Results 141 to 150 of about 13,652 (300)
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 +5 more
wiley +1 more source
Asteroid flux and impact cratering rate on Venus [PDF]
By the end of 1990, 65 Venus-crossing asteroids were recognized; these represent 59 percent of the known Earth-crossing asteroids. Further studies, chiefly numerical integrations of orbit evolution, may reveal one or two more Venus crossers among the set
Shoemaker, C. S. +2 more
core +1 more source
Vertical profiling of shock attenuation at the Rochechouart impact structure, France
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 +4 more
wiley +1 more source
Search for impact ejecta at the Paleocene–Eocene boundary
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
‘reportless places’: Janet Malcolm and Collage
Critical Quarterly, EarlyView.
Natalie Ferris
wiley +1 more source
A geophysical investigation of the Roter Kamm impact crater, Namibia
Abstract The Roter Kamm impact crater is located in the southern Namib Desert. The crater has a diameter of 2.5 km and belongs to the category of simple, bowl‐shaped impact craters, with an elevated rim of fractured target rock. The crater's interior is completely buried beneath sediments, preventing extensive surface investigations of the bedrock ...
Hannah Nienhaus +6 more
wiley +1 more source
Scaling laws of plume-induced granular cratering. [PDF]
Gorman MT +6 more
europepmc +1 more source
Static recrystallization of shocked calcite in Ries impact breccias
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
Microspherules Formed by Lightning Strikes
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley +1 more source
Microbial Endolithic Community at Meteor Crater
Abstract Postimpact recovery and evolution in response to climate changes produced a modern ecosystem at Meteor Crater dominated by a grassland and woodland of piñon and juniper, which has been used to evaluate floral and megafaunal consequences of impact cratering during the Phanerozoic Eon of complex life.
David A. Kring, Charles S. Cockell
wiley +1 more source

