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Impact cratering is one of the most fundamental geological processes. On many planets, impact craters are the dominant geological landform. On Earth, erosion, plate tectonics, and volcanic resurfacing continually destroy the impact cratering record, but even here, the geological, biological, and environmental effects of impact cratering are apparent. Impact events are destructive and have been linked to at least one of the 'big five' mass extinctions over the past 540 million years. Intriguingly, impact craters can also have beneficial effects. Many impact craters are associated with economic metalliferous ore deposits and hydrocarbon reservoirs. This Special Paper from The Geological...

A fossil discovered in Montana has given new momentum to the hypothesis that dinosaurs were thriving right up until a devastating meteor hit Earth 65 million years ago, causing their extinction. Scientists from Yale University have found what is believed to be the youngest dinosaur fossil ever found, thought to be from just before the mass extinction took place. The discovery, described in a study published in the online edition of the journal Biology Letters, contradicts the theory that the dinosaurs slowly went extinct before the cosmic impact. The fossil -- a 45-centimetre horn believed to be from a triceratops...

"The previous data that we had ... actually said that they (the tektites and the ash) were different in age, that they differed by about 180,000 years and that the extinction happened before the impact, which would totally preclude there being a causal relationship," said Renne, who studies ties between mass extinctions and volcanism. He and colleagues were comparing a new technique to date geologic events when they realized there was a discrepancy in the timing -- the so-called 'K-T boundary' -- the geological span of time between the Cretaceous and Paleocene periods when the dinosaurs and most other life...

Catastrophic asteroid impacts are gaining a credible edge over violent volcanic eruptions as the greatest killers Earth has ever seen, according to two pieces of scientific detective work reported in tomorrow's issue of the journal Science. The first cataclysm in question occurred about 250 million years ago, when according to the fossil record more than 90 percent of Earth's marine species and 70 percent of life on land perished. The event is known as the Permian-Triassic (P-T for short) mass extinction, named because it falls on the boundary between the two geological eras. The second event, known as the Cretaceous-Tertiary...

The dinosaurs were wiped out 65 million years ago by at least two meteorite impacts, rather than a single strike, a new study suggests.Previously, scientists had identified a huge impact crater in the Gulf of Mexico as the event that spelled doom for the dinosaurs. Now evidence for a second impact in the Ukraine has been uncovered. This raises the possibility that the Earth may have been bombarded by a whole shower of meteorites. The new findings are published in the journal Geology by a team lead by Professor David Jolley of Aberdeen University. When first proposed in 1980, the...