1-20 OF 172 RESULTS FOR

ejecta

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Journal Article
Journal: Geology
Published: 01 December 2021
Geology (2022) 50 (3): 311–315.
... the first detailed description of shock-triggered formation of skeletal quartz aggregates from silica-rich fluids occurring in impact melt masses from the Kamil crater (Egypt) ejecta curtain. The features of these aggregates support the idea that at local compositional heterogeneities such as fluid...
FIGURES | View All (4)
Journal Article
Published: 01 December 2021
Journal of the Geological Society (2022) 179 (3): jgs2021-055.
...M.J. Pankhurst; C.J. Stevenson; B.C. Coldwell Abstract Meteorite impacts load the atmosphere with dust and cover the Earth's surface with debris. They have long been debated as a trigger of mass extinctions throughout Earth history. Impact winters generally last <10 0 years, whereas ejecta...
FIGURES | View All (4)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(29)
EISBN: 9780813795508
..., and the morphology of the ejecta (single, double, or multiple layered ejecta rampart sinuous [LERS], or low-aspect-ratio layer ejecta [LARLE]). In total, 8445 LERS craters, 24,530 partially buried craters, 55,309 secondary craters, and 288,155 craters in the category “standard” were identified. Our assessment...
FIGURES | View All (8)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(16)
EISBN: 9780813795508
... front and a conspicuous central region of the cloud. The front extends continuously, while the self-luminous inner area between 2 and 3 µs is locally stable in terms of its position (above the crater) and intensity. After 3 µs, the less hot ejecta curtain appears (see impact point in Fig. 5 , time...
FIGURES | View All (5)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(17)
EISBN: 9780813795508
... crater through characterization of microstructures in a centimeter-sized clast of shocked nonporous sandstone ejecta, previously described as containing quartz grains with PDFs and PFs, coesite, stishovite, diamond, and lechatelierite. Orientation analysis by electron backscatter diffraction (EBSD...
FIGURES | View All (7)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(02)
EISBN: 9780813795508
...., 2019a) impact structures. The Australian impact cratering record also includes ejecta layers, such as proximal (impact glass, suevite, lithic breccias) and distal (tektites, microtektites, microkrystites, and vapor condensates) ejecta (e.g., French, 1998 ; Glass and Simonson, 2013 ; Smith et al...
FIGURES | View All (8)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(28)
EISBN: 9780813795508
... as double-layer ejecta (DLE) craters, whereas Tenoumer, Lonar, and Meteor craters can be classified as single-layer ejecta (SLE) craters. Tenoumer and Meteor craters show rampart as well as common lunar-like ejecta characteristics within their ejecta blankets and, thus, appear to be hybrid craters...
FIGURES | View All (11)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(12)
EISBN: 9780813795508
... ABSTRACT Early Archean spherule layers, widely accepted to represent distal ejecta deposits from large-scale impact events onto the early Earth, have been described from several stratigraphic levels of the Barberton greenstone belt in South Africa. Recently, exploration drilling at the Fairview...
FIGURES | View All (15)
Series: GSA Special Papers
Published: 02 August 2021
DOI: 10.1130/2021.2550(08)
EISBN: 9780813795508
... ABSTRACT A combined petrographic and chemical study of ejecta particles from the Cretaceous-Paleogene boundary sequence of El Guayal, Tabasco, Mexico (520 km SW of Chicxulub crater), was carried out to assess their formation conditions and genetic relation during the impact process...
FIGURES | View All (12)
Journal Article
Published: 16 October 2020
Journal of the Geological Society (2021) 178 (1): jgs2020-056.
... of shocked quartz led to the hypothesis that the Stac Fada Member represents part the continuous ejecta blanket of a meteorite impact crater, the location of which was, and remains, unknown. In this paper, we confirm the presence of shock-metamorphosed and -melted material in the Stac Fada Member; however...
FIGURES | View All (8)
Journal Article
Journal: Geology
Published: 07 October 2020
Geology (2021) 49 (2): 201–205.
... compression. However, there is no broad consensus among empirical, experimental, and theoretical studies on the nature of the polymorphic transformation. Here we decipher a multistage history of reidite growth recorded in a zircon grain in distal impact ejecta (offshore northeastern United States) from the ca...
FIGURES | View All (4)
Journal Article
Journal: Economic Geology
Published: 01 May 2020
Economic Geology (2020) 115 (3): 505–525.
.... , and Koeberl , C. , 2017 , Chromium isotope evidence in ejecta deposits for the nature of Paleoproterozoic impactors : Earth and Planetary Science Letters , v. 460 , p. 105 – 111 . Naldrett , A.J. , 1969 , A portion of the system Fe-S-O between 900 and 1080°C and its application to sulfide...
FIGURES | View All (13)
Journal Article
Published: 17 January 2020
Journal of the Geological Society (2020) 177 (2): 449–451.
... the breccia clearly were reworked from the lapilli-rich beds in the upper part of the Stac Fada Member. Still more conclusively, a metre-scale gneiss clast in the spallation ejecta layer beneath the Stac Fada Member is abruptly truncated at the unconformity surface ( Fig. 2 ). Fig. 2. The Stoer...
FIGURES
Journal Article
Published: 17 January 2020
Journal of the Geological Society (2020) 177 (2): 452–454.
... by Graham Shields References Amor , K. , Hesselbo , S.P. et al. 2019 . The Mesoproterozoic Stac Fada proximal ejecta blanket, NW Scotland: constraints on crater location from field observations, anisotropy of magnetic susceptibility petrography and geochemistry . Journal...
FIGURES
Journal Article
Published: 13 December 2019
Journal of the Geological Society (2020) 177 (2): 443–446.
... of the Stoer Group of NW Scotland as a proximal ejecta blanket of late Mesoproterozoic age ( Amor et al. 2008 ) has led to the search for the impact crater from which it originated. One prominent suggestion has been that this crater lies buried beneath east-central Sutherland, broadly centred on the village...
FIGURES
Journal Article
Published: 13 December 2019
Journal of the Geological Society (2020) 177 (2): 447.