Record details

Title
    Carbon isotope ("delta"13C) stratigraphy across the Silurian-Devonian transition in North America: evidence for a perturbation of the global carbon cycle
Statement of responsibility
    Matthew R. Saltzman
Author
    Saltzman, Matthew R.
Language
    anglicky
Source title - serial
    Palaeogeography, palaeoclimatology, palaeoecology
Vol./nr.
    Vol. 187, no. 1-2
Pages
    p. 83-100
Year
    2002
Notes
    8 obr., 3 tab., 3 s. bibl.
    il.
    Zkr. název ser.: Palaeogeogr. Palaeoclimatol. Palaeoecol.
Subject group
    Barrandien
    Conodonta
    cyklus uhlíkový
    devon
    Graptolithina
    izotopy C
    izotopy O
    izotopy stabilní
    pražská pánev
    sedimenty karbonátové
    silur
    stratigrafická hranice
    stratotyp
    zóny biostratigrafické
Geographical name
    ČR-Čechy
    Suchomasty (Beroun)
    USA
Keyword
    Across
    America
    Carbon
    Cycle
    Delta"13C
    Evidence
    Global
    Isotope
    North
    Perturbation
    Silurian-Devonian
    Stratigraphy
    Transition
Abstract (in english)
   arbon isotope (delta13C) analyses of marine carbonates spanning the Silurian-Devonian transition are compared from three richly fossiliferous, well-dated sequences in North America. The three sections, in the central Appalachian Mountains (West Virginia), Great Basin (Nevada), and the southern Mid-continent (Oklahoma), reveal positive delta13C shifts beginning in the late Pridoli and reaching peak values as heavy as +5.8promile in the earliest Lochkovian following the first occurrence of the conodont species Icriodus woschmidti and the graptolite Monograptus uniformis. A positive shift in delta13C is also recorded at this tune in Gondwanan regions, including the global stratotype section and point for the Silurian-Devonian boundary at Klonk in the Czech Republic, as well as in sections in the Carnic Alps of Austria (Cellon), and Queensland, Australia.
   The available data from Euramerica and Gondwana are consistent with a scenario linking seawater delta13C enrichment to a eustatic drop during the Silurian-Devonian transition. Seawater delta13C likely increased as a result of enhanced carbonate weathering during exposure and erosion of older Silurian platform deposits. In addition, the fall in sea level appears to have enhanced nutrient delivery to the oceans and triggered an increase in organic carbon burial rates at or near the Silurian-Devonian boundary, as indicated by organic-rich deposition in Gondwanan basins. In terms of its magnitude, the Silurian-Devonian delta13C excursion of = +5 promile appears to be among the largest well-documented events in the Paleozoic, comparable to the shifts in the Late Ordovician and Early Mississippian.
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    31. 3. 2008
Import date
    8. 8. 2012