Results 41 to 50 of about 7,715 (221)

New Magnetite Reference Material for SIMS δ18O Measurements and a Study of Precision and Accuracy Due to Crystal Orientation Effects

Geostandards and Geoanalytical Research, EarlyView.
Key Points A new magnetite reference material (PF21mt) is available for δ18O measurements by SIMS. Reproducibility of measurement results in two laboratories suggest orientation bias of ±2‰ (2s) at 20 keV. Repeatability improves to ±1‰ (2s) when using a 13 keV protocol, suggesting reduced orientation bias. In situ isotope ratio measurements provide the
Michelle Ulrich, Daniela Rubatto, Maria Rosa Scicchitano, Benita Putlitz, Thomas Bovay   +4 more
wiley   +1 more source

Deep fault sliding rates for Ka-Ping block of Xinjiang based on repeating earthquakes

Open Geosciences
The seismically active Ka-Ping Block within Xinjiang, China, represents a zone of potential earthquake hazards, and existing surface measurements cannot fully reflect the area’s sub-surface slip rates.
Gao Chaojun, Liu Daiqin, Li Jie, Song Chunyan, Yideresi Gulizinati, Yushan Ailixiati   +5 more
doaj   +1 more source

A Common Reference Material for Mass‐Dependent Sn Isotope Compositions: An Inter‐Laboratory Calibration Approach

Geostandards and Geoanalytical Research, EarlyView.
Key Points We recommend using the notation δ122/118SnNIST SRM 3161a for mass‐dependent Sn isotope data. We derived conversion factors relative to NIST SRM 3161a for Puri Sn CEZA (0.132 ± 0.011‰), Sn Lyon (0.229 ± 0.016‰), Sn IPGP (0.162 ± 0.018‰). Tin isotope compositions are presented for SPEX CertiPrep Sn and nine USGS reference materials.
Aurélia C.E. Meister, Manuela A. Fehr, Quentin Amet, Gerhard Brügmann, Caroline Fitoussi, Matthias Friebel, Weiqiang Li, Frederic Moynier, Jia‐Xin She, Xueying Wang, Maria Schönbächler   +10 more
wiley   +1 more source

Tectonic control on great earthquake periodicity in south-central Chile

Communications Earth & Environment
Multi-millennial records of great megathrust earthquakes have highlighted differences in periodicity and recurrence behavior. Understanding tectonic processes responsible for these differences is relevant for fault mechanics and hazard models.
Diego Aedo, Daniel Melnick, Marco Cisternas, Dominik Brill   +3 more
doaj   +1 more source

Timing of Metamorphism and Deformation in the Neoarchean Quetico Metasedimentary Belt, Superior Craton, Constrained by Garnet Trace‐Element Mapping and Lu–Hf Geochronology

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The Quetico subprovince of the Superior Province is among the largest metasedimentary belts globally and provides evidence of tectonic processes at play during the final stages of Archean cratonization. Although previous studies have shown that deformation and metamorphism of the 2.7‐Ga turbiditic protolith resulted in regional subvertical ...
Adrian G. Rehm, Antoine Godet, Doug Tinkham, Carl Guilmette, Matthijs A. Smit   +4 more
wiley   +1 more source

Garnet–Clinopyroxene Double‐Layered Coronae in a Metagabbronorite From the High‐Grade Metamorphic Gföhl Unit, Moldanubian Zone

Journal of Metamorphic Geology, EarlyView.
ABSTRACT This study investigates garnet–clinopyroxene double‐layered coronae in a metagabbronorite from the high‐grade metamorphic Gföhl Unit (Bohemian Massif). The coronae formed at the interfaces between relic magmatic orthopyroxene, still preserved in the cores of the coronae, and the plagioclase‐rich rock matrix.
Rene Asenbaum, Tereza Nemeškalová, Martin Racek, Vojtěch Janoušek, Julian Portenkirchner, Rainer Abart   +5 more
wiley   +1 more source

The making of pure quartzose sand in continental interiors: Paraná River (Brazil and Argentina)

Sedimentology, EarlyView.
ABSTRACT As part of a comprehensive project on sedimentary processes in South America, this study focuses on sediment generation in the intracratonic Paraná Basin and monitors the evolution of sand composition along the Paraná River from central Brazil to the Río de la Plata estuary in Argentina.
Eduardo Garzanti, Marta Barbarano, Mara Limonta, Guido Pastore, Pieter Vermeesch, Giovanni Vezzoli   +5 more
wiley   +1 more source

Petrology and tectonic settings of the Sarcheshmeh porphyry copper deposit with emphasis on granodiorite and quartz eye porphyry

Journal of Economic Geology, 2020
Introduction The Sarcheshmeh porphyry copper deposit (PCD) and other porphyry deposits occur in the the most important metallogenic belt in Iran, i.e. the Urumieh-Dokhtar magmatic belt (UDMB).
Mohammad Maanijou, Mohammad Mostaghimi, Mehdi Abdollahi Riseh, Ali Asghar Sepahi   +3 more
doaj   +1 more source

Horizontal mantle flow controls subduction dynamics

Scientific Reports, 2017
It is generally accepted that subduction is driven by downgoing-plate negative buoyancy. Yet plate age –the main control on buoyancy– exhibits little correlation with most of the present-day subduction velocities and slab dips. “West”-directed subduction
E. Ficini, L. Dal Zilio, C. Doglioni, T. V. Gerya   +3 more
doaj   +1 more source

Reawakening of large earthquakes in south central Chile: The 2016 Mw 7.6 Chiloé event

Geophysical Research Letters, 2017
On 25 December 2016, the Mw 7.6 Chiloé earthquake broke a plate boundary asperity in south central Chile near the center of the rupture zone of the Mw 9.5 Valdivia earthquake of 1960. To gain insight on decadal‐scale deformation trends and their relation
S. Ruiz, M. Moreno, D. Melnick, F. delCampo, P. Poli, J. C. Baez, F. Leyton, R. Madariaga   +7 more
doaj   +1 more source