Contributed by Kea Giles, Managing Editor, Geology
Boulder, Colo., USA: Mass extinctions are extremely catastrophic events on Earth. Throughout Earth's evolutionary history, numerous mass extinctions have occurred, with five major mass extinctions being particularly representative. These extinctions have reshaped the course of life's evolution on Earth. In addition to the five major mass extinctions, many frequent, lower-order extinctions have also taken place on Earth, such as the Norian–Rhaetian Extinction during the Triassic. Regarding the triggering mechanisms of extinctions, the five major events have been relatively well studied. However, the triggering mechanisms of the frequent lower-order extinctions remain unclear.
In their new study titled " Marine large igneous provinces: Key drivers of Triassic recurrent extinction " and published last week in Geology, Jian-Jun Fan and colleagues present a detailed analysis of oceanic island, seamount, and plateau remnants in the Tibetan Plateau that trace the evolution of Meso- and Neo-Tethys, incorporating new and published data. During the Triassic, three major episodes of marine large igneous provinces (LIPs) formed at 250–248, 233–231, and 210–208 million years ago. By integrating geological records of these LIP episodes with Triassic geological datasets, Fan and colleagues demonstrate a correlation between marine LIPs and at least four extinctions in marine biota, driven by the resultant anoxic-euxinic events. Marine LIPs account for half of the extinctions with an identifiable geological trigger during the Triassic. This indicates that marine LIPs are a key driver of Triassic extinctions.
Marine LIP eruptions on Earth are frequent; however, evidence of ancient marine LIPs is likely significantly reduced by subduction during ocean basin closure. The authors note that "this destruction renders such records difficult to identify and, even when identified, challenging to interpret and date precisely," and therefore hypothesize that orogenic belts (i.e., remnants of vanished ancient ocean basins) contain many unidentified "ghost" marine LIPs, and these marine LIP eruptions likely constitute a key driver of other Phanerozoic extinctions that were previously under-recognized in Earth system models.
Geology: https://doi.org/10.1130/G53406.1
About the Geological Society of America
The Geological Society of America (GSA) is a global professional society with more than 17,000 members across over 100 countries. As a leading voice for the geosciences, GSA advances the understanding of Earth's dynamic processes and fosters collaboration among scientists, educators, and policymakers. GSA publishes Geology, the top-ranked geoscience journal, along with a diverse portfolio of scholarly journals, books, and conference proceedings—several of which rank among Amazon's top 100 best-selling geology titles.
