Results 61 to 70 of about 2,095 (187)

Remelting of Ordovician migmatites and granites during Variscan high-grade metamorphism (Aar Massif, Central Alps, Switzerland) [PDF]

Swiss Journal of Geosciences
The remelting of felsic gneisses, migmatites and granite during a later orogenic cycle can produce rocks of different age with comparable field appearance, microstructure, mineralogical and chemical composition.
Urs Schaltegger, Alfons Berger, Jürgen Abrecht, Alexey Ulianov, Eliana Noroña Muñoz, Daniela Rubatto, Maria Ovtcharova, Agathe Martignier, Richard Spikings, Michael Wiederkehr   +9 more
doaj   +3 more sources

Nacre in Molluscs from the Ordovician of the Midwestern United States

Geosciences, 2013
Nacre was previously thought to be primitive in the Mollusca, but no convincing Cambrian examples are known. This aragonitic microstructure with crystal tablets that grow within an organic framework is thought to be the strongest, most fracture-resistant
Steven D.J. Baumann, William P. Heimbrock, Antonio Checa, Michael J. Vendrasco   +3 more
doaj   +1 more source

FAULT SYSTEMS IN THE UPPER CRUST OF THE CENTRAL ASIAN FOLDING BELT

Известия высших учебных заведений: Геология и разведка, 2020
This article considers the disjunctive deformation of the upper crust in the Tien Shan and Altai-Sayan regions of the Central Asian folding belt. An analysis of the diagrams of fault directions constructed on the basis of information on more than 3000 ...
V. S. Burtman
doaj   +1 more source

Evolution of the Ordovician top boundary and its relationship to reservoirs' development, Ordos Basin

Petroleum Exploration and Development, 2012
The control of structural evolution on the development of different types of Ordovician reservoirs in the Ordos Basin is discussed by studying the evolution of the Ordovician top boundary in geological times, and the mechanisms of formation and evolution
Xinquan RAN, Jinhua FU, Xinshan WEI, Junfeng REN, Liuyi SUN, Hongping BAO   +5 more
doaj   +1 more source

The Magnetic Signature of Shear Zones in Marbles and Experimental Simulations

Geoscience Data Journal, Volume 13, Issue 4, October 2026.
This dataset explores how strain, microstructure, texture and magnetic susceptibility interact in natural and experimental shear zones. It includes data from low‐ and high‐temperature marble shear zones and analogue experiments simulating different deformation regimes.
Vladimír Kusbach, Zuzana Roxerová, Matěj Machek, Monika Kučeráková, Stanislav Vratislav, Anna Vávrová, Martin Chadima, Pedro F. Silva, Martin Racek   +8 more
wiley   +1 more source

Characteristics, distribution, and origin of ferruginous deposits within the Late Ordovician glaciogenic setting of Arabia. [PDF]

Sci Rep, 2023
Alqubalee A, Salisu AM, Bello AM, Al-Hussaini A, Al-Ramadan K.   +4 more
europepmc   +1 more source

WARM TO COLD WATER CARBONATE FORMATION DURING THE ORDOVICIAN AND THE JURASSIC: EXAMPLES FROM IRAN, AUSTRALIA, AND ENGLAND [PDF]

Journal of Sciences, Islamic Republic of Iran, 2003
Isotope data from bulk carbonates, micrite, marine calcite cements, non-skeletal grains and brachiopods indicate deposition of a wide spectrum of warm to cold water carbonates during the Ordovician and the Jurassic.
doaj  

Hydrocarbon fluid evolution and accumulation process in ultradeep reservoirs of the northern Fuman Oilfield, Tarim Basin

Frontiers in Earth Science
Marine deep Ordovician reservoirs are significantly controlled by strike-slip fault zones, which govern reservoir fluid evolution during various activity periods.
Rujun Wang, Yingtao Zhang, Fangfang Chen, Mengqin Li, Zhigang Wen, Zhigang Wen, Xiao Luo, Zhiwen Ding, Bing Li, Yifan Xue, Yifan Xue   +10 more
doaj   +1 more source

Reconnaissance study of watershed and cave sediment sources discharging from a karst spring, Iowa

Agrosystems, Geosciences &Environment, Volume 9, Issue 3, September 2026.
Abstract Springs discharging from karst landscapes provide sustainable flows to natural ecosystems and support productive fish hatcheries but sediment discharging from springs threatens the long‐term sustainability of hatcheries. In this study, we conducted a reconnaissance study to evaluate watershed and cave sediment sources discharging to Siewers ...
Keith E. Schilling, Joseph Honings, Thomas Doyle, Calvin Wolter, David Peate   +4 more
wiley   +1 more source

Rapid marine oxygen variability: Driver of the Late Ordovician mass extinction. [PDF]

Sci Adv, 2022
Kozik NP, Young SA, Newby SM, Liu M, Chen D, Hammarlund EU, Bond DPG, Them TR, Owens JD.   +8 more
europepmc   +1 more source