Introduction: In simple impact craters like Barringer Meteorite Crater (aka Meteor Crater), very little molten material was generated. There are no detectable melt ponds within the breccia lens or any significant melt pools on the crater walls or in the ejecta blanket. There was either an insufficient volume of melt produced by the impact event and/or it was too finely disseminated, possibly be...

Introduction: Small impact events resulting in simple impact structures <100 m in diameter are common features recorded on the solid surfaces in our Solar System. Such structures are rare in Earth's impact cratering record and most are typically heavily modified by subsequent erosion or are found in remote locations. The recently discovered Whitecourt Meteorite Impact Crater (WMIC) provides sig...

Volcanic crater lakes are isolated habitats that are particularly well suited to investigating ecological and evolutionary divergence and modes of speciation. However, the mode, frequency, and timing of colonization of crater lakes have been difficult to determine. We used a statistical comparative phylogeographic approach, based on a mitochondrialDNA dataset, to infer the colonization history ...

Introduction: The Kara River basin, located between the Pai-Khoi ridge and the Baydarata Gulf of the Kara Sea 200 km to the north of Vorkuta, Russia, was found to be an impact structure in 1970’s [1,2]. The 40Ar-39Ar impactite ages vary from 70 to 75 Ma [3,4]. Actually, two craters were suggested [1]: The Kara crater, 60-65 km in diameter, was defined on the Kara River estuary while the 25 km U...

Introduction: The Catalog of Large Martian Impact Craters [1] was compiled from Viking 1:2M photomosaics around 1980 and contains information on 42,283 craters generally ≥5-km-diameter across the entire Martian surface. The Catalog is undergoing revision using MGS (MOLA) and Odyssey (THEMIS) data. We have completed the initial revision of northern hemisphere craters, updating latitude and longi...

[1] The density of impact craters calibrated against lunar data is currently the only quantitative measure of surface age for terrestrial planetary surfaces. Unlike the Moon, however, Mars has been weathered and eroded, obliterating some small (<10 km diameter) craters, a phenomenon addressed in the Mariner/Viking days of Mars exploration but commonly overlooked in recent studies. We present a ...

Small-crater counts on Mars light-toned sedimentary rock are often inconsistent with any isochron; these data are usually plotted then ignored. We show (using an 18-HiRISE-image, > 10 4 -crater dataset) that these non-isochron crater counts are often well-fit by a model where crater production is balanced by crater obliteration via steady exhumation. For these regions, we fit erosion rates. We ...