Results 21 to 30 of about 98 (95)

Low‐temperature dissociation of zircon in highly alkaline conditions: A cautionary note for studies on natural glasses of debated origin

Meteoritics &Planetary Science, Volume 60, Issue 7, Page 1573-1586, July 2025.
Abstract Dissociated zircon is largely used as a robust indicator of glasses generated by impact cratering and airbursts. The reaction of zircon dissociation, i.e. ‘ZrSiO4 → ZrO2 + SiO2’, requires high temperatures (>1670°C) only reached by extreme geological processes. Using high‐temperature experiments, this study shows that zircon can dissociate and
A. Musolino, B. Devouard, P. Rochette, P. Roperch, P. M. Zanetta, A.‐M. Seydoux‐Guillaume, A. Licht, D. Ferry, A. Campos   +8 more
wiley   +1 more source

Mid‐infrared detection and characterization of refractory inclusions in CM and CO chondrites: A non‐destructive approach for returned space samples

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 544-569, March 2025.
Abstract Refractory inclusions (RIs) in chondrites are widely used as tracers of early solar system formation conditions. In the context of sample‐return missions, a non‐destructive and non‐invasive analytical tool that can rapidly detect and characterize RIs in space samples during their early phase of study is highly needed.
Jean Charlier, Alice Aléon‐Toppani, Rosario Brunetto, Jérôme Aléon, Ferenc Borondics   +4 more
wiley   +1 more source

Heat sources for Variscan high‐temperature–low‐pressure metamorphism: Petrochronological constraints from the Trois Seigneurs massif, French Pyrenees

Journal of Metamorphic Geology, Volume 42, Issue 6, Page 867-907, August 2024.
Abstract High‐temperature–low‐pressure metamorphism is commonly associated with intermediate to felsic magmatism in continental orogenic belts. The heat budgets and transfer mechanisms responsible for such elevated temperatures and partial melting of the upper crust are uncertain.
Charlotte H. Connop, Andrew J. Smye, Joshua M. Garber, Tushar Mittal   +3 more
wiley   +1 more source

Coupled U–Pb and 40Ar/39Ar chronology of late‐stage intrusions at Elba Island (Italy) supports late Miocene long‐lived magma reservoirs in the Tyrrhenian upper crust

Terra Nova, Volume 36, Issue 4, Page 258-265, August 2024.
Abstract The late Miocene Monte Capanne and Porto Azzurro plutons are investigated by means of coupled U–Pb zircon and 40Ar/39Ar white mica dating to test the occurrence of long‐lived magmatic systems in the upper crust. Zircon crystallized for >1 Ma in both plutonic systems, with supersolidus conditions overlapping for ~220 ka indicating previously ...
F. Mazzarini, L. Bracciali, G. Musumeci, J. R. Wijbrans, K. Kuiper, M. S. A. Horstwood   +5 more
wiley   +1 more source

A Contiguous Taltson‐Thelon Margin Revisited

Geochemistry, Geophysics, Geosystems, Volume 25, Issue 7, July 2024.
Abstract The amalgamation of Laurentia was initiated along the western margin of the Rae craton. However, the tectonic setting that generated magmatic rocks along this margin has long been debated, with the Thelon tectonic zone in the north having formed in an arc setting, and the Taltson magmatic zone in the south variably attributed to either ...
J. A. Cutts, B. V. Dyck, M. G. Perrot, J. H. F. L. Davies, A. M. Osinchuk, D. Šilerová, R. A. Stern, M. Chiaradia, R. Canam   +8 more
wiley   +1 more source

Paleoarchean metamorphism in the Acasta Gneiss Complex: Constraints from phase equilibrium modelling and in situ garnet Lu–Hf geochronology

Journal of Metamorphic Geology, Volume 42, Issue 3, Page 373-394, April 2024.
Abstract The oldest known evolved (felsic) rocks on Earth (c. 4.03 Ga) are found in the Acasta Gneiss Complex (AGC) in north‐western Canada and represent a fundamental keystone in unravelling the geological processes governing crustal growth and differentiation during the Hadean and early Archean.
Jonas Kaempf, Tim E. Johnson, Chris Clark, Julian Alfing, Michael Brown, Pierre Lanari, Kai Rankenburg   +6 more
wiley   +1 more source

The Metamict State (Hoffmann, Roald) [PDF]

Journal of Chemical Education, 1989
This volume contains 47 of Hoffmann's poems, involving both his experience inside and outside the laboratory.
openaire   +1 more source

The first U–Pb age for shocked zircon from the Mien impact structure, Sweden, and implications for metamictization‐induced zircon texture formed during impact events

Meteoritics &Planetary Science, Volume 59, Issue 1, Page 211-241, January 2024.
Abstract Shocked zircon from impactites from the Mien impact structure, Sweden, has been investigated with the aim to date the impact event and correlate the degree of U–Pb age resetting with shock‐related microtextures. In situ U–Pb spot isotope analyses of granular and microporous–granular zircon grains from the impact melt rocks give an age of 120.0 
Maria Herrmann, Gavin G. Kenny, Josefin Martell, Martin J. Whitehouse, Carl Alwmark   +4 more
wiley   +1 more source

Mössbauer absorption in a metamict mineral [PDF]

Nature, 1975
THE technique and application of 57Fe Mossbauer spectroscopy to minerals have been discussed fully1–3 in the context of the determination of oxidation states, coordination numbers, and site symmetry and population. This report shows, with the particular example of metamict thoro-steenstrupine {Na2Ce(Mn,Fe,Ta)(La,Th,…)[(Si,P)O4]3H2}, that the Mossbauer ...
openaire   +1 more source

Metamict zircon from Mozambique

Bulletin of the Geological Society of Finland, 1985
Metamict zircon from granite pegmatites of Zambézia, Mozambique has been studied by annealing, microprobe, X-ray diffraction, DT and TG analysis, and IR spectroscopy. The specimens are contaminated by epitaxially intergrown xenotime. It is presumed that the lanthanoides, occur in the xenotime phase and only sparsely in the zircon.
openaire   +2 more sources