Results 151 to 160 of about 3,790 (296)

Search for impact ejecta at the Paleocene–Eocene boundary

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Almost 10 years have passed since microtektites and microkrystites were reported for the Paleocene–Eocene (P–E) boundary in drill cores and outcrop in New Jersey and in ODP Hole 1051B in the western North Atlantic. The glassy spherules were interpreted to reflect an impact trigger for the Paleocene–Eocene Thermal Maximum (PETM).
Birger Schmitz   +6 more
wiley   +1 more source

Static recrystallization of shocked calcite in Ries impact breccias

open access: yesMeteoritics &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   +8 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

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

Direct evidence for magnetohydrodynamic disk winds driving rotating outflows in protostar HOPS 358. [PDF]

open access: yesNat Commun
Kim CH   +6 more
europepmc   +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

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

open access: yesMeteoritics &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   +9 more
wiley   +1 more source

Magnetogravitationally regulated streamer accretion onto a class 0 protostellar system. [PDF]

open access: yesSci Adv
Huang B   +19 more
europepmc   +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

Vector beam mapping at millimeter wavelengths using a robot arm

open access: yes
Many experimental efforts are striving to provide deep maps of the cosmic microwave background (CMB) to shed light on key questions in modern cosmology.
Gudmundsson, Jón E.,   +2 more
core   +1 more source

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