Web: https://fallmeeting.agu.org/2016/
Includes the following sessions:
V018. Mass extinction events: from above or below
Convenors: Michael Rampino (mrr1@nyu.edu), Ken Caldeira (kcaldeira@standford.edu)
Two kinds of catastrophic events—large-body impact and flood-basalt volcanism—have been suggested as the cause of mass extinctions. It has also been proposed that these events show periodic patterns. Flood basalt eruptions have been further linked to Oceanic Anoxic Events, as a proximate cause of the extinctions. In this session, we will explore these potential connections. The subject of the session is very topical, as mass extinctions, flood basalts and impacts are all “hot button” issues. Correlation among them would suggest that extreme physical changes in the environment are required to produce extinctions. We would pursue abstracts that address the nature of these correlations and patterns, as well as studies on the environmental effects of impacts and flood basalts.
V024. Quaternary and Neogene hotspot volcanism on the Cretaceous Kerguelen Plateau, Southern Indian Ocean: nature and potential environmental impact
Convenors: Millard Coffin (mike.coffin@utas.edu.au), Robert Duncan (rduncan@coas.oregonstate.edu)
The Kerguelen Plateau, a large igneous province (LIP) of predominantly Cretaceous age in the southern Indian Ocean, has experienced widespread Quaternary and Neogene hotspot volcanism. Loci of this younger magmatism include not only the Kerguelen Isles, Heard Island, the McDonald Islands, and the seafloor surrounding these islands, but also broad areas elsewhere on the Central Kerguelen Plateau. Recent data and samples acquired from the seafloor, islands, and water column are illuminating the origin, age, and distribution of the Quaternary and Neogene hotspot volcanism as well as its role in supplying iron to the anemic Southern Ocean. Phytoplankton, which produce approximately half of the oxygen in the Earth’s atmosphere, require iron to metabolize and bloom. This multidisciplinary session aims to foster better understanding of young hotspot volcanism in the Southern Ocean and its potential role in supplying iron to surface waters where it nourishes phytoplankton.
V028. The ins and outs of flood basalts
Convenors: Wendy Bohrson (bohrson@geology.cwu.edu), Anita Grunder (grundera@geo.oregonstate.edu)
Flood Basalts are catastrophic, voluminous magmatic events that punctuate Earth History. We invite papers that address a range of questions that contribute to an integrated view of flood basalt magmatism from eruption dynamics to mantle source characteristics. What volcanic processes distinguish flood basalts? How do the erupted products change with time, and what is the character of the feeder systems? What is the duration of magmatism? What is the role of crustal modulation, including the location and size of magma reservoirs? What is the balance between crustal (e.g., assimilation, crystal accumulation) and mantle input, and does this balance change with time? What mantle sources are involved, and what distinguishing characteristics allow these source contributions to be resolved? Studies that document the petrological, geochemical, geochronological, volcanological and geophysical attributes of flood basalts and associated crust and mantle are encouraged, to ultimately assemble a temporal and spatial synthesis of these extraordinary events.