Results 81 to 90 of about 7,297 (224)
A Sequence-Stratigraphic Perspective of the Late Ordovician Mass Extinction [PDF]
, 2023 Mass extinctions throughout the history of life are a remarkable source of information on the relationship between past changes to the Earth System and global biodiversity.
Zimmt, Joshua Ben
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Geologica Acta, 2009 New SHRIMP U-Pb zircon ages are reported for igneous and sedimentary rocks of the Famatina Complex, constraining the age of the magmatism and the ensialic basins.
J.A. DAHLQUIST +7 more
doaj
Remelting of Ordovician migmatites and granites during Variscan high-grade metamorphism (Aar Massif, Central Alps, Switzerland) [PDF]
Swiss Journal of GeosciencesThe 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 +9 more
doaj +3 more sources
Sedimentology, EarlyView.ABSTRACT Filamentous, anastomosing spar‐filled networks in Phanerozoic carbonates have been interpreted as the mineralised remains of keratose (non‐spiculate) sponges, yet their recognition remains contested because fabrics of broadly similar appearance may arise from microbial, diagenetic or physical processes. This study combines direct fossil–modern
Jeong‐Hyun Lee +2 more
wiley +1 more source
Ordovician succession, Hinlopenstretet. [PDF]
, 2017 28 pages : illustrations (some color), map ; 26 cm.The Ordovician sections along the western shore of the Hinlopen Strait, Ny Friesland, Spitsbergen were discovered in the late 1960s and since then prompted numerous paleontological publications; several ...
Kröger, Björn. +3 more
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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 +3 more
doaj +1 more source
, 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 +9 more
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Geosphere and biosphere dynamics during late Ordovician climate change [PDF]
, 2008 The late Ordovician was a period of major climatic and biological change, much of which is poorly understood. Global cooling began in the Caradoc (early Katian) with the build-up of ice in southern polar regions of the palaeocontinent of Gondwana ...
Challands, Thomas J.
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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
Timing of deposition, orogenesis and glaciation within the Dalradian rocks of Scotland: constraints from U-Pb zircon ages [PDF]
, 2002 The stratigraphical and structural continuity of the Late Proterozoic Dalradian rocks of the Scottish Highlands is re-examined in the light of new U-Pb zircon ages on the tuffs belonging to the Tayvallich Volcanic Formation (601 ñ 4 Ma), and on the late ...
Paterson, BA +15 more
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