Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’
Application of 3D-seismic reflection-data to igneous systems in sedimentary basins has led to a revolution in the understanding of mafic sill-complexes. However, there is considerable uncertainty on how geometries and architecture of sill complexes within the subsurface relates those imaged in seism...
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crescholarship:10.31223/osf.io/jfs9x 2024-04-07T07:52:10+00:00 Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ Eide, Christian Schofield, Nick Lecomte, Isabelle Buckley, Simon Howell, John 2017 http://dx.doi.org/10.31223/osf.io/jfs9x unknown California Digital Library (CDL) http://opensource.org/licenses/AFL-3.0 posted-content 2017 crescholarship https://doi.org/10.31223/osf.io/jfs9x 2024-03-08T03:58:03Z Application of 3D-seismic reflection-data to igneous systems in sedimentary basins has led to a revolution in the understanding of mafic sill-complexes. However, there is considerable uncertainty on how geometries and architecture of sill complexes within the subsurface relates those imaged in seismic reflection-data. To provide constraints on how sill complexes in seismic data should be interpreted, we present synthetic seismograms generated from a seismic-scale (22x0.25 km) outcrop in East Greenland constrained by abundant field-data.This study highlights how overlying igneous rocks adversely affect imaging of underlying intrusions and rocks by decreasing seismic amplitude, frequency and making steeply dipping features near-impossible to image. Furthermore, seismic modelling shows that because of the high impedance contrast between siliciclastic host rock and dolerites, thin (< 5m) intrusions should in principle be imaged at relatively high amplitudes. This is contrary to many published ‘rules of thumb’ for seismic detectability of sill intrusions. However, actual seismic data combined with well-data shows significant amounts of un-imaged sill intrusions, and this is likely due to limited resolution, overburden complexity, poor velocity-models, and interference between closely spaced sill-splays. Significant improvements could be made by better predicting occurrence and geometry of sill intrusions and including these in velocity models. Other/Unknown Material East Greenland Greenland eScholarship Repository (University of California) Greenland Thumb ENVELOPE(-64.259,-64.259,-65.247,-65.247) |
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eScholarship Repository (University of California) |
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Application of 3D-seismic reflection-data to igneous systems in sedimentary basins has led to a revolution in the understanding of mafic sill-complexes. However, there is considerable uncertainty on how geometries and architecture of sill complexes within the subsurface relates those imaged in seismic reflection-data. To provide constraints on how sill complexes in seismic data should be interpreted, we present synthetic seismograms generated from a seismic-scale (22x0.25 km) outcrop in East Greenland constrained by abundant field-data.This study highlights how overlying igneous rocks adversely affect imaging of underlying intrusions and rocks by decreasing seismic amplitude, frequency and making steeply dipping features near-impossible to image. Furthermore, seismic modelling shows that because of the high impedance contrast between siliciclastic host rock and dolerites, thin (< 5m) intrusions should in principle be imaged at relatively high amplitudes. This is contrary to many published ‘rules of thumb’ for seismic detectability of sill intrusions. However, actual seismic data combined with well-data shows significant amounts of un-imaged sill intrusions, and this is likely due to limited resolution, overburden complexity, poor velocity-models, and interference between closely spaced sill-splays. Significant improvements could be made by better predicting occurrence and geometry of sill intrusions and including these in velocity models. |
format |
Other/Unknown Material |
author |
Eide, Christian Schofield, Nick Lecomte, Isabelle Buckley, Simon Howell, John |
spellingShingle |
Eide, Christian Schofield, Nick Lecomte, Isabelle Buckley, Simon Howell, John Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
author_facet |
Eide, Christian Schofield, Nick Lecomte, Isabelle Buckley, Simon Howell, John |
author_sort |
Eide, Christian |
title |
Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
title_short |
Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
title_full |
Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
title_fullStr |
Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
title_full_unstemmed |
Seismic Interpretation of Sill-Complexes in Sedimentary Basins: The ‘Sub-Sill Imaging Problem’ |
title_sort |
seismic interpretation of sill-complexes in sedimentary basins: the ‘sub-sill imaging problem’ |
publisher |
California Digital Library (CDL) |
publishDate |
2017 |
url |
http://dx.doi.org/10.31223/osf.io/jfs9x |
long_lat |
ENVELOPE(-64.259,-64.259,-65.247,-65.247) |
geographic |
Greenland Thumb |
geographic_facet |
Greenland Thumb |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_rights |
http://opensource.org/licenses/AFL-3.0 |
op_doi |
https://doi.org/10.31223/osf.io/jfs9x |
_version_ |
1795667380396883968 |