Guadalupian Carbon Isotope Stratigraphy Indicates Extended Interval of Carbon Cycle Stability
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Guadalupian Carbon Isotope Stratigraphy Indicates Extended Interval of Carbon Cycle Stability. / Arefifard, Sakineh; Payne, Jonathan L.; Rizzi, Malgorzata.
I: American Journal of Science, Bind 322, Nr. 9, 2022, s. 1019-1046.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Guadalupian Carbon Isotope Stratigraphy Indicates Extended Interval of Carbon Cycle Stability
AU - Arefifard, Sakineh
AU - Payne, Jonathan L.
AU - Rizzi, Malgorzata
N1 - Publisher Copyright: © 2022 American Journal of Science. All rights reserved.
PY - 2022
Y1 - 2022
N2 - Stratigraphic variations in the carbon isotope composition of marine limestones (δ13Ccarb) have been widely reported from the Guadalupian, particularly in the uppermost Capitanian, but the extent to which they reflect global carbon cycle dynamics remains in dispute. Resolving these uncertainties is critical for interpreting the dynamics of the carbon cycle during the Guadalupian as well as for testing hypothesized circumstances of the marine extinction event during the Capitanian (latest Guadalupian). To assess the local versus global causes of stratigraphic variations in δ13Ccarb, here we report δ13Ccarb values from Guadalupian strata in the Hambast Valley, Abadeh region, southwest Iran, in two sections. We then compare the data from the two sections (Abadeh-1 and Abadeh-2) to data from numerous other wellstudied sections that were distant from central Iran at the time of deposition. In the Hambast sections, there are broad excursions of δ13Ccarb, of up to 3 . However, the δ13Ccarb values do not show any remarkable shifts across the Wordian/Capitanian or Capitanian/Wuchiapingian boundaries in the Abadeh-1 section. An excursion occurs near the Capitanian/Wuchiapingian boundary in the Abadeh-2 section but is associated with elemental and oxygen-isotope evidence for diagenetic resetting. The lack of reproducibility in the δ13Ccarb shifts between the two studied sections at Abadeh and evidence for diagenetic resetting in association with negative excursions are consistent with evidence from other, previously reported, study sites that negative excursions can be accounted for by local primary or diagenetic factors and do not require any global perturbation of the carbon cycle through this interval. When carbonate values are compared with previously published organic carbon isotope data and carbonate sections are compared for shared isotope features, the primary global signal that is supported by the data is one of stable and relatively heavy values of δ13Ccarb in marine limestone during the Guadalupian.
AB - Stratigraphic variations in the carbon isotope composition of marine limestones (δ13Ccarb) have been widely reported from the Guadalupian, particularly in the uppermost Capitanian, but the extent to which they reflect global carbon cycle dynamics remains in dispute. Resolving these uncertainties is critical for interpreting the dynamics of the carbon cycle during the Guadalupian as well as for testing hypothesized circumstances of the marine extinction event during the Capitanian (latest Guadalupian). To assess the local versus global causes of stratigraphic variations in δ13Ccarb, here we report δ13Ccarb values from Guadalupian strata in the Hambast Valley, Abadeh region, southwest Iran, in two sections. We then compare the data from the two sections (Abadeh-1 and Abadeh-2) to data from numerous other wellstudied sections that were distant from central Iran at the time of deposition. In the Hambast sections, there are broad excursions of δ13Ccarb, of up to 3 . However, the δ13Ccarb values do not show any remarkable shifts across the Wordian/Capitanian or Capitanian/Wuchiapingian boundaries in the Abadeh-1 section. An excursion occurs near the Capitanian/Wuchiapingian boundary in the Abadeh-2 section but is associated with elemental and oxygen-isotope evidence for diagenetic resetting. The lack of reproducibility in the δ13Ccarb shifts between the two studied sections at Abadeh and evidence for diagenetic resetting in association with negative excursions are consistent with evidence from other, previously reported, study sites that negative excursions can be accounted for by local primary or diagenetic factors and do not require any global perturbation of the carbon cycle through this interval. When carbonate values are compared with previously published organic carbon isotope data and carbonate sections are compared for shared isotope features, the primary global signal that is supported by the data is one of stable and relatively heavy values of δ13Ccarb in marine limestone during the Guadalupian.
KW - Abadeh
KW - Carbon isotopes
KW - Diagenetic alteration
KW - Global carbon cycle
KW - Guadalupian
U2 - 10.2475/09.2022.01
DO - 10.2475/09.2022.01
M3 - Journal article
AN - SCOPUS:85143168713
VL - 322
SP - 1019
EP - 1046
JO - American Journal of Science
JF - American Journal of Science
SN - 0002-9599
IS - 9
ER -
ID: 342929787