Results 71 to 80 of about 1,938 (228)

Determining impact angle from the spatial distribution of shock metamorphism: A case study of the Gosses Bluff (Tnorala) impact structure, Australia

Meteoritics &Planetary Science, EarlyView.
Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews, Auriol S. P. Rae, Thomas Kenkmann, Nicholas E. Timms, Aaron J. Cavosie, Marian B. Holness   +5 more
wiley   +1 more source

Establishing a protocol for the selection of zircon inclusions in garnet for Raman thermobarometry

, 2020
The structural and chemical properties of zircon inclusions in garnet megablasts from the Dora Maira Massif (Western Alps, Italy) were characterized in detail using charge contrast imaging, Raman spectroscopy, and laser ablation inductively coupled ...
Hermann J., Mihailova, Boriana, Campomenosi, Nicola, Campomenosi N., Alvaro M., Hermann, Joerg, Rubatto D., Rubatto, Daniela, Alvaro, Matteo, Scambelluri M., Scambelluri, Marco, Mihailova B.   +11 more
core   +1 more source

Vertical profiling of shock attenuation at the Rochechouart impact structure, France

Meteoritics &Planetary Science, EarlyView.
Abstract Rochechouart, south‐west France, is a complex impact structure. Here, we present the first report of shock barometry of quartz from what are likely parautochthonous basement units at depth, based on samples from the 2017 C.I.R.I.R drilling campaign. The crystallographic orientations of 725 sets of PDFs in 512 quartz grains in samples from four
P. Struzynska, S. Alwmark, C. Alwmark, M. H. Poelchau, P. Lambert   +4 more
wiley   +1 more source

Data analysis of the U–Pb geochronology and Lu–Hf system in zircon and whole-rock Sr, Sm–Nd and Pb isotopic systems for the granitoids of Thailand

Data in Brief, 2018
This data article provides zircon U–Pb and Lu–Hf isotopic information along with whole-rock Sm–Nd, Sr and Pb isotopic geochemistry from granitoids in Thailand.
Romana E.C. Dew, Simon Nachtergaele, Alan S. Collins, Stijn Glorie, John Foden, Johan De Grave, Morgan L. Blades, Christopher K. Morley, Noreen J. Evans, Brandon L. Alessio, Pitsanupong Kanjanapayont, Rosalind King, Punya Charusiri   +12 more
doaj   +1 more source

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

Static recrystallization of shocked calcite in Ries impact breccias

Meteoritics &Planetary Science, EarlyView.
Abstract Calcite is prone to chemical and microstructural modifications, especially after having been strained at high stresses and strain rates, as during hypervelocity impact events. These modifications include precipitation from pore fluid as well as replacement of strained volumes by recrystallization. In calcite aggregates of a metagranite breccia
Claudia A. Trepmann, Fabian Dellefant, Lina Seybold, Wolfgang W. Schmahl, Elena Sturm, Daniel Weidendorfer, Sandro Jahn, Iuliia V. Sleptsova, Stuart A. Gilder   +8 more
wiley   +1 more source

Polymict melt‐bearing breccia dikes in the Morokweng impact structure formed by slip‐induced mechanical mixing of pseudotachylite and cataclasite along large‐displacement impact faults

Meteoritics &Planetary Science, EarlyView.
Abstract A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter‐ to meter‐wide clastic‐matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter‐ to centimeter ‐size ...
Roger L. Gibson, S'lindile S. Wela, Leonidas C. Vonopartis, Marco A. G. Andreoli   +3 more
wiley   +1 more source

Confirming the impact origin of the São Miguel do Tapuio structure, northeastern Brazil

Meteoritics &Planetary Science, EarlyView.
Abstract The São Miguel do Tapuio structure (SMT) is a remarkable, nearcircular feature of about 21 km diameter, centered at 5°37.6′ S, 41°23.3′ W in Piauí state, northeastern Brazil. The structure is located within the sedimentary strata of the Paleozoic–Mesozoic Parnaíba Basin and predominantly comprises sandstones of the Devonian Pimenteiras and ...
Alvaro Penteado Crósta, Neivaldo Araújo de Castro, Marcos Alberto Rodrigues Vasconcelos, Airton Natanael Coelho Dias, Ludovic Ferrière, Wolf Uwe Reimold, Ana Maria Góes, Jackson Alves Martins, Liliana Sayuri Osako, Raimundo Mariano Gomes Castelo Branco   +9 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