Results 71 to 80 of about 5,673 (250)

MIDDLE JURASSIC NAUTILOIDEA FROM WESTERN FRANCE

Rivista Italiana di Paleontologia e Stratigrafia, 2004
The Middle Jurassic shelf margin limestones and marly limestones of Western France yield quite numerous Nautilida. This record is here described for the first time in detail, nine genera and more than forty species, whose range rarely exceeds one or two ...
PATRICK BRANGER
doaj   +1 more source

Mechanisms of Roadway Instability and Coupled Control Technology for Working Face Passing Through Fault Zones

Energy Science &Engineering, EarlyView.
This study mainly explores the instability characteristics of roadways near faults in the working face. Taking the 51104 transportation roadway of the 51104 working face in Shengxin Coal Mine as the main research object, through theoretical analysis, borehole inspection, numerical simulation and on‐site mine pressure observation, the instability ...
Shuaifeng Yin, Yitao Yan, En Wang, Xubo Zhao, Kanglei Han   +4 more
wiley   +1 more source

Control Mechanism of Pore Structure of Different Macroscopic Lithotypes on Gas Desorption Differences: A Case Study of High‐Rank Coal From the Western Ordos Basin

Energy Science &Engineering, EarlyView.
论文陈述 Paper Statement 本研究揭示了不同宏观煤岩类型的差异化控气机制:半亮煤是主要“储气核心,” 光亮煤为关键“渗流通道,” 暗淡煤则是“初期高产贡献者”。这为深层煤层气甜点优选与定制开发提供了关键理论依据。 This study reveals the differentiated gas‐controlling mechanisms of different macroscopic coal lithotypes: semibright coal acts as the primary “gas storage core,” bright coal serves as the critical “seepage channel,” and dull coal functions
Heng Li, Conghui Liu, Chen Li, Peipei Zhu, Sijie Feng, Rui Shi, Jian Shen   +6 more
wiley   +1 more source

Numerical Simulation Study on Optimization of Horizontal Sublevel Top‐Coal Caving Mining Technique for Steeply Inclined Extra‐Thick Coal Seam

Energy Science &Engineering, EarlyView.
As the sublevel height increases, the top‐coal recovery amount gradually increases, but both the top‐coal recovery rate and the thickened top‐coal recovery rate show a downward trend, and the decline in the top‐coal recovery rate is gradually increasing. The comparison indicates that the optimal sublevel height is 20 m.
Hongsheng Tu, Dingyi Hao, Wenhong Xiao, Fuhao Jiang, Shikun Xu   +4 more
wiley   +1 more source

Early and middle Bajocian (Middle Jurassic) ammonites from southern Alaska [PDF]

Professional Paper, 1984
Early and middle Bajocian (Middle Jurassic) ammonites have been found in six areas in southern Alaska over a distance of about 500 mi (800 km) from the Wrangell Mountains on the east to the Wide Bay area of the Alaska Peninsula on the west. In the Wrangell Mountains, some float obtained near the base of the Nizina Mountain Formation has furnished the ...
openaire   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

Geological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

The Jurassic of North-East Greenland: Maximum Middle Jurassic transgression in East Greenland: evidence from new ammonite finds, Bjørnedal, Traill Ø [PDF]

Geological Survey of Denmark and Greenland Bulletin, 2004
A Middle – lower Upper Jurassic sandstone-dominated succession, more than 550 m thick, with mudstone intercalations in the middle part is exposed in Bjørnedal on Traill Ø, North-East Greenland.
Alsen, Peter, Surlyk, Finn
doaj  

Decoupling glacier retreat and surface stabilization on the Snežnik Plateau (Slovenia), insights from in situ cosmogenic 36Cl exposure and depth‐profile ages

Journal of Quaternary Science, EarlyView.
ABSTRACT Glaciokarst landscapes pose distinctive challenges for cosmogenic dating because meltwater and runoff can be rapidly rerouted into ponors and conduit networks, weakening glacier–river coupling and promoting local sediment storage. We reconstruct glacier retreat and postglacial stabilization on the Snežnik Plateau (SW Slovenia) using in situ ...
Onur Altınay, Mehmet Akif Sarıkaya, Uroš Stepišnik, Manja Žebre, Cengiz Yıldırım, Attila Çiner, Klaus M. Wilcken   +6 more
wiley   +1 more source

Ostracod faunal and geochemical evidence for the impact of Hoxnian (MIS 11c) sea levels in eastern England

Journal of Quaternary Science, EarlyView.
ABSTRACT Marine isotope substage 11c (~426–366 ka) is widely regarded as the most recent Pleistocene interglacial that is broadly analogous to the Holocene. The timing and magnitude of sea‐level changes during MIS 11 have been much debated, particularly concerning whether sea levels were significantly higher than during the Holocene. Empirical evidence
Tom S. White, Jonathan A. Holmes, David J. Horne, David R. Bridgland   +3 more
wiley   +1 more source

Middle Jurassic ankylosaur tracks from Mexico

Boletín de la Sociedad Geológica Mexicana, 2018
espanolUna localidad icnofosilifera en una de las orillas del Rio Numi en las cercanias de la Ciudad de Tlaxiaco, noroeste de Oaxaca, al sur de Mexico, conserva las huellas de dinosaurios sauropodos y teropodos; esta se localiza dentro de la secuencia estratigrafica de la Formacion Zorrillo-Taberna Indiferenciadas, de edad Jurasico Medio (Bajociano ...
Rubén A. Rodríguez-de la Rosa, María Patricia Velasco-de León, Javier Arellano-Gil, Diego Enrique Lozano-Carmona   +3 more
openaire   +2 more sources