Results 61 to 70 of about 516 (186)

The Grand St Bernard‐Briançonnais Nappe System and the Paleozoic Inheritance of the Western Alps Unraveled by Zircon U‐Pb Dating [PDF]

Tectonics, 2017
AbstractThe continental crust involved in the Alpine orogeny was largely shaped by Paleozoic tectono‐metamorphic and igneous events during oblique collision between Gondwana and Laurussia. In order to shed light on the pre‐Alpine basement puzzle disrupted and reamalgamated during the Tethyan rifting and the Alpine orogeny, we provide sensitive high ...
Bergomi, MA, Dal Piaz, GV, Malusà, MG, Monopoli, B, Tunesi, A   +4 more
openaire   +1 more source

Potassium isotopic compositions and exposure ages of evolved and silica‐rich achondrites

Meteoritics &Planetary Science, EarlyView.
Abstract Some of the oldest igneous rocks in the Solar System include evolved and silica‐rich achondrites that originate from parent bodies less than 1000 km in diameter, referred to as planetesimals. While Earth was initially in a molten state and required continental crust formation and plate tectonics to generate andesite bulk compositions, evolved ...
Z. Vaci, Z. Tian, P. Koefoed, M. Habermann, M. Humayun, K. Ziegler, H. Busemann, D. Krietsch, J. M. D. Day, K. Wang   +9 more
wiley   +1 more source

Characterization of coesite‐bearing impact melt glass from the Hapcheon crater, Korea: Trimodal phase architecture, shock metamorphism, and implications for 40Ar/39Ar geochronology

Meteoritics &Planetary Science, EarlyView.
Abstract We present the first micrometer‐scale, phase‐resolved compositional characterization of impact melt glass from the Hapcheon crater (~1.4 km apparent diameter), the first confirmed impact structure on the Korean Peninsula, integrating EPMA‐WDS (5 μm spot), confocal Raman spectroscopy (<1 μm spot), XRD, and 40Ar/39Ar step‐heating geochronology ...
Jin‐Young Lee, Jeongmin Kim, Sei‐Sun Hong   +2 more
wiley   +1 more source

Spatial and temporal evolution of a coastal erg margin: the Middle Jurassic Page Sandstone, southern Utah, USA

Sedimentology, EarlyView.
ABSTRACT Aeolian deflationary events are erosive to static stages where sediment supply is insufficient to support bedform migration and preservation in the rock record. In the vicinity of shallow‐marine environments, inland rises of relative water table and associated generation of deflationary super surfaces may be driven by the onset of ...
Victor J. P. Hême de Lacotte, Chester H. C. Davies, Briony J. Bowler, Stuart M. Clarke, Thomas J. H. Dodd   +4 more
wiley   +1 more source

Characteristics of ∼40 Ma Mafic Rocks in North Tibet and Their Tectonic Implications

Geochemistry, Geophysics, Geosystems
Several magmatic belts are present in the Tibetan Plateau. Among these, the Qiangtang magmatic belt in North Tibet remains elusive. In particular, the petrogenesis, magma source, and tectonic implications of the ultramafic to mafic rocks in the North ...
Shifeng Wang, Licai Song, Shengting Zhang, Weifeng Xiao   +3 more
doaj   +1 more source

Zircon compositional systematics from Devonian oxidized I-type granitoids: examination of porphyry Cu fertility indices in the New Brunswick Appalachians, Canada

Frontiers in Earth Science
Zircon is a common, widely distributed accessory mineral in most igneous rocks and its refractory nature records magmatic evolution in terms of oxygen and U-Th-Pb isotopes, and trace-element contents all of which reflect the intrinsic physio-chemical ...
Fazilat Yousefi, David R. Lentz, Christopher R. M. McFarlane, James A. Walker, Kathleen G. Thorne   +4 more
doaj   +1 more source

New SHRIMP ages for Ladakh and Karakoram Batholiths - inherited zircons indicate involvement of older crust

Himalayan Journal of Sciences, 1970
DOI = 10.3126/hjs.v5i7.1230 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p ...
Ahmad, T, White, L, Forster, M, Ireland, TR, Lister, G   +4 more
openaire   +3 more sources

Effect of chemical abrasion of zircon on SIMS U–Pb, δ¹⁸O, trace element, and LA-ICPMS trace element and Lu–Hf isotopic analyses [PDF]

Geochronology
This study assesses the effect of chemical abrasion on in situ mass spectrometric isotopic and elemental analyses in zircon. Chemical abrasion improves the U–Pb systematics of SIMS (secondary ion mass spectrometry) analyses of reference zircons, while ...
C. Kooymans, C. W. Magee Jr., K. Waltenberg, N. J. Evans, S. Bodorkos, Y. Amelin, Y. Amelin, S. L. Kamo, T. Ireland, T. Ireland   +9 more
doaj   +1 more source

Cryptic Superfine Placer Gold Populations, Round Hill Mine, Southern New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 3, September 2026.
Superfine (50–<1 µm) detrital gold and platinum group mineral (PGM) particles at the Round Hill mine near Foveaux Strait were locally derived (<20 km) from as‐yet undefined basement sources. This superfine component contrasts with the dominant coarser (typically >100 µm) gold and PGM particles at the mine that have been transported for >100 km in ...
Marshall Palmer, Dave Craw
wiley   +1 more source

Reidite Formation From Zircon Subjected to 20, 40, and 60 GPa Shock Experiments

Journal of Raman Spectroscopy, Volume 57, Issue 8, Page 1392-1406, August 2026.
Structure disordering as a result of shock pressure: In zircon shocked from 20 to 60 GPa, the shock‐induced structural disorder increases with increasing shock pressure (gray area). Shock disorder of zircon is an integral part of its transformation to reidite: Reidite occurs after amorphous material.
Dmitry A. Zamyatin, Elizaveta Kovaleva
wiley   +1 more source