Results 111 to 120 of about 5,174 (245)

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

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

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

Meteoritics &Planetary Science, EarlyView.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska, Sanna Alwmark, Mikael Calner, Sylvain Richoz, Jens Ormö, Erik Sturkell, Carl Alwmark   +6 more
wiley   +1 more source

Atomic structure and water arrangement on K-feldspar microcline (001)

Nanoscale
Investigating the water structure at the K-feldspar microcline (001) surface is a prerequisite for understanding fundamental surface processes.
Tobias Dickbreder, Franziska Sabath, Bernhard Reischl, Rasmus V. E. Nilsson, Adam S. Foster, Ralf Bechstein, Angelika Kühnle   +6 more
openaire   +5 more sources

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

Araguainha Dome, Brazil: A polygonal impact structure due to a complex pre‐impact regional structural framework

Meteoritics &Planetary Science, EarlyView.
Abstract We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre‐impact structures in this region may have had any influence on the first‐order formation and morphostructure of the Araguainha impact structure (AIS).
Renato B. Bernardes, Wolf U. Reimold, Roger L. Gibson, Julia B. Curto Ma, Adolfo B. Silva, Natalia Hauser   +5 more
wiley   +1 more source

Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure

Meteoritics &Planetary Science, EarlyView.
Abstract Hummeln is a simple impact structure located in south‐eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln‐1 with a focus on impact metamorphism and the impact process.
S. Alwmark, J. Granbom, P. Ahlberg, M. Calner, S. Richoz, K. J. Gajewska, W. R. Hyde, K. Ljung, C. Alwmark   +8 more
wiley   +1 more source

Frictional Properties of Feldspar‐Chlorite Gouges and Implications for Fault Reactivation in Hydrothermal Systems

Earth and Space Science
As a particularly common mineral in granites, the presence of feldspar and feldspar‐chlorite gouges at hydrothermal conditions has important implications in fault strength and reactivation.
Zijuan Hu, Chongyuan Zhang, Lei Zhang, Derek Elsworth, Fengshou Zhang, Quan Gan, Huiru Lei, Manchao He, Leihua Yao   +8 more
doaj   +1 more source

Impact‐diagnostic criteria for use in confirming a meteorite impact origin of terrestrial geological structures: Recommendations by the Impact Cratering Committee of the Meteoritical Society

Meteoritics &Planetary Science, EarlyView.
Abstract The framework of the Impact Cratering Committee (ICC) of the Meteoritical Society was approved in 2020, with the first committee members appointed in 2023. The ICC has a mandate to (1) approve, maintain, and update a database of confirmed terrestrial meteorite impact structures, (2) define and regularly update the criteria used for ...
A. J. Cavosie, S. Alwmark, D. Baratoux, G. Consolmagno, L. Ferrière, S. Goderis, N. Hauser, T. Kenkmann, C. Koeberl, G. R. Osinski, A. E. Pickersgill, M. Schönbächler   +11 more
wiley   +1 more source

Geology of the central uplift of the Kamestastin Lake impact structure, Labrador, Canada

Meteoritics &Planetary Science, EarlyView.
Abstract The ~28 km Kamestastin (Mistastin) Lake impact structure is a relatively well‐preserved and well‐exposed complex impact structure. The central uplift of this structure is accessible as two islands in the middle of Kamestastin Lake. We present an updated, detailed geological map and description of Horseshoe and Bullseye islands that provides ...
A. C. Singleton, G. R. Osinski
wiley   +1 more source