Results 51 to 60 of about 1,722,612 (173)

Orthodentine‐osteodentine and osteocytic‐anosteocytic transition inferred from Silurian stem chondrichthyan dermal jawbones with ever‐white teeth overgrown by brown denticles

Developmental Dynamics, EarlyView.
Abstract Background The dentigerous jawbones of a 423‐million‐year‐old stem chondrichthyan (ischnacanthid acanthodian) carry a characteristic combination of multi‐row non‐shedding white teeth with brownish overgrowing denticles. The color distinction makes it a good model for observing the interaction between two odontode lineages, but the nature of ...
Jia‐Cih Kang, Henning Blom, Tiiu Märss, Donglei Chen   +3 more
wiley   +1 more source

On the Upper Ordovician unconformity in the Pyrenees : new evidence from the La Cerdanya area [PDF]

, 2007
In recent years, contradictory reports about whether or not an unconformity exists at the base of the Upper Ordovician succession of the Pyrenees have been made.
Casas, J.M., Casas Tuset, Josep Maria, Casas, J., Fernández, O., Fernández, Òscar   +4 more
core   +1 more source

Post‐Stimulation Hydraulic Response and Productivity Constraints of a Low‐Productivity Carbonate Geothermal Well in the Small Intramontane Basin, Beijing Piedmont, North China

Energy Science &Engineering, EarlyView.
Formed ~1.4 Ga, the carbonate reservoir of the Jixian System is a key geothermal reservoir in northern China. Differential basin–mountain evolution since the Cenozoic led to distinct reservoir‐forming histories; consequently, this same reservoir shows marked productivity contrasts between intramontane basins and the large rift Bohai Bay Basin ...
Chuanqing Zhu, Kefu Li, Wansen Yao, Wanqing Geng, Yonghui Huang, Shu Jiang, Nansheng Qiu   +6 more
wiley   +1 more source

Geochemistry and Geochronology of Magmatic Rocks in Southwestern and Northeastern Cambodia: Implications for the Tectonic Evolution and Metallogenesis of the Loei Fold Belt

Geological Journal, EarlyView.
The composition of intrusive rocks suggests that the magma was likely generated in a subduction‐related setting. The arc crustal thickness in the Phnom Sro Ngam and Halo Prospects was probably < 40 km during emplacement. Zircon U–Pb age range indicates a correlation with Loei Fold Belt magmatic activity.
Sirisokha Seang, Khin Zaw, Kakda Kret, Ivan Belousov, Kotaro Yonezu, Koichiro Watanabe, Charles Makoundi   +6 more
wiley   +1 more source

First record of ostracods from the Upper Ordovician red-coloured marine sandstones of the Tierekeawati Formation in Tarim Basin, NW China: implications on palaeoenvironment and palaeobiogeography

Journal of Palaeogeography, 2020
Ostracods are described for the first time from the red-coloured marine sandstones of Arisu section (Arisu red beds) of the Upper Ordovician Tierekeawati Formation in Kalpin area of northwestern Tarim Basin, Xinjiang Uygur Autonomous Region (Xinjiang ...
Jun-Jun Song, Yi-Xin Shen, Peng Tang, Xiao-Le Zhang, Qi-Jian Li, Zheng-Jiang Luo   +5 more
doaj   +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

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

Bryozoan‐Rich Carbonate Units of the Erfoud Area (SE Morocco) Record Latest Katian to Early Hirnantian Interglacial Intervals

Geological Journal, EarlyView.
In this study, we re‐examine the depositional architecture of the Erfoud limestone in Morocco. Introducing new biostratigraphic constraints from chitinozoan assemblages, we show that Katian to Hirnantian bryozoan‐pelmatozoan meadows reflect flooding events linked to a series of interglacial transgressions known to have occurred immediately prior to the
Philippe Razin, Jean‐François Ghienne, Amira Meddour, Lorena Tessitore, Thijs R. A. Vandenbroucke   +4 more
wiley   +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