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Dinosaur rise linked to end-Triassic methane carbon release?



From: Ben Creisler
bh480@scn.org

In the new issue of Science:

News story:
Did Greenhouse Gasses Unleash the Dinosaurs?
http://news.sciencemag.org/sciencenow/2011/07/did-greenhouse-gasses-unleash-
th.html?ref=hp

The paper:

Micha Ruhl, Nina R. Bonis, Gert-Jan Reichart, Jaap S. Sinninghe Damsté, &
Wolfram M. Kürschner (2011)
Atmospheric Carbon Injection Linked to End-Triassic Mass Extinction.
Science 333(6041): 430-434  (22 July 2011): 
DOI: 10.1126/science.1204255 
http://www.sciencemag.org/content/333/6041/430.abstract

Abstract
The end-Triassic mass extinction (~201.4 million years ago), marked by
terrestrial ecosystem turnover and up to ~50% loss in marine biodiversity,
has been attributed to intensified volcanic activity during the break-up of
Pangaea. Here, we present compound-specific carbon-isotope data of
long-chain n-alkanes derived from waxes of land plants, showing a ~8.5 per
mil negative excursion, coincident with the extinction interval. These data
indicate strong carbon-13 depletion of the end-Triassic atmosphere, within
only 10,000 to 20,000 years. The magnitude and rate of this carbon-cycle
disruption can be explained by the injection of at least ~12 × 103 gigatons
of isotopically depleted carbon as methane into the atmosphere. Concurrent
vegetation changes reflect strong warming and an enhanced hydrological
cycle. Hence, end-Triassic events are robustly linked to methane-derived
massive carbon release and associated climate change. 


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