Image_2_Provenance and Sediment Maturity as Controls on CO2 Mineral Sequestration Potential of the Gassum Formation in the Skagerrak.JPEG

• Main Authors: Mette Olivarius, Anja Sundal, Rikke Weibel, Ulrik Gregersen, Irfan Baig, Tonny B. Thomsen, Lars Kristensen, Helge Hellevang, Lars Henrik Nielsen
• Format: Still Image
• Language: unknown
• Published: 2019
• Subjects: Solid Earth Sciences; Climate Science; Atmospheric Sciences not elsewhere classified; Exploration Geochemistry; Inorganic Geochemistry; Isotope Geochemistry; Organic Geochemistry; Geochemistry not elsewhere classified; Igneous and Metamorphic Petrology; Ore Deposit Petrology; Palaeontology (incl. Palynology); Structural Geology; Tectonics; Volcanology; Geology not elsewhere classified; Seismology and Seismic Exploration; Glaciology; Hydrogeology; Natural Hazards; Quaternary Environments; Earth Sciences not elsewhere classified; Evolutionary Impacts of Climate Change; CO2 storage; reactive minerals; source to sink; zircon geochronology; depositional environments; petrography; diagenesis; reservoir quality; Fennoscandian
• Online Access: https://doi.org/10.3389/feart.2019.00312.s002; https://figshare.com/articles/Image_2_Provenance_and_Sediment_Maturity_as_Controls_on_CO2_Mineral_Sequestration_Potential_of_the_Gassum_Formation_in_the_Skagerrak_JPEG/11320562

In order to meet the increasing demand to decarbonize the atmosphere, storage of CO 2 in subsurface geological reservoirs is an effective measure. To maximize storage capacity, various types of saline aquifers should be considered including dynamic storage options with open or semi-open boundaries. In sloping aquifers, assessment of the immobilization potential for CO 2 through dissolution and mineralization along the flow path is a crucial part of risk evaluations. The Gassum Formation in the Skagerrak is considered a nearshore CO 2 storage option with sloping layers, facilitating buoyant migration of CO 2 northwards along depositional and structural dip. In this study, petrographic data and provenance analysis provide the basis for estimating reactivity of the sandstones. Immobilization of CO 2 in the reservoir through fluid dissolution and mineral reactions reduces risk of leakage. Petrographic analyses are integrated with seismic and well-log interpretation to identify sedimentary facies and to estimate mineral distribution with corresponding reactivity in the proposed injection area. Here the Gassum Formation comprises south-prograding, shoreface-fluvial para-sequences, sourced from northern hinterlands. Pronounced differences in the mineralogical maturity in the studied area are identified and explained by the sediment transport distances and the type of sediment source. This is possible because the U-Pb ages of zircon grains in the sediments can be used to pinpoint the areas where they originate from in the Fennoscandian Shield, such as the Telemarkia or Idefjorden terranes. Albite and Fe-rich chlorite are identified as the most reactive mineral phases in the Gassum sand, of which feldspar comprises the largest weight fraction and the grain-coating chlorite has largest surface area. Their distribution is partly controlled by provenance, so their abundance decreases basinwards with increasing sediment maturity. The abundance of fluvial sandstones presumably increases northwards in basal parts of ...