Interpreting carbon-isotope excursions: Stranglove oceans

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1991)019<0299:ICIESO>2.3.CO;2· OSTI ID:5657241

Kump, L R ^[1]

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1. Pennsylvania State Univ., University Park (USA)

Large negative excursions in marine carbonate {delta}{sup 13}C are commonly associated with period boundaries and mass extinctions. Explanations for these events must be consistent with limitations imposed by carbon-isotope mass balance. At steady state (i.e., for excursions lasting more than 10{sup 5} yr), the surface ocean {delta}{sup 13}C is set by the organic fraction of the total carbon burial rate and the magnitude of the photosynthetic isotope effect. The {delta}{sup 13}C of the deep ocean and the surface-to-deep isotope gradient are set by both the organic fraction of the ocean's remineralized particulate flux and the magnitude of the isotope effect. Thus it is the carbon-isotope composition of the deep ocean that is most reflective of internal oceanic processes; the surface ocean records changes in the longer term throughput of carbon in the system. The cessation of organic export from the surface ocean, such as is presumed to have caused the Strangelove ocean condition of the Cretaceous/Tertiary (K/T) boundary, leads to an isotopically homogeneous ocean in decades to centuries. If this condition persists, the ocean's isotopic composition approaches that of the riverine weathering input (in 10{sup 5} yr). Failure to approach this value during the K/T event suggests continued production and burial of organic carbon, dominantly in either terrestrial or shallow-marine environments.

• OSTI ID: 5657241
• Journal Information: Geology; (USA), Journal Name: Geology; (USA) Vol. 19:4; ISSN GLGYB; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
BOUNDARY CONDITIONS
BOX MODELS
CARBON 13
CARBON CYCLE
CARBON ISOTOPES
CENOZOIC ERA
CRETACEOUS PERIOD
DEATH
DEPOSITION
DEPTH
DIMENSIONS
EVEN-ODD NUCLEI
GEOLOGIC AGES
GEOLOGIC HISTORY
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MASS BALANCE
MASS TRANSFER
MATHEMATICAL MODELS
MATTER
MESOZOIC ERA
NUCLEI
ORGANIC MATTER
SEAS
STABLE ISOTOPES
SURFACE WATERS
TERTIARY PERIOD
VARIATIONS
WEATHERING