Results 41 to 50 of about 1,497,171 (212)

New data on Upper Carboniferous–Lower Permian deposits of Bol'shevik Island, Severnaya Zemlya Archipelago [PDF]

Polar Research, 2015
We present here a detailed study of the Upper Carboniferous–Lower Permian stratigraphy of Bol'shevik Island in the Severnaya Zemlya Archipelago, consisting of the analysis of sedimentary structures and lithostratigraphy, U/Pb detrital zircon dating and ...
Victoria B. Ershova, Andrei V. Prokopiev, Valery A. Nikishin, Andrey K. Khudoley, Nikolay A. Malyshev, Anatoly M. Nikishin   +5 more
doaj   +1 more source

Machaeridians from the Middle and Upper Ordovician of the Argentine Precordillera

Geological Journal, 2012
The machaeridians are marine Palaeozoic annelids, which developed a dorsal skeleton composed of calcite sclerites, achieving a world‐wide distribution from the Early Ordovician to the Middle Permian. The absence of records from this group is notable in Argentina in spite of intense studies of Palaeozoic rocks.
Ortega, Gladys del Carmen, Albanesi, Guillermo Luis, Zeballo, Fernando Javier   +2 more
openaire   +2 more sources

Morphological plasticity in the dentition of the lungfish Gnathorhiza from the Permian of Brazil: A population‐level geometric morphometric analysis

The Anatomical Record, EarlyView.
Abstract Dental plates are pivotal in the lungfish paleontological record, constituting highly mineralized structures resilient to diagenetic processes. This study provides a detailed description and quantitative shape analysis of 95 newly discovered Gnathorhiza sp. dental plates from the Middle–Late Permian Corumbataí Formation, Brazil.
Mauro B. S. Lacerda, Gustavo H. N. Petreca, Gabriel E. B. de Barros, Ana Emilia Quezado, Marcelo A. Fernandes   +4 more
wiley   +1 more source

Bioerosion traces in bones reveal an increase in ethological diversity in the insect exploitation of carcasses in the late Triassic

The Anatomical Record, EarlyView.
Abstract This study presents the first detailed description of bioerosion traces produced by insects in bones from the Santa Cruz Sequence (early Carnian, Santa Maria Supersequence, Brazil). An array of traces is reported, consisting of notches, a tube, trails of grooves attributed to the ichnotaxon Osteocallis mandibulus and ornamented depressions ...
Lucca S. Cunha, Francesco Battista, Heitor Francischini   +2 more
wiley   +1 more source

The SPICE carbon isotope excursion in Siberia: a combined study of the upper Middle Cambrian-lowermost Ordovician Kulyumbe River section, northwestern Siberian Platform [PDF]

, 2008
An integrated, high-resolution chemostratigraphic (C, O and Sr isotopes) and magnetostratigraphic study through the upper Middle Cambrian–lowermost Ordovician shallowmarine carbonates of the northwestern margin of the Siberian Platform is reported. The
Gallet, Y, Kouchinsky, A, Pavlov, V, Ziegler, K, Runnegar, B, Shields, G, Young, E, Bengtson, S, Veizer, J, Korovnikov, I   +9 more
core  

Cortical bone geometry and static gravitational loads in neosauropod dinosaurs: Implications for biomechanical constraints on terrestrial gigantism

The Anatomical Record, EarlyView.
Abstract Sauropod dinosaurs achieved unprecedented terrestrial gigantism, raising questions about the biomechanical limits of bone under extreme gravitational loads. We estimated static gravitational pressures (Pg) on appendicular cortical bone in neosauropods, including diplodocoids, brachiosaurids, and titanosaurs.
Tito Aureliano, Aline M. Ghilardi, Holly N. Woodward, Horácio W. L. Alves, Guilherme M. Sipahi   +4 more
wiley   +1 more source

Recent developments in the Upper Ordovician and lower Silurian conodont biostratigraphy in Estonia [PDF]

Estonian Journal of Earth Sciences, 2007
The current state of and the latest developments in the conodont-based biostratigraphical studies of Upper Ordovician and lower Silurian strata in Estonia are discussed.
Männik, Peep
doaj  

Dynamic geo‐hydrogeological monitoring‐driven situational awareness for real‐time floor water inrush risk prediction in deep mining

Deep Underground Science and Engineering, EarlyView.
The fused data extracted from the distributed monitoring system as the data basis, combined with dynamic geological data, are imported into a deep learning model. As the geological conditions of mining and excavation change, the risk of water inrush at the working face is retrieved in real time.
Yongjie Li, Huiyong Yin, Fangying Dong, Tao Wu, Chao Zhang   +4 more
wiley   +1 more source

An extremely brief end Ordovician mass extinction linked to abrupt onset of glaciation

Solid Earth Sciences, 2019
The end Ordovician mass extinction (EOME) was the second most severe biotic crisis in Phanerozoic, and has been widely linked to a major glaciation. However, robust geochronology of this interval is still lacking.
Ming-Xing Ling, Ren-Bin Zhan, Guang-Xu Wang, Yi Wang, Yuri Amelin, Peng Tang, Jian-Bo Liu, Jisuo Jin, Bing Huang, Rong-Chang Wu, Shuo Xue, Bin Fu, Vickie C. Bennett, Xin Wei, Xiao-Cong Luan, Seth Finnegan, David A.T. Harper, Jia-Yu Rong   +17 more
doaj   +1 more source

Discovery of high‐quality Cambrian source rocks in China's first 10 000‐m‐deep well

Deep Underground Science and Engineering, EarlyView.
Well SDTK1 penetrated the Lower Cambrian Yurtus Formation at 10 851–10 910 m in the Tarim Basin, providing the first direct drilling evidence of effective marine source rocks below 10 km. Despite overmature thermal evolution, the lower argillaceous interval retains an average total organic carbon of 4.3% and an average S1 + S2 value of 3.8 mg/g ...
Sen Zhu, Qingwen Tan, Wanyan Lan, Fangkai Liu, Guangyou Zhu   +4 more
wiley   +1 more source