Results 1 to 10 of about 2,095 (187)

Volcanism and basalt weathering drove Ordovician climatic cooling [PDF]

Nature Communications
Causal connections among major Ordovician environmental and biological events (i.e., long-term climatic cooling, Hirnantian Glaciation, Great Ordovician Biodiversification Event, and Late Ordovician Mass Extinction) remain in debate, and the hypothesis ...
He Zhao, Lei Zhang, Thomas J. Algeo, Zhengyi Lyu, Xiangdong Wang, Fang Hao   +5 more
doaj   +2 more sources

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

Geological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta, Saumitra Misra, Thembiso O. Basupi   +2 more
wiley   +1 more source

Ordovician graptolites from the basal part of the Palaeozoic transgressive sequence in the Karadere area, Zonguldak Terrane, NW Turkey [PDF]

Estonian Journal of Earth Sciences, 2014
The Karadere area to the east of Safranbolu in NW Anatolia is one of the very few localities in Turkey where the contact between the Cadomian basement and the Lower Palaeozoic transgressive succession is well exposed.
M. Cemal Göncüoglu, Valeri Sachanski, Juan Carlos Gutiérrez-Marco, Cengiz Okuyucu   +3 more
doaj   +1 more source

EVENT STRATIGRAPHY AND CORRELATION PROBLEMS OF THE ORDOVICIAN STRATA OF GORNY ALTAI AND SALAIR

Геодинамика и тектонофизика, 2021
Study of the Ordovician sedimentary sequences of Gorny Altai and Salair has revealed lithological and paleontological features correlating with global sedimentary events:(1) The Acerocare Regressive Event (an initial event in the Early Tremadocian);(2 ...
N. V. Sennikov, O. T. Obut, E. V. Lykova, A. V. Timokhin, R. A. Khabibulina, T. A. Shcherbanenko   +5 more
doaj   +1 more source

New geochronological constraints on Late Pleistocene glaciation in the southern Cadí Massif, SE Pyrenees

Journal of Quaternary Science, EarlyView.
ABSTRACT The Cadí Massif (42°17′09″ N, 1°38′11″ E; 2649 m a.s.l.) in the southeastern Pyrenees preserves clear evidence of Late Pleistocene glaciation, although previous research has focused almost exclusively on its northern slope. By contrast, the southern slope has remained largely unexplored.
M. Oliva, J. Ventura, A. Çiner, M. A. Sarıkaya, J. Bonsoms, K. M. Wilcken   +5 more
wiley   +1 more source

A talus rock glacier in Nantlle Valley, North Wales

Journal of Quaternary Science, EarlyView.
ABSTRACT Landforms comprising mixtures of fine and coarse sediment and deposited during late glacial times are ubiquitous in the British mountains. In many cases, their interpretation has often proved contentious; as a result, the non‐generic term discrete debris accumulations (DDA) has been used to describe them and, over the last 50 years, some have ...
Stephan Harrison, Ed Anderson
wiley   +1 more source

Depositional and Hydrological Relationships Between Buried Dead Ice and the Active Layer in the McMurdo Dry Valleys, Antarctica: A Study of Sediment Geochemistry and Cation Concentrations

Permafrost and Periglacial Processes, EarlyView.
ABSTRACT The McMurdo Dry Valleys, the largest ice‐free region in Antarctica, are home to a cold‐desert hydrologic system of glaciers, snowbanks, streams, and lakes. Freshwater is also stored as dead glacial ice, which is poorly constrained in terms of ion concentrations and interactions with both in situ and overlying sediments.
Matthew C. Witscheber, Kate M. Swanger
wiley   +1 more source

New Results From the Pre‐Pottery Neolithic Site of Al Uyaynah, Tabuk, in Northwestern Saudi Arabia

Arabian Archaeology and Epigraphy, EarlyView.
ABSTRACT Al Uyaynah is a low sandstone mound on an alluvial plain, long known for its extensive surface remains of stone‐built circular and rectangular structures. Following test excavations in 2012, more detailed excavation was undertaken in 2016 within one of the largest rectangular stone structures.
Khalid Alasmari, Stephanie F. Piper, Kirsten Grothe, W. Derek Hamilton, Delphine Joly, Penny Bickle, Geoff Bailey   +6 more
wiley   +1 more source

Clues of ancient incomplete lineage sorting during bivalve evolution undermine support for Heterodonta

Cladistics, EarlyView.
Abstract A long‐standing challenge in phylogenomics has been the resolution of relationships originated from ancient radiations. In these cases, phenomena such as incomplete lineage sorting can increase the support for conflicting resolutions. Most of the diversity in the Class Bivalvia originated during an Ordovician radiation; indeed, several deep ...
Alessandro Formaggioni, Takeshi Takeuchi, Mayuko Hamada, Kazuhiro Saito, Tatsuya Sakamoto, Noriyuki Satoh, Federico Plazzi, Marco Passamonti   +7 more
wiley   +1 more source

PERIODIZING GEOLOGICALLY OUTWITH (AND WITHOUT?) THE ANTHROPOCENE: PASTS, AGENCIES, AND THE TERRESTRIAL

History and Theory, EarlyView.
ABSTRACT As a periodization that is generally understood to refer to an era of Terrestrial relationships that developed with modernization and nuclearization, the Anthropocene cannot be applied simply to premodern histories and texts. However, it has introduced historians to geological periodization as a mode of describing periods of changed ...
Gwenffrewi J. Morgan
wiley   +1 more source