An overview of types and characterization of hot fluids associated with reservoir formation in petroliferous basins by Wenxuan Hu, Xiaolin Wang, Dongya Zhu, Donghua You, Haiguang Wu

“…It usually has higher temperature than the surrounding rocks and is characterized by hydrothermal mineral assemblages (e.g. fluorite, hydrothermal dolomite, and barite), positive Eu anomaly, low δ 18 O value, and high 87 Sr/ 86 Sr ratio. Cambrian and Ordovician carbonate reservoirs in the central Tarim Basin, northwestern China serve as typical examples. …”
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The oldest known digestive system consisting of both paired digestive glands and a crop from exceptionally preserved trilobites of the Guanshan Biota (Early Cambrian, China). by Melanie J Hopkins, Feiyang Chen, Shixue Hu, Zhifei Zhang

“…This combination of digestive structures has also never been observed in trilobites this old, and is rare in general, with prior evidence of it from one juvenile trilobite specimen from the late Cambrian Orsten fauna of Sweden and possibly one adult trilobite specimen from the Early Ordovician Fezouata Lagerstätte. The variation in the fidelity of preservation of digestive structures within and across different Lagerstätten may be due to variation in the type, quality, and point of digestion of food among specimens in addition to differences in mode of preservation. …”
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River capture and divide migration of the Zhuozishan area in the northwestern margin of the Ordos Block by LIN Lingling, LI Xuemei, ZHANG Huiping, MA Zifa

“…When the Cambrian and Ordovician limestones with stronger erosion resistance lie in the west wing of the Zhuozishan anticline, the other weak sedimentary clastic rocks located in its lower part, the river in the west wing would be through the core of the anticline, laterally capturing the rivers on the east of the anticline.…”
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Petrology, geochemistry and tectonic setting of alkaline mafic rocks in the Jalal Abad area in the NW of Zarand (Kerman Province): Evidence for Paleo-Tethys rifting in the Centr... by Yusef Vesali, Darush Esmaeili, Fatemeh Sepidbar, Maryam Sheibi, Shojaaldin Niroomand

“…Magmas of these OIB-type and alkaline rock associations formed from partial melting of garnet- lherzolite facieses in the plume source, during the rift-drift and seafloor spreading evolution of the Proto-Tethys oceanic lithosphere during the Ordovician through Silurian periods.…”
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The succession of Hirnantian events based on data from Baltica: brachiopods, chitinozoans, conodonts, and carbon isotopes by Kaljo, Dimitri, Hints, Linda, Männik, Peep, Nõlvak, Jaak

“…The Hirnantian (late Ordovician) environment was complex and dynamic. Understanding the correct order of events and their precise correlation with a time scale are extremely important for the development of different kinds of environmental interpretations. …”
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Risk assessment of fault water inrush during deep mining by Zhaodan Cao, Qixiong Gu, Zhen Huang, Jiaju Fu

“…However, as mining depth increases, lower coal seam mining in Yanzhou is threatened by water inrush in the Benxi Formation limestone and Ordovician limestone. The existing prediction models for the water burst at the bottom of the coal seam are less accurate than expected owing to various controlling factors and their intrinsic links. …”
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Characteristics and Accumulation Model of Silurian Tight Sandstone Gas Reservoir: A Case Study in the Shajingzi Belt, Northwest Tarim Basin, China by Yuanyin Zhang, Junfeng Zhang, Yongjin Gao, Yalei Liu, Miaoqing Miao, Qingyao Li, Zhichao Sun

“…It is found that 1) the Silurian reservoirs in the Shajingzi Belt mainly bear gas and could be defined as the typical tight sandstone reservoir with ultralow porosity generally less than 10% and low-permeability distributed between 0.1 and 10 mD, respectively; 2) petroleum substantially comes from the Cambrian–Ordovician source rocks, especially in the Awati Sag, possessing the dominant contribution from the shales in Cambrian Yuertusi Formation; 3) synthetically, three major hydrocarbon accumulation periods can be determined in the Shajingzi Belt, namely, the Late Caledonian, the Late Hercynian–Early Indosinian, and the middle Himalayan, respectively; 4) the evolution of Shajingzi Fault system apparently dominated the formation of various Silurian structural–lithologic traps in the monoclinic structure background and efficiently connected the deep source rocks in the Awati Sag, especially during Himalayan period when the current tight sandstone gas reservoirs were formed. …”
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Progress and direction of exploration and development of normally-pressured shale gas from the periphery of Sichuan Basin by Tonglou GUO, Shu JIANG, Peixian ZHANG, Ping ZENG

“…The normally-pressured shale gas reservoirs from the periphery of Sichuan Basin are then characterized using the E & P cases of the Upper Ordovician Wufeng to Lower Silurian Longmaxi formations in the Wulong, Pengshui and Daozhen areas. …”
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The Russian-Kazakh Altai orogen: An overview and main debatable issues by Inna Safonova

“…The evolution of this orogen proceeded in five major stages: (i) late Neoproterozoic–early Paleozoic subduction-accretion in the Paleo-Asian Ocean; (ii) Ordovician–Silurian passive margin; (iii) Devonian–Carboniferous active margin and collision of AMT with the Siberian continent; (iv) late Paleozoic closure of the PAO and coeval collisional magmatism; (v) Mesozoic post-collisional deformation and anarogenic magmatism, which created the modern structural collage of the Russian-Kazakh Altai orogen. …”
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On Paleozoic platycerate gastropods by Alexander Nützel, Jan Ove Ebbestad, Barbara Seuss, Axel Munnecke, Royal H. Mapes, Alex G. Cook

“…The platycerate gastropods Orthonychia yutaroi Ebbestad, sp. nov. (Ordovician, Boda Limestone, Sweden), O. enorme (Silurian, Sweden, Gotland), O. parva (Pennsylvanian, Finis Shale Member, USA), and Orthonychia sp. …”
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The ancient evolutionary origins of Scleractinia revealed by azooxanthellate corals by Stolarski Jarosław, Kitahara Marcelo V, Miller David J, Cairns Stephen D, Mazur Maciej, Meibom Anders

“…</p> <p>Conclusions</p> <p>The early divergence and distinctive morphologies of the extant gardineriid and micrabaciid corals suggest a link with Ordovician "scleractiniamorph" fossils that were previously assumed to represent extinct anthozoan skeletonized lineages. …”
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Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae by Xuejian Zhu, Rudy Lerosey-Aubril, Javier Ortega-Hernández

“…The family Hurdiidae includes the oldest (basal Cambrian Epoch 2) and youngest (Early Ordovician, possibly Early Devonian) representatives of the Radiodonta and as such, has the longest stratigraphical range of the group. …”
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The Early Devonian (Emsian) acrotretid microbrachiopod Opsiconidion minor Popov, 1981, from the Alaska/Yukon Territory border and Novaya Zemlya by Lars E. Holmer, Robert B. Blodgett, Yue Liang, Zhifei Zhang

“…Opsiconidion Ludvigsen is a stratigraphically extremely long-ranging and cosmopolitan acrotretid, which exhibits a remarkable conservatism; the morphology of the ventral valve remains essentially unchanged from the earliest Ordovician (Darriwilian) records to the Devonian.…”
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Gill function in an early arthropod and the widespread adoption of the countercurrent exchange mechanism by Jin-Bo Hou, Nigel C. Hughes, Melanie J. Hopkins, Degan Shu

“…Here we propose that the countercurrent gaseous exchange, a highly efficient respiratory mechanism, was effective in the gills of the Late Ordovician trilobite Triarthrus eatoni. In order to test this, we use computational fluid dynamics to simulate water flow around its gills and show that water velocity decreased distinctly in front of and between the swollen ends, which first encountered the oxygen-charged water, and slowed continuously at the mid-central region, forming a buffer zone with a slight increase of the water volume. …”
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MASS EXTINCTIONS AND CLADE EXTINCTIONS IN THE HISTORY OF BRACHIOPODS: BRIEF REVIEW AND A POST-PALEOZOIC CASE STUDY by ATTILA VÖRÖS, ÁDÁM T. KOCSIS, JÓZSEF PÁLFY

“…At a higher taxonomic level, a review of temporal ranges of rhynchonelliform orders reveals episodes of synchronous termination of multiple orders, here termed clade extinctions. The end-Ordovician, Late Devonian and end-Permian events are registered as both mass extinctions and clade extinctions. …”
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Hentei-Dauria fold system of the Mongolia-Okhotsk belt: magmatism, sedimentogenesis, and geodynamics by I. V. Gordienko, O. R. Minina, L. I. Vetluzhskikh, A. Ya. Medvedev, D. Odgerel

“…This region developed in three stages: (1) Late Caledonian (Ordovician – Early Silurian), (2) Early Hercynian (Late Silurian – Devonian), and (3) Late Hercynian (Carboniferous–Permian). …”
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Evolution of overmature marine shale porosity and implication to the free gas volume by Feiyu WANG, Jing GUAN, Weiping FENG, Linyan BAO

“…The porosities of the Lower Cambrian shale and Upper Ordovician-Lower Silurian marine shale from the Sichuan Basin were analyzed using He-Hg porosimetry and field-emission scanning electron microscopy, to discuss the relationship of porosity to the organic matter maturity, total organic carbon (TOC) and free gas volume. …”
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Constraints on brittle field exhumation of the Everest-Makalu section of the Greater Himalayan Sequence: Implications for models of crustal flow by Streule, M, Carter, A, Searle, M, Cottle, J

“…Apatite FT ages in the Everest Series and summit Ordovician limestones are much older, up to 30.5±5.1Ma. …”

Oxygen isotope variability in conodonts: implications for reconstructing Palaeozoic palaeoclimates and palaeoceanography by Wheeley, JR, Smith, M, Boomer, I

“…Here, ion microprobe analyses of Ordovician and Silurian conodonts establishes that: intra-element crown tissue δ 18O typically varies by &lt;1%o (53% of conodonts analysed), is normally &lt;2%o (92% of analyses), and rarely varies by 2-4%o; δ 18O can vary across elements, suggesting a microstructural and/or diagenetic control; δ 18O can vary between species representatives by c. 3%o; δ 18O of pelagic and nektobenthic taxa can be offset by 2-3%o; elements processed with formic acid have highly variable δ 18O; and thermal alteration does affect δ 18O. …”

Tonian deltaic and storm-influenced marine sedimentation on the edge of Laurentia: the Veteranen Group of northeastern Spitsbergen, Svalbard by Gibson, TM, Millikin, AEG, Anderson, RP, Myrow, PM, Rooney, AD, Strauss, JV

“…The Hecla Hoek succession of northeastern Svalbard, Norway, is an ~7 km thick Tonian– Ordovician sedimentary succession that overlies Stenian–Tonian felsic igneous and metasedimentary rocks. …”