TY - JOUR
T1 - Using U–Pb carbonate dating to constrain the timing of extension and fault reactivation within the Bristol Channel Basin, SW England
AU - Connolly, Joe
AU - Anderson, Mark
AU - Mottram, Catherine
AU - Price, Gregory D.
AU - Parrish, Randall
AU - Sanderson, David
N1 - Publisher Copyright:
© 2024 The Author(s).
PY - 2024/9/2
Y1 - 2024/9/2
N2 - The Bristol Channel Basin is a Mesozoic continental rift basin. The basin is an important analogue for offshore reservoirs. Relative cross-cutting relationships and correlation with adjacent sedimentary basins have previously been used to constrain the timing of basin development. In situ U–Pb carbonate geochronology has been used to date calcite slickenfibre development in the cores of normal, thrust and strike-slip faults in the East Quantoxhead and Kilve region of Somerset for the first time. Protracted north–south extension from c. 150 to 120 Ma formed normal faults. Subsequent north–south shortening from c. 50 to 20 Ma was accommodated by (1) mutually cross-cutting strike-slip faults, (2) minor east–west-striking thrust faults and (3) the reactivation of pre-existing normal faults. Throughout Cenozoic contraction, σ2 and σ3 remained similar in magnitude and periodically flipped to become vertical; this was probably controlled by local stress permutations and changes in fluid pressure. The timing of inversion is contemporaneous with dominant Pyrenean and later Alpine orogenic events, as well as the opening of the Mid-Atlantic Rift. Early inversion of the Bristol Channel Basin was probably driven by far-field Pyrenean deformation, with later contraction caused by Alpine forces. Ridge push from the Mid-Atlantic Rift exacerbated the reactivation of the basin.
AB - The Bristol Channel Basin is a Mesozoic continental rift basin. The basin is an important analogue for offshore reservoirs. Relative cross-cutting relationships and correlation with adjacent sedimentary basins have previously been used to constrain the timing of basin development. In situ U–Pb carbonate geochronology has been used to date calcite slickenfibre development in the cores of normal, thrust and strike-slip faults in the East Quantoxhead and Kilve region of Somerset for the first time. Protracted north–south extension from c. 150 to 120 Ma formed normal faults. Subsequent north–south shortening from c. 50 to 20 Ma was accommodated by (1) mutually cross-cutting strike-slip faults, (2) minor east–west-striking thrust faults and (3) the reactivation of pre-existing normal faults. Throughout Cenozoic contraction, σ2 and σ3 remained similar in magnitude and periodically flipped to become vertical; this was probably controlled by local stress permutations and changes in fluid pressure. The timing of inversion is contemporaneous with dominant Pyrenean and later Alpine orogenic events, as well as the opening of the Mid-Atlantic Rift. Early inversion of the Bristol Channel Basin was probably driven by far-field Pyrenean deformation, with later contraction caused by Alpine forces. Ridge push from the Mid-Atlantic Rift exacerbated the reactivation of the basin.
UR - http://www.scopus.com/inward/record.url?scp=85201092871&partnerID=8YFLogxK
UR - https://doi.org/10.6084/m9.figshare.c.7293400
UR - https://pearl.plymouth.ac.uk/context/gees-research/article/2025/viewcontent/jgs2024_021.pdf
U2 - 10.1144/jgs2024-021
DO - 10.1144/jgs2024-021
M3 - Article
AN - SCOPUS:85201092871
SN - 0016-7649
VL - 181
JO - Journal of the Geological Society
JF - Journal of the Geological Society
IS - 5
M1 - jgs2024-021
ER -