Date and Time
Bath Royal Literary and Scientific Institution, 16-18 Queen Square, Bath BA1 2HN
The nature and causes of mass extinctions in the geological past have been intensely debated for the past three decades. Central to this debate are the questions of whether one or several bolide impacts, the eruption of Large Igneous Provinces (LIPs), or a combination of the two, were the primary mechanisms driving the environmental and habitat changes that are universally regarded as the proximate causes for four of the five major Phanerozoic mass extinction events.
Recent years have seen a revolution in our understanding of both the interplanetary environment and LIP eruptions and their environmental effects, such that the widely-accepted simple impact-kill scenario no longer seems adequate for the end-Cretaceous or any other mass extinction events. For example, single large impacts, (e.g., Chicxulub) as primary cause of mass extinctions have been questioned by planetary and space scientists because such impactors originating from the asteroid belt are random and rare.
In Earth sciences, critical advances have been made in radiometric age dating, which closely ties the Viluy, Siberian, Central Atlantic Magmatic Province (CAMP) and Deccan LIP volcanism to the end-Devonian, end-Permian, end-Triassic and end-Cretaceous mass extinctions, respectively. In India massively large volcanic pulses occurring in quick succession that may result in runaway greenhouse effects that could cause mass extinctions have been identified during a short time interval below the Cretaceous-Tertiary boundary. Also in India, the mass extinction in planktic foraminifera, which suffered near total extinctions at the end of the Cretaceous, has been documented in intertrappean sediments between these massive volcanic eruptions confirming the deadly nature of LIP volcanism.
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