Advanced

Linking the progressive expansion of reducing conditions to a stepwise mass extinction event in the late Silurian oceans

Bowman, Chelsie N.; Young, Seth A.; Kaljo, Dimitri; Eriksson, Mats E. LU ; Them, Theodore R.; Hints, Olle; Martma, Tõnu and Owens, Jeremy D. (2019) In Geology 47(10). p.968-972
Abstract

The late Ludlow Lau Event was a severe biotic crisis in the Silurian, characterized by resurgent microbial facies and faunal turnover rates otherwise only documented during the "big five" mass extinctions. This asynchronous late Silurian marine extinction event preceded an associated positive carbon isotope excursion (CIE), the Lau CIE, although a mechanism for this temporal offset remains poorly constrained. Here, we report thallium isotope data from locally reducing late Ludlow strata within the Baltic Basin to document the earliest onset of global marine deoxygenation. The initial expansion of anoxia coincided with the onset of the extinction and therefore preceded the Lau CIE. Additionally, sulfur isotope data record a large... (More)

The late Ludlow Lau Event was a severe biotic crisis in the Silurian, characterized by resurgent microbial facies and faunal turnover rates otherwise only documented during the "big five" mass extinctions. This asynchronous late Silurian marine extinction event preceded an associated positive carbon isotope excursion (CIE), the Lau CIE, although a mechanism for this temporal offset remains poorly constrained. Here, we report thallium isotope data from locally reducing late Ludlow strata within the Baltic Basin to document the earliest onset of global marine deoxygenation. The initial expansion of anoxia coincided with the onset of the extinction and therefore preceded the Lau CIE. Additionally, sulfur isotope data record a large positive excursion parallel to the Lau CIE, interpreted to indicate an increase in pyrite burial associated with the widely documented CIE. This suggests a possible global expansion of euxinia (anoxic and sulfidic water column) following deoxygenation. These data are the most direct proxy evidence of paleoredox conditions linking the known extinction to the Lau CIE through the progressive expansion of anoxia, and most likely euxinia, across portions of the late Silurian oceans.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Geology
volume
47
issue
10
pages
5 pages
publisher
Geological Society of America
external identifiers
  • scopus:85072696246
ISSN
0091-7613
DOI
10.1130/G46571.1
language
English
LU publication?
yes
id
8ae6261c-1415-4f67-850f-174f3de6e6ad
date added to LUP
2019-10-09 14:35:01
date last changed
2019-10-09 14:35:01
@article{8ae6261c-1415-4f67-850f-174f3de6e6ad,
  abstract     = {<p>The late Ludlow Lau Event was a severe biotic crisis in the Silurian, characterized by resurgent microbial facies and faunal turnover rates otherwise only documented during the "big five" mass extinctions. This asynchronous late Silurian marine extinction event preceded an associated positive carbon isotope excursion (CIE), the Lau CIE, although a mechanism for this temporal offset remains poorly constrained. Here, we report thallium isotope data from locally reducing late Ludlow strata within the Baltic Basin to document the earliest onset of global marine deoxygenation. The initial expansion of anoxia coincided with the onset of the extinction and therefore preceded the Lau CIE. Additionally, sulfur isotope data record a large positive excursion parallel to the Lau CIE, interpreted to indicate an increase in pyrite burial associated with the widely documented CIE. This suggests a possible global expansion of euxinia (anoxic and sulfidic water column) following deoxygenation. These data are the most direct proxy evidence of paleoredox conditions linking the known extinction to the Lau CIE through the progressive expansion of anoxia, and most likely euxinia, across portions of the late Silurian oceans.</p>},
  author       = {Bowman, Chelsie N. and Young, Seth A. and Kaljo, Dimitri and Eriksson, Mats E. and Them, Theodore R. and Hints, Olle and Martma, Tõnu and Owens, Jeremy D.},
  issn         = {0091-7613},
  language     = {eng},
  number       = {10},
  pages        = {968--972},
  publisher    = {Geological Society of America},
  series       = {Geology},
  title        = {Linking the progressive expansion of reducing conditions to a stepwise mass extinction event in the late Silurian oceans},
  url          = {http://dx.doi.org/10.1130/G46571.1},
  volume       = {47},
  year         = {2019},
}