Results 61 to 70 of about 12,699 (236)

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

open access: yesMeteoritics &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   +6 more
wiley   +1 more source

Chronology, Local Stratigraphy, and Foreign Ejecta Materials at the Chang'e‐6 Landing Site: Constraints on the Provenance of Samples Returned From the Moon's Farside

open access: yesGeophysical Research Letters
China's Chang'e‐6 (CE‐6) mission has returned the first‐ever lunar farside samples from a mare plain on the southern Apollo basin floor. The crater statistics of the CE‐6 mare unit and the provenance of the samples are crucial in interpreting the CE‐6 ...
Luyuan Xu   +5 more
doaj   +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

open access: yesMeteoritics &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   +3 more
wiley   +1 more source

Layering Structures in the Porous Material Beneath the Chang'e‐3 Landing Site

open access: yesEarth and Space Science, 2020
The lunar penetrating radar (LPR) onboard the Chinese Chang'e‐3 (CE‐3) mission obtained high‐resolution profile data for the continuous ejecta deposits of the Ziwei crater.
Chunyu Ding   +9 more
doaj   +1 more source

Magnetic properties of geraisites, the first tektite strewn field identified in Brazil

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Geraisites are a newly recognized class of tektite from Brazil. They occur as centimeter‐sized, elongated to subspherical bodies scattered across surface gravel and shallow subsurface layers within a ~90‐km‐long strewn field extending between the municipalities of São João do Paraíso and Curral de Dentro, near the border between the states of ...
Melissa De Andrade Nunes   +7 more
wiley   +1 more source

Impact Failure of Planetary Materials: Lateral Field Ejecta Measurements using Particle Image Velocimetry

open access: yes, 2014
The dynamic fragmentation of a fine grained granitoid material has been examined. Target thicknesses ranged from 7 to 40 mm and impact energies from 12 to 2,500 J.
Rogers, Robert   +4 more
core   +1 more source

Ejecta Blankets at Small Craters on the Moon

open access: yesThe Planetary Science Journal
Impact-derived ejecta covers most of the lunar surface, originating from recent impacts through to the beginning of the geologic record. Despite how common ejecta is, accurate measurements of ejecta thickness are difficult to obtain, and existing ...
Trevor Austin   +2 more
doaj   +1 more source

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

open access: yesMeteoritics &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   +5 more
wiley   +1 more source

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

open access: yesMeteoritics &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   +8 more
wiley   +1 more source

Small-body deflection techniques using spacecraft: Techniques in simulating the fate of ejecta [PDF]

open access: yes, 2016
We define a set of procedures to numerically study the fate of ejecta produced by the impact of an artificial projectile with the aim of deflecting an asteroid. Here we develop a simplified, idealized model of impact conditions that can be adapted to fit
Yu, Yang   +4 more
core   +1 more source

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