Triggers of widespread anoxia in the Western Interior Seaway during Oceanic Anoxic Event 2
AbstractAnthropogenic activity has affected the world’s oceans in various ways, causing warming, acidification and deoxygenation. Mechanisms driving and maintaining the latter can be understood by studying similar changes that occurred in the Earth’s past. This palynological study of Mid-Cretaceous (~94Ma) sediments from northern Canada sheds light on the drivers of anoxia and its development at higher latitudes. Changes in the palynological assemblages indicate that increased density stratification, through enhanced freshwater input and precipitation, were presumably the most important drivers. Changes in sea-level may have enhanced or counteracted the effects of stratification.
Stramma, L., Prince, E. D., Schmidtko, S., Luo, J., Hoolihan, J. P., Visbeck, M., … Körtzinger, A. (2011). Expansion of oxygen minimum zones may reduce available habitat for tropical pelagic fishes. Nature Climate Change, 2(1), 33–37. doi:10.1038/nclimate1304
Schlanger, S. O., & Jenkyns, H. C. (1976). Cretaceous oceanic anoxic events: causes and consequences. Geologie en mijnbouw, 55(3-4), 179-184.
Meyers, S. R., Sageman, B. B., & Arthur, M. A. (2012). Obliquity forcing of organic matter accumulation during Oceanic Anoxic Event 2. Paleoceanography, 27(3).
Jenkyns, H. C. (2010). Geochemistry of oceanic anoxic events. Geochemistry, Geophysics, Geosystems, 11(3), n/a–n/a. http://doi.org/10.1029/2009GC002788
Schröder-Adams, C. (2014). The Cretaceous Polar and Western Interior seas: paleoenvironmental history and paleoceanographic linkages. Sedimentary Geology, 301, 26–40. doi:10.1016/j.sedgeo.2013.12.003
Caballero-Alfonso, A. M., Carstensen, J., & Conley, D. J. (2014). Biogeochemical and environmental drivers of coastal hypoxia. Journal of Marine Systems. doi:10.1016/j.jmarsys.2014.04.008
Pearce, M. a., Jarvis, I., & Tocher, B. a. (2009). The Cenomanian–Turonian boundary event, OAE2 and palaeoenvironmental change in epicontinental seas: New insights from the dinocyst and geochemical records. Palaeogeography, Palaeoclimatology, Palaeoecology, 280(1-2), 207–234. doi:10.1016/j.palaeo.2009.06.012
Voigt, S., Gale, A. S., & Voigt, T. (2006). Sea-level change, carbon cycling and palaeoclimate during the Late Cenomanian of northwest Europe; an integrated palaeoenvironmental analysis. Cretaceous Research, 27(6), 836–858. doi:10.1016/j.cretres.2006.04.005
Arthur, M. A., Schlanger, S. T., & Jenkyns, H. C. (1987). The Cenomanian-Turonian Oceanic Anoxic Event, II. Palaeoceanographic controls on organic-matter production and preservation. Geological Society, London, Special Publications, 26(1), 401-420.
Corbett, M. J., & Watkins, D. K. (2013). Calcareous nannofossil paleoecology of the mid-Cretaceous Western Interior Seaway and evidence of oligotrophic surface waters during OAE2. Palaeogeography, Palaeoclimatology, Palaeoecology, 392, 510–523. doi:10.1016/j.palaeo.2013.10.007
Gale, A. S., & Christensen, W. K. (1996). Occurrence of the belemnite Actinocamax plenus in the Cenomanian of SE France and its significance. Bulletin of the Geological Society of Denmark, 43, 68-77.
Jarvis, I., Lignum, J. S., Gröcke, D. R., Jenkyns, H. C., & Pearce, M. a. (2011). Black shale deposition, atmospheric CO 2 drawdown, and cooling during the Cenomanian-Turonian Oceanic Anoxic Event. Paleoceanography, 26(3), n/a–n/a. doi:10.1029/2010PA002081
van Helmond, N. A., Sluijs, A., Reichart, G. J., Damsté, J. S. S., Slomp, C. P., & Brinkhuis, H. (2014). A perturbed hydrological cycle during Oceanic Anoxic Event 2. Geology, 42(2), 123-12
Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted under the conditions of the Creative Commons Attribution-Share Alike (CC BY-SA) license and that copies bear this notice and the full citation on the first page.