gas) exploration of the western margin of North China. This research was supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences and National Science Foundation of U.S. Reference: Li, W. J., Chen, J. T.*, Hakim, A. J., Myrow, P. M., 2021. Middle Ordovician mass-transport deposits from western Inner Mongolia, China: Mechanisms and implications for basin evolution. Sedimentology. https://doi.org/10.1111/sed.12949.
Fig. 1 Imbricated beds and folds of the Kelimoli Formation at the Xilaifeng section Fig. 2 Breccia-filled channels of the Wulalike Formation at the Yixiantian section Fig. 3 Facies model of coarse-grained calciclastic submarine channels formed in steep siliciclastic slope settings. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The existing researches are very limited and lack systematic studies, mainly being short material descriptions and reports. Megaspore plays an important role in the study of paleovegetation and paleocatlimatic reconstruction and stratigraphy due to its properties of preserving in situ due and clear affinity to the mother plants. However, fossil megaspores have not been fully studied due to their low productivity, which is even later started and poorer developed in China has been compared with international studies. The existing researches are very limited and lack systematic studies, mainly being short material descriptions and reports. The Tarim Basin is one of the most important petroliferous basins in China. The Mesozoic strata are important hydrocarbon source rocks of the basin. A researcher group headed by Professor LI Jianguo from Nanjing Institute of Geology and Palaeotology, Chinese Academy of Sciences (NIGPAS), has set out a work on the megaspores of the Mesozoic in the basin during the last decade. They studied several hundreds of samples collected from 34 outcrop or underground drilling well sections in the Tarim Basin. A total of 108 species of 27 genera have been identified, redescribed and illustrated. Eight palynological assemblage zones spanning the Early Triassic to Early Cretaceous are recognized based on the distribution of representative taxa and compositional changes in the megaspore assemblages. Stratigraphic and palaeoenvironmental values of selected genera and species are also discussed. This work has currently been officially published by Science Press China as "Mesozoic Megaspores and Palynomorphs from Tarim Basin, Northwest China" (Palaeontologica Sinica, Volume 202). This is the first Chinese and English language controlled research monograph on fossil macrospores in China. It will strongly promote the study of Mesozoic fossil megaspores, the stratigraphic division and correlation, and petroleum exploration in the Tarim Basin. Cover of "Mesozoic Megaspores and Palynomorphs from Tarim Basin, Northwest China" Fossil plates on the inside of this monograph
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
