Enhanced Cenozoic chemical weathering and the subduction of pelagic carbonate
@article{Caldeira1992EnhancedCC, title={Enhanced Cenozoic chemical weathering and the subduction of pelagic carbonate}, author={Ken Caldeira}, journal={Nature}, year={1992}, volume={357}, pages={578-581} }
THE observed trend of increasing oceanic 87Sr/86Sr ratios during the late Cenozoic led Raymo et al.1 to propose that chemical weathering rates increased at this time as a result of enhanced weatherability of silicate rocks. They suggested that this was due in turn to continential uplift, primarily in the Himalayas and the Andes. Because weathering involves the reaction of silicates with atmospheric carbon dioxide, considerations of changes in weathering rates must take into account the need to…
64 Citations
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References
SHOWING 1-10 OF 29 REFERENCES
Influence of late Cenozoic mountain building on ocean geochemical cycles
- Environmental Science, Geography
- 1988
In a steady-state ocean, input fluxes of dissolved salts to the sea must be balanced in mass and isotopic value by output fluxes. For the elements strontium, calcium, and carbon, rivers provide the…
Modelling the Phanerozoic carbon cycle and climate: constraints from the 87Sr/86Sr isotopic ratio of seawater.
- Environmental Science, GeographyAmerican journal of science
- 1992
A history of atmospheric carbon dioxide and climate during Phanerozoic time, consistent with the strontium isotopic data, is reconstructed and is shown to be compatible with paleoclimatic indicators, such as the timing of glaciation and the estimates of Cretaceous paleotemperatures.
Tertiary paleoceanic chemical variability: Unintended consequences of simple geochemical models
- Environmental Science, Geology
- 1988
Five lines of concrete, quantitative evidence about oceanic chemical composition during the past 65 m.y. can provide insights into the controlling processes and their temporal variations, but the…
Rise of angiosperms as a factor in long-term climatic cooling
- Environmental Science, Geology
- 1989
By Late Cretaceous or early Tertiary time, the diversification and proliferation of angiosperm-deciduous ecosystems resulted in higher rates of mineral weathering. This increase in the global average…
Steady- and non-steady-state carbonate-silicate controls on atmospheric CO2
- Environmental Science
- 1991
The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years
- Environmental Science, Geology
- 1983
A computer model has been constructed that considers the effects on the CO/sub 2/ level of the atmosphere, and the Ca, Mg, and HCO/sub 3/ levels of the ocean, of the following processes: weathering…
Continental-pelagic carbonate partitioning and the global carbonate-silicate cycle.
- Environmental Science, GeologyGeology
- 1991
Model results suggest that carbonate deposition patterns established during the Cenozoic may be pushing the Earth system from the continental to the pelagic mode on a time scale of 10(8) yr, with a possible consequent order-of-magnitude increase in the metamorphic CO2 flux to the atmosphere.
Variation of seawater 87Sr/86Sr throughout Phanerozoic time
- Geology, Geography
- 1982
Precise measurements of 786 marine carbonate, evaporite, and phosphate samples of known age provide a curve of seawater 87Sr/86Sr versus geologic time through the Phanerozoic. Many episodes of…
Late Cenozoic Ge/Si record of marine biogenic opal: Implications for variations of riverine fluxes to the ocean
- Environmental Science, Geography
- 1989
We have determined germanium/silicon ratios in purified diatoms and radiolarians from siliceous sediments in Holocene core tops, one late Pleistocene piston core, and four high-latitude Southern…