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Global perturbation of the marine calcium cycle during the Permian-Triassic transition

Silva-Tamayo, Juan Carlos; Lau, Kimberly V.; Jost, Adam B.; Payne, Jonathan L.; Wignall, Paul B.; Newton, Robert J.; Eisenhauer, Anton; Depaolo, Donald J.; Brown, Shaun and Maher, Kate, et al. (2018) In Bulletin of the Geological Society of America 130(7-8). p.1323-1338
Abstract
A negative shift in the calcium isotopic
composition of marine carbonate rocks
spanning the end-Permian extinction horizon
in South China has been used to argue
for an ocean acidification event coincident
with mass extinction. This interpretation
has proven controversial, both because the
excursion has not been demonstrated across
multiple, widely separated localities, and because
modeling results of coupled carbon and
calcium isotope records illustrate that calcium
cycle imbalances alone cannot account
for the full magnitude of the isotope excursion.
Here, we further test potential controls
on the Permian-Triassic calcium isotope
record by measuring calcium isotope... (More)
A negative shift in the calcium isotopic
composition of marine carbonate rocks
spanning the end-Permian extinction horizon
in South China has been used to argue
for an ocean acidification event coincident
with mass extinction. This interpretation
has proven controversial, both because the
excursion has not been demonstrated across
multiple, widely separated localities, and because
modeling results of coupled carbon and
calcium isotope records illustrate that calcium
cycle imbalances alone cannot account
for the full magnitude of the isotope excursion.
Here, we further test potential controls
on the Permian-Triassic calcium isotope
record by measuring calcium isotope ratios
from shallow-marine carbonate successions
spanning the Permian-Triassic boundary in
Turkey, Italy, and Oman. All measured sections
display negative shifts in δ44/40Ca of up
to 0.6‰. Consistency in the direction, magnitude,
and timing of the calcium isotope excursion
across these widely separated localities
implies a primary and global δ44/40Ca signature.
Based on the results of a coupled box
model of the geological carbon and calcium
cycles, we interpret the excursion to reflect a
series of consequences arising from volcanic
CO2 release, including a temporary decrease
in seawater δ44/40Ca due to short-lived ocean
acidification and a more protracted increase
in calcium isotope fractionation associated
with a shift toward more primary aragonite
in the sediment and, potentially, subsequently
elevated carbonate saturation states
caused by the persistence of elevated CO2
delivery from volcanism. Locally, changing
balances between aragonite and calcite production
are sufficient to account for the calcium
isotope excursions, but this effect alone
does not explain the globally observed negative
excursion in the δ13C values of carbonate
sediments and organic matter as well. Only
a carbon release event and related geochemical
consequences are consistent both with
calcium and carbon isotope data. The carbon
release scenario can also account for oxygen
isotope evidence for dramatic and protracted
global warming as well as paleontological
evidence
for the preferential extinction of
marine animals most susceptible to acidification,
warming, and anoxia. (Less)
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Bulletin of the Geological Society of America
volume
130
issue
7-8
pages
16 pages
publisher
Geological Society of America
external identifiers
  • scopus:85049218797
ISSN
0016-7606
DOI
10.1130/B31818.1
language
English
LU publication?
yes
id
6543017c-6a84-44b2-a897-83c36d0dfe34
alternative location
https://pubs.geoscienceworld.org/gsa/gsabulletin/article/527060/Global-perturbation-of-the-marine-calcium-cycle
date added to LUP
2018-05-02 16:45:20
date last changed
2018-08-26 05:03:22
@article{6543017c-6a84-44b2-a897-83c36d0dfe34,
  abstract     = {A negative shift in the calcium isotopic<br/>composition of marine carbonate rocks<br/>spanning the end-Permian extinction horizon<br/>in South China has been used to argue<br/>for an ocean acidification event coincident<br/>with mass extinction. This interpretation<br/>has proven controversial, both because the<br/>excursion has not been demonstrated across<br/>multiple, widely separated localities, and because<br/>modeling results of coupled carbon and<br/>calcium isotope records illustrate that calcium<br/>cycle imbalances alone cannot account<br/>for the full magnitude of the isotope excursion.<br/>Here, we further test potential controls<br/>on the Permian-Triassic calcium isotope<br/>record by measuring calcium isotope ratios<br/>from shallow-marine carbonate successions<br/>spanning the Permian-Triassic boundary in<br/>Turkey, Italy, and Oman. All measured sections<br/>display negative shifts in δ44/40Ca of up<br/>to 0.6‰. Consistency in the direction, magnitude,<br/>and timing of the calcium isotope excursion<br/>across these widely separated localities<br/>implies a primary and global δ44/40Ca signature.<br/>Based on the results of a coupled box<br/>model of the geological carbon and calcium<br/>cycles, we interpret the excursion to reflect a<br/>series of consequences arising from volcanic<br/>CO2 release, including a temporary decrease<br/>in seawater δ44/40Ca due to short-lived ocean<br/>acidification and a more protracted increase<br/>in calcium isotope fractionation associated<br/>with a shift toward more primary aragonite<br/>in the sediment and, potentially, subsequently<br/>elevated carbonate saturation states<br/>caused by the persistence of elevated CO2<br/>delivery from volcanism. Locally, changing<br/>balances between aragonite and calcite production<br/>are sufficient to account for the calcium<br/>isotope excursions, but this effect alone<br/>does not explain the globally observed negative<br/>excursion in the δ13C values of carbonate<br/>sediments and organic matter as well. Only<br/>a carbon release event and related geochemical<br/>consequences are consistent both with<br/>calcium and carbon isotope data. The carbon<br/>release scenario can also account for oxygen<br/>isotope evidence for dramatic and protracted<br/>global warming as well as paleontological<br/>evidence<br/>for the preferential extinction of<br/>marine animals most susceptible to acidification,<br/>warming, and anoxia.},
  author       = {Silva-Tamayo, Juan Carlos and Lau, Kimberly V. and Jost, Adam B. and Payne, Jonathan L. and Wignall, Paul B. and Newton, Robert J. and Eisenhauer, Anton and Depaolo, Donald J. and Brown, Shaun and Maher, Kate and Lehrmann, Daniel J. and Altiner, Demir and Yu, Meiyi and Richoz, Sylvain and Paytan, Adina},
  issn         = {0016-7606},
  language     = {eng},
  month        = {01},
  number       = {7-8},
  pages        = {1323--1338},
  publisher    = {Geological Society of America},
  series       = {Bulletin of the Geological Society of America},
  title        = {Global perturbation of the marine calcium cycle during the Permian-Triassic transition},
  url          = {http://dx.doi.org/10.1130/B31818.1},
  volume       = {130},
  year         = {2018},
}