Impacts of fault-sill interactions on sill emplacement in the Vøring Basin, Norwegian North Sea

Siregar, Einstein; Omosanya, Kamaldeen Olakunle; Magee, Craig; Johansen, Ståle Emil

doi:10.1016/j.jsg.2019.06.006

Cited by 15 publications

(8 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Linear en-echelon dykes can indicate vertical/sub vertical magma transport, which may occur when laterally propagating magma interacts with faults (Mark et al 2019;Siregar et al 2019). Such dykes can be magma input points to source overlying sills (Mark et al 2019).…”

Section: Constraining Sill Emplacement Directionsmentioning

confidence: 99%

Emplacement of the Little Minch Sill Complex, Sea of Hebrides Basin, NW Scotland

Fyfe

Schofield

Holford

et al. 2021

JGS

View full text Add to dashboard Cite

The Little Minch Sill Complex is comprised of a series of stacked, multi-leaved Paleocene aged dolerite sills, which have been primarily intruded into Mesozoic sedimentary rocks and Paleocene tuffs/?hyaloclastites within the Sea of Hebrides Basin, situated on the NE Atlantic margin. Two previously proposed models for the emplacement of the sill complex have opposing ideas for the location of magma input and emplacement mechanisms. Both models have been constructed using data primarily from onshore outcrops, located on the Isle of Skye, Raasay and the Shiant Isles. However, onshore outcrops only represent a quarter (1040 km2) of the entire extent of the sill complex, which is largely situated offshore. In order to understand how the sill complex as a whole was emplaced within the basin, both onshore and offshore magma transport needs to be considered. Using high resolution multibeam bathymetry data (up to 2m resolution) obtained between 2008 and 2011 along with supporting seismic reflection, sparker and pinger data, a new assessment of the offshore extent and character of the sill complex has been constructed. Mapping of large-scale relationships between intrusions and the host rock, along with morphological features such as magma lobes, magma fingers, transgressive wings, en-echelon feeder dykes and the axis of saucer/half-saucer shaped intrusions, has indicated magma flow directions within the intrusive network. Assessing the flow kinematics of the sills has provided insights into magma transport and emplacement processes offshore. Combining data from previously mapped onshore sills with data from our newly constructed model for magma emplacement offshore has allowed us to construct a new model for the emplacement of the Little Minch Sill Complex. This model demonstrates that major basin bounding faults may play a lesser role in channelling magma through sedimentary basins than previously thought. Applying the knowledge obtained from this study could further progress understanding of the effect of sill emplacement on fluid flow within volcanic rift basin worldwide, with direct impacts on the exploitation of petroleum and geothermal systems.

show abstract

Section: Constraining Sill Emplacement Directionsmentioning

confidence: 99%

Emplacement of the Little Minch Sill Complex, Sea of Hebrides Basin, NW Scotland

Fyfe

Schofield

Holford

et al. 2021

JGS

View full text Add to dashboard Cite

show abstract

“…deformation, accommodated by folding above the western part of the sill and localised inversion of Fault 1 and overburden compaction above its eastern part (Figure 4D,6,and 9B) [Bédard et al 2012;Bunger and Cruden 2011;Galland and Scheibert 2013;Goulty and Schofield 2008;Magee et al 2017;Montanari et al 2017], and (iii) transgression of inclined sheets, which likely exploited fold-related outer-arc extensional fractures or fault opening of Fault 1, and perhaps fluid escape ( Figure 4D-F, 6, and 9C) [e.g. Bédard et al 2012;Magee et al 2013a;Siregar et al 2019;Thomson and Schofield 2008]. Subsequent burial-related compaction has modified the forced fold, by reducing its amplitude (F0 becomes F), but not the thickness of the incompressible sill ( Figure 9D) [e.g.…”

Section: Presses Universitaires De �Rasbourgmentioning

confidence: 99%

Fault inversion contributes to ground deformation above inflating igneous sills

et al. 2021

Self Cite

View full text Add to dashboard Cite

Magma emplacement is commonly accommodated by uplift of the overburden and free surface. By assuming this deformation is purely elastic, we can invert the shape and kinematics of ground deformation to model the geometry and dynamics of underlying intrusions. However, magma emplacement can be accommodated by viscoelastic and/or inelastic processes. We use 3D seismic reflection data to reconstruct how elastic bending and inelastic processes accommodated emplacement of a Late Jurassic sill offshore NW Australia. We restore syn-emplacement ground deformation and compare its relief to sill thickness, showing that: (i) where they are equal, elastic bending accommodated intrusion; but (ii) where sill thickness is greater, inversion of a pre-existing fault and overburden compaction contributed to magma accommodation. Our results support work showing inelastic processes can suppress ground deformation, and demonstrate magmatism can modify fault displacements. Reflection seismology is thus powerful tool for unravelling links between magma emplacement, ground deformation, and faulting.

show abstract

“…More so, intrusive rocks have a remarkable seismic stratigraphic expression on seismic profiles and are often characterised by local transgression across stratigraphic levels, restricted lateral continuity, and or/crosscutting relationship with the host-rock strata 83 . Intrusive rocks can also exploit conduits such as faults to migrate from deeper to shallow stratigraphic levels 84 .…”

Section: Methodsmentioning

confidence: 99%

Massive seafloor mounds depict potential for seafloor mineral deposits in the Great South Basin (GSB) offshore New Zealand

Omosanya

Lawal

Muhammad

et al. 2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

Seafloor mounds are enigmatic features along many continental margins and are often interpreted as gas hydrate pingoes, seep deposits, mud volcanoes, or hydrothermal mounds. When such mounds occur in basins with past volcanic activities, they have the potential to host seafloor metalliferous deposits, which is generally overlooked. Using geophysical datasets, we document the fluid plumbing systems that promoted the formation of seafloor mounds in the Great South Basin (GSB), offshore New Zealand. We also investigate these mounds as potential seafloor metalliferous deposits. Our results reveal 9 seafloor mounds (~ 137 m high) above gigantic (~ 5.4 km high) fluid escape pipes that are associated with deeper crystalline rocks. The structural make-up of the mounds, their geospatial relationships with the pipes and intrusive rocks, and geophysical properties suggest a primary volcanic or hydrothermal origin for the culpable fluids and mounds respectively. Fluids derived from deeper coal beds and shallow foraminiferal oozes in the basin constitute secondary fluid sources focused along polygonal faults and lateral flow cells. A main sub-vertical and minor lateral fluid plumbing patterns are proposed. The relationship between the mounds, pipes, underlying intrusive rocks, and upward routing of mineral-rich fluids could have implications for the formation of ore-grade mineral deposits on the seafloor in the GSB.

show abstract

Impacts of fault-sill interactions on sill emplacement in the Vøring Basin, Norwegian North Sea

Abstract: This is a repository copy of Impacts of fault-sill interactions on sill emplacement in the Vøring Basin, Norwegian North Sea.

Cited by 15 publications

References 55 publications

Emplacement of the Little Minch Sill Complex, Sea of Hebrides Basin, NW Scotland

Emplacement of the Little Minch Sill Complex, Sea of Hebrides Basin, NW Scotland

Fault inversion contributes to ground deformation above inflating igneous sills

Massive seafloor mounds depict potential for seafloor mineral deposits in the Great South Basin (GSB) offshore New Zealand

Contact Info

Product

Resources

About