Inversion and exhumation of the St. George's Channel basin offshore Wales UK
The western UK basins of the Irish Sea have provided one of the best natural laboratories for investigating the causes and consequences of intracratonic uplift and erosion (exhumation). To date, the emphasis has been on igneous underplating as the chief process driving their exhumation. In this pape...
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/46941 2023-12-24T10:23:22+01:00 Inversion and exhumation of the St. George's Channel basin offshore Wales UK Williams, G. Turner, J. Holford, S. 2005 http://hdl.handle.net/2440/46941 https://doi.org/10.1144/0016-764904-023 en eng Geological Soc Publ House Journal of the Geological Society, 2005; 162(1):97-110 0016-7649 2041-479X http://hdl.handle.net/2440/46941 doi:10.1144/0016-764904-023 Holford, S. [0000-0002-4524-8822] http://dx.doi.org/10.1144/0016-764904-023 phosphates Paleogene Cenozoic Tertiary upper Tertiary Phanerozoic Mesozoic Cretaceous Atlantic Ocean North Atlantic Europe Western Europe United Kingdom Great Britain heat flow geothermal gradient reflectance vitrinite fission tracks apatite thermal history gravity anomalies transtension transpression Eocene Neogene Upper Cretaceous faults reactivation inversion tectonics underplating erosion uplifts vertical seismic profiles free-air anomalies exhumation inverse problem tectonic controls seismic methods Irish Sea Wales Journal article 2005 ftunivadelaidedl https://doi.org/10.1144/0016-764904-023 2023-11-27T23:19:22Z The western UK basins of the Irish Sea have provided one of the best natural laboratories for investigating the causes and consequences of intracratonic uplift and erosion (exhumation). To date, the emphasis has been on igneous underplating as the chief process driving their exhumation. In this paper, we demonstrate that tectonic inversion (the shortening of formerly extensional basins and reactivation of their constituent faults) dominated the exhumation of the St. George's Channel basin, offshore Wales. Based on mapping of an extensive 2D seismic grid, evidence is presented for at least two major inversion episodes in the Late Cretaceous and the Neogene, plus minor shortening during the Eocene. Inversion was distinctly noncoaxial, especially during the Neogene when coeval transpression and transtension was focused at discrete bends and stepovers on the basin-bounding St. George's, Bala and Northwest Flank faults. That the principal mechanism driving these uplift episodes was inversion (as opposed to igneous underplating) is corroborated by analysis of thermal history data (apatite fission track and vitrinite reflectance). They reveal late Cretaceous and Neogene geothermal gradients that were comparable with that at the present day, i.e. no significant increase in basal heat flow. Sonic velocity profiles logged in hydrocarbon boreholes constrain the minimum thickness of the eroded section, which varies between c. 1000 m in the centre and c. 2240 m at the margins of the basin. Given the strength of evidence for tectonic inversion in the St. George's Channel basin, our favoured model invokes superimposition of the effects of inversion and igneous underplating to account for the complex exhumation history of the St. George's Channel basin in particular, and the western UK basins in general. Williams Gareth A., Turner Jonathan P. and Holford Simon P. Article in Journal/Newspaper North Atlantic The University of Adelaide: Digital Library Bala ENVELOPE(132.817,132.817,67.178,67.178) Journal of the Geological Society 162 1 97 110 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
topic |
phosphates Paleogene Cenozoic Tertiary upper Tertiary Phanerozoic Mesozoic Cretaceous Atlantic Ocean North Atlantic Europe Western Europe United Kingdom Great Britain heat flow geothermal gradient reflectance vitrinite fission tracks apatite thermal history gravity anomalies transtension transpression Eocene Neogene Upper Cretaceous faults reactivation inversion tectonics underplating erosion uplifts vertical seismic profiles free-air anomalies exhumation inverse problem tectonic controls seismic methods Irish Sea Wales |
spellingShingle |
phosphates Paleogene Cenozoic Tertiary upper Tertiary Phanerozoic Mesozoic Cretaceous Atlantic Ocean North Atlantic Europe Western Europe United Kingdom Great Britain heat flow geothermal gradient reflectance vitrinite fission tracks apatite thermal history gravity anomalies transtension transpression Eocene Neogene Upper Cretaceous faults reactivation inversion tectonics underplating erosion uplifts vertical seismic profiles free-air anomalies exhumation inverse problem tectonic controls seismic methods Irish Sea Wales Williams, G. Turner, J. Holford, S. Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
topic_facet |
phosphates Paleogene Cenozoic Tertiary upper Tertiary Phanerozoic Mesozoic Cretaceous Atlantic Ocean North Atlantic Europe Western Europe United Kingdom Great Britain heat flow geothermal gradient reflectance vitrinite fission tracks apatite thermal history gravity anomalies transtension transpression Eocene Neogene Upper Cretaceous faults reactivation inversion tectonics underplating erosion uplifts vertical seismic profiles free-air anomalies exhumation inverse problem tectonic controls seismic methods Irish Sea Wales |
description |
The western UK basins of the Irish Sea have provided one of the best natural laboratories for investigating the causes and consequences of intracratonic uplift and erosion (exhumation). To date, the emphasis has been on igneous underplating as the chief process driving their exhumation. In this paper, we demonstrate that tectonic inversion (the shortening of formerly extensional basins and reactivation of their constituent faults) dominated the exhumation of the St. George's Channel basin, offshore Wales. Based on mapping of an extensive 2D seismic grid, evidence is presented for at least two major inversion episodes in the Late Cretaceous and the Neogene, plus minor shortening during the Eocene. Inversion was distinctly noncoaxial, especially during the Neogene when coeval transpression and transtension was focused at discrete bends and stepovers on the basin-bounding St. George's, Bala and Northwest Flank faults. That the principal mechanism driving these uplift episodes was inversion (as opposed to igneous underplating) is corroborated by analysis of thermal history data (apatite fission track and vitrinite reflectance). They reveal late Cretaceous and Neogene geothermal gradients that were comparable with that at the present day, i.e. no significant increase in basal heat flow. Sonic velocity profiles logged in hydrocarbon boreholes constrain the minimum thickness of the eroded section, which varies between c. 1000 m in the centre and c. 2240 m at the margins of the basin. Given the strength of evidence for tectonic inversion in the St. George's Channel basin, our favoured model invokes superimposition of the effects of inversion and igneous underplating to account for the complex exhumation history of the St. George's Channel basin in particular, and the western UK basins in general. Williams Gareth A., Turner Jonathan P. and Holford Simon P. |
format |
Article in Journal/Newspaper |
author |
Williams, G. Turner, J. Holford, S. |
author_facet |
Williams, G. Turner, J. Holford, S. |
author_sort |
Williams, G. |
title |
Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
title_short |
Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
title_full |
Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
title_fullStr |
Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
title_full_unstemmed |
Inversion and exhumation of the St. George's Channel basin offshore Wales UK |
title_sort |
inversion and exhumation of the st. george's channel basin offshore wales uk |
publisher |
Geological Soc Publ House |
publishDate |
2005 |
url |
http://hdl.handle.net/2440/46941 https://doi.org/10.1144/0016-764904-023 |
long_lat |
ENVELOPE(132.817,132.817,67.178,67.178) |
geographic |
Bala |
geographic_facet |
Bala |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
http://dx.doi.org/10.1144/0016-764904-023 |
op_relation |
Journal of the Geological Society, 2005; 162(1):97-110 0016-7649 2041-479X http://hdl.handle.net/2440/46941 doi:10.1144/0016-764904-023 Holford, S. [0000-0002-4524-8822] |
op_doi |
https://doi.org/10.1144/0016-764904-023 |
container_title |
Journal of the Geological Society |
container_volume |
162 |
container_issue |
1 |
container_start_page |
97 |
op_container_end_page |
110 |
_version_ |
1786197294805155840 |