Merlynd K. Nestell
Brooks B. Ellwood
Bruce R. Wardlaw
Asish R. Basu
Nilotpal Ghosh
Luu Thi Phuong Lan
Harry D. Rowe
Andrew G. Hunt
Jonathan H. Tomkin
Kenneth T. Ratcliffe
Galina P. Nestell
2015
<p><span>The </span><span>Permian</span><span>–</span><span>Triassic</span><span> mass extinction is postulated to be related to the rapid volcanism that produced the Siberian flood basalt (Traps). Unrelated volcanic eruptions producing several episodes of ash falls synchronous with the Siberian Traps are found in South China and Australia. Such regional eruptions could have caused wildfires, burning of coal deposits, and the dispersion of coal fly ash. These eruptions introduced a major </span><span>influx</span><span> of </span><span>carbon</span><span> into the atmosphere and </span><span>oceans</span><span> that can be recognized in the </span><span>wall</span><span>structure of foraminiferal tests present in survival populations in the boundary interval strata. Analysis of free specimens of </span><span>foraminifers</span><span> recovered from residues of conodont samples taken at a</span><span>Permian</span><span>–</span><span>Triassic</span><span> boundary section at Lung Cam in northern Vietnam has revealed the presence of a significant amount of elemental </span><span>carbon</span><span>, along with oxygen and silica, in their test </span><span>wall</span><span> structure, but an absence of calcium </span><span>carbonate</span><span>. These </span><span>foraminifers</span><span>, identified as </span><i>Rectocornuspira kalhori</i><span>, </span><i>Cornuspira mahajeri</i><span>, and </span><i>Earlandia</i><span> spp. and whose tests previously were considered to be calcareous, are confirmed to be </span><span>agglutinated</span><span>, and are now referred to as </span><i>Ammodiscus kalhori</i><span> and </span><i>Hyperammina deformis</i><span>. Measurement of the </span><sup>207</sup><span>Pb/</span><sup>204</sup><span>Pb ratios in pyrite clusters attached to the foraminiferal tests confirmed that these tests inherited the Pb in their outer layer from </span><span>carbon</span><span>-contaminated seawater. We conclude that the source of the </span><span>carbon</span><span> could have been either </span><span>global</span><span> coal fly ash or forest fire-dispersed </span><span>carbon</span><span>, or a combination of both, that was dispersed into the Palaeo-Tethys </span><span>Ocean</span><span> immediately after the end-</span><span>Permian</span><span> extinction event.</span></p>
application/pdf
10.1080/00206814.2015.1010610
en
Taylor & Francis
High influx of carbon in walls of agglutinated foraminifers during the Permian-Triassic transition in global oceans
article