Results 71 to 80 of about 29,661 (201)

Zircon U–Pb geochronology of paragneisses and biotite [PDF]

, 2008
Sensitive high-resolution ion microprobe U–Th–Pb age determinations on detrital and inherited zircon from the E ´ vora Massif (SW Iberian Massif, Portugal) provide direct evidence for the provenance of the Ossa–Morena Ediacaran basins (Se´rie Negra) and ...
Chichorro, Martim, Pereira, M. Francisco, Silva, Jose B., Williams, Ian S.   +3 more
core  

El volcanismo jurásico superior de la Formación Río Damas-Tordillo (33°-35,5°S): antecedentes su sobre petrogénesis, cronología, proveniencia e implicancias tectónicas [PDF]

, 2014
Los depósitos continentales y volcánicos de la Formación Rio Damas-Tordillo, Jurásico Superior, representan un período restringido de sedimentación continental dentro del registro mayormente marino de la Cuenca Neuquina.
Calderón, Sergio, Charrier González, Reynaldo, Ducea, Mihai Nicolae, Hoffman, Derek, Mescua, Jose Francisco, Oliveros, Verónica, Rossel, Pablo, Tapia, Felipe   +7 more
core   +2 more sources

Jadeite in Continental Subduction: Its Preservation, Breakdown and Pseudomorphic Replacement in Erzgebirge UHP Gneisses

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The absence of jadeite in regions where subduction of continental crust has been documented by other high‐pressure (HP) or ultrahigh‐pressure (UHP) minerals is striking. This study presents only the second discovery of jadeite in the crystalline rocks of the Erzgebirge, a region known for its occurrences of microdiamond, coesite and omphacite ...
Ondrej Lexa, Martin Racek, Petr Jeřábek, Benjamin Paddon   +3 more
wiley   +1 more source

U‐Pb Geochronology of Paleosol Carbonate Cements by LA‐ICP‐MS: A Proof of Concept and Strategy for Dating the Terrestrial Record

Geochemistry, Geophysics, Geosystems
This study investigates the potential of laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U‐Pb dating for carbonate nodules in the Late Triassic Ischigualasto Formation of northwestern Argentina.
L. E. Aguirre Palafox, A. Möller, N. M. McLean, G. A. Ludvigson, C. E. Colombi, I. P. Montañez   +5 more
doaj   +1 more source

Variable Sr Diffusion and Implications for Rb–Sr Biotite Geochronology

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The rubidium–strontium (Rb–Sr) system has a long pedigree as a geochronological tool that relies on the application of an isochron approach. In particular, biotite contains strongly radiogenic Rb–Sr isotopes, and thus can yield meaningful crystallisation or cooling ages via this approach. However, the response of the Rb–Sr system in biotite to
Riley Rohrer, Christopher L. Kirkland, Hugo Olierook, Tim Johnson, Katy Evans   +4 more
wiley   +1 more source

Impact and Correction of Analytical Positioning on Accuracy of Zircon U-Pb Dating by SIMS

Frontiers in Chemistry, 2020
Secondary ion mass spectrometry (SIMS) is one of the most important analytical tools for geochronology, especially for zircon U-Pb dating. Due to its advantages in spatial resolution and analytical precision, SIMS is the preferred option for multi-spot ...
Yu Liu, Yu Liu, Qiu-Li Li, Qiu-Li Li, Qiu-Li Li, Xiao-Xiao Ling, Xiao-Xiao Ling, Guo-Qiang Tang, Guo-Qiang Tang, Jiao Li, Jiao Li, Xian-Hua Li, Xian-Hua Li, Xian-Hua Li   +13 more
doaj   +1 more source

Early Cambrian U-Pb zircon age and Hf-isotope data from the Guasayán pluton, Sierras Pampeanas, Argentina: implications for the northwestern boundary of the Pampean arc [PDF]

, 2016
An Early Cambrian pluton, known as the Guasayán pluton, has been identified in the central area of Sierra de Guasayán, northwestern Argentina. A U?Pb zircon Concordia age of 533 ± 4 Ma was obtained by LA-MC-ICP-MS and represents the first report of ...
Alasino, Pablo Horacio, Baldo, Edgardo Gaspar Agustín, Basei, Miguel A. S., da Costa Campos Neto, Mario, Dahlquist, Juan Andrés, Rapela, Carlos Washington, Uran, Gimena Mariel, Verdecchia, Sebastián Osvaldo, Zandomeni, Priscila Soledad   +8 more
core   +2 more sources

P–T Modelling Constrains the Depth of Emplacement of the Porto Azzurro Pluton and Implies Minor Exhumation Caused by the Zuccale Fault (Island of Elba, Italy)

Journal of Metamorphic Geology, EarlyView.
ABSTRACT Understanding the pressure of emplacement of granitic intrusions is crucial to understanding the exhumation history of plutons and constraining the tectonic setting of magma emplacement. However, P–T and geochronological constraints from exhumed plutons are often characterized by large uncertainties, especially in shallow crustal settings with
Samuele Papeschi, Marco Bonini, Matteo Lupi, Chiara Del Ventisette, Domenico Montanari   +4 more
wiley   +1 more source

Evidence from Rb–Sr mineral ages for multiple orogenic events in the Caledonides of Shetland, Scotland [PDF]

, 2015
Shetland occupies a unique central location within the North Atlantic Caledonides. Thirty-three new high-precision Rb–Sr mineral ages indicate a polyorogenic history.
Bird, A. F., Strachan, R. A., Thirlwall, M. F., Walker, S.   +3 more
core   +3 more sources

Ductile Extrusion Triggered by Continental Collision in NE Brazil

Terra Nova, EarlyView.
ABSTRACT The Borborema Province in northeastern Brazil hosts one of the world's largest strike‐slip shear zone networks, active during the late Neoproterozoic assembly of West Gondwana. Whether these shear zones initiated during active continental collision or as a post‐orogenic response to far‐field stresses remains debated.
L. R. Tesser, C. E. Ganade, C. R. Cioffi, J. B. Forshaw, M. Hueck, E. Celis, M. A. S. Basei   +6 more
wiley   +1 more source