Spatio-temporal volcanic evolution and CO2 storage potential of the mid-Norwegian volcanic rifted margin

This research proposal links to the International Ocean Discovery Program (IODP) Expedition 396 which will drill several scientific research boreholes along the offshore Norwegian continental margin. The Norwegian margin is one of the best studied examples of a passive rifted margin associated with voluminous magmatic activity. However, key scientific questions associated with the origins of magmatism and its impacts on global climate at this time remain. The objectives of the cruise cover a wide range of high impact scientific research areas including assessing the role of the Iceland plume on excess magmatism, understanding along axis variations in magmatism, determining the nature and depositional environment of volcanism, and assessing the role that magmatism played in driving global warming (Paleocene Eocene Thermal Maximum or PETM) at this time. A secondary goal of the expedition is to appraise the potential of permanent carbon capture and storage (CCS) in the volcanic sequences. This research project will address several of the EXP 396 objectives focusing on three specific areas of research.
Objective 1: Understanding the interplay between magmatism and eruption environments during rifting.
Volcanic cores will be used to appraise how volcanism and the environment of eruption changed in space and time during continental rifting. Detailed facies analyses of the volcanic sequences will be undertaken to reveal whether the eruptions occurred within subaerial, marginal, or subaqueous environments. Geophysical logging data will be used alongside core observations to build a comprehensive and integrated volcanological model for the borehole penetrated sequences. The geophysical volcanic model will then be used to calibrate extensive 3D seismic surveys in the area which in turn will enable mapping of volcanic facies over large parts of the margin. This aspect of the project will enable new understanding about how extrusive magmatism is linked to margin scale base-level changes which in turn will give new data for testing competing models for volcanic rifted margin evolution such as plume-pulsing versus plate tectonics.
Objective 2: Appraising the carbon capture and storage (CCS) potential of break-up related volcanic sequences.
Pilot studies on Iceland (Carbfix) and in Washington State, USA (Wallula), have demonstrated that CO2 reacts with basaltic rocks to form carbonate minerals, effectively permanently storing the CO2. Permanent storage clearly reduces the risk of leakage and has been demonstrated to occur over incredibly rapid timescales on the order of a few years. The huge volume of offshore break-up related volcanic sequences that will be tested during EXP. 396 could offer an alternative storage site for permanent storage of anthropogenic CO2. Volcanic sequences can have good reservoir properties, however, extensive weathering and alteration can also significantly diminish and clog up the pore structure. Within this study petrophysical analyses of volcanic cores will be performed to give important new constraints on the reservoir potential and sealing capacity of the Atlantic margin volcanic sequences.
Objective 3: Understanding the temporal and spatial evolution of magma petrogenesis within the province and its potential role in driving the PETM.
Geochemical analyses from the various volcanic sequences will be used to appraise whether elevated and/or fluctuating mantle temperatures led to excess magmatism in mid-Norway. Regional datasets will be compared to appraise how melting changed along the margin and whether these results resolve competing plume or plate tectonic models. Some sites will target hydrothermal vents associated with break-up related intrusions which caused massive emissions of Greenhouse gases. High resolution core-log-seismic appraisal coupled with isotopic dating of the ejecta layers will hopefully improve the age constraints on these processes in order to better appraise links to the PETM.