GEOL 766: Earth Systems Change

Discussion T3: Thursday, Oct. 16 and Tuesday, Oct. 21, 2008: Early Jurassic Toarcian oceanic anoxic event

A. Background and review

1. Cohen, A.S., Coe, A.L., and Kemp, D.B., 2007, The Late Palaeocene Early Eocene and Toarcian (Early Jurassic) carbon isotope excursions: a comparison of their time scales, associated environmental changes, causes and consequences: Journal of the Geological Society, London, v. 164, p. 1093-1108.
2. Jenkyns, H.C., 1988, The Early Toarcian (Jurassic) Anoxic Event - stratigraphic, sedimentary, and geochemical evidence: American Journal of Science, v. 288, p. 101-151.

B. Methane hydrate destabilization

3. Hesselbo, S.P., Grocke, D.R., Jenkyns, H.C., Bjerrum, C.J., Farrimond, P., Morgans Bell, H.S., and Green, O.R., 2000, Massive dissociation of gas hydrate during a Jurassic oceanic anoxic event: Nature, v. 406, p. 392-395.
4. Kemp, D.B., Coe, A.L., Cohen, A.S., and Schwark, L., 2005, Astronomical pacing of methane release in the Early Jurassic period: Nature, v. 437, p. 396-399.
5. Hesselbo, S.P., Jenkyns, H.C., Duarte, L.V., and Oliveira, L.C.V., 2007, Carbon-isotope record of the Early Jurassic (Toarcian) Oceanic Anoxic Event from fossil wood and marine carbonate (Lusitanian Basin, Portugal): Earth and Planetary Science Letters, v. 253, p. 455-470.

C. Questioning the methane hypothesis

6. Wignall, P.B., McArthur, J.M., Little, C.T.S., and Hallam, A., 2006, Palaeoceanography: Methane release in the Early Jurassic period: Nature, v. 441, p. E5.

D. Hydrothermal venting and ATS for the duration of the OAE event

7. Svensen, H., Planke, S., Chevallier, L., Malthe-Sorenssen, A., Corfu, F., and Jamtveit, B., 2007, Hydrothermal venting of greenhouse gases triggering Early Jurassic global warming: Earth and Planetary Science Letters, v. 256, p. 554-566.
8. Suan, G., Pittet, B., Bour, I., Mattioli, E., Duarte, L.V., and Mailliot, S., 2008, Duration of the Early Toarcian carbon isotope excursion deduced from spectral analysis: Consequence for its possible causes: Earth and Planetary Science Letters, v. 267, p. 666-679.

E. Numerical modeling and anoxic indicators

9. Beerling, D.J., and Brentnall, S.J., 2007, Numerical evaluation of mechanisms driving Early Jurassic changes in global carbon cycling: Geology, v. 35, p. 247-250.
10. Belcher, C.M., and McElwain, J.C., 2008, Limits for Combustion in Low O2 Redefine Paleoatmospheric Predictions for the Mesozoic: Science, v. 321, p. 1197-1200.
11. Pearce, C.R., Cohen, A.S., Coe, A.L., and Burton, K.W., 2008, Molybdenum isotope evidence for global ocean anoxia coupled with perturbations to the carbon cycle during the Early Jurassic: Geology, v. 36, p. 231-234.