Skip to main content

Main menu

  • Home
    • Series home
    • Lyell Collection home
    • Geological Society home
  • Content
    • Online First
    • Current volume
    • All volumes
    • All collections
    • Supplementary publications
    • Open Access
  • Subscribe
    • GSL fellows
    • Institutions
    • Corporate
    • Other member types
  • Info
    • Authors
    • Librarians
    • Readers
    • Access for GSL Fellows
    • Access for other member types
    • Press office
    • Accessibility
    • Help
  • Alert sign up
    • eTOC alerts
    • Online First alerts
    • RSS feeds
    • Newsletters
    • GSL blog
  • Propose
  • Geological Society of London Publications
    • Engineering Geology Special Publications
    • Geochemistry: Exploration, Environment, Analysis
    • Journal of Micropalaeontology
    • Journal of the Geological Society
    • Lyell Collection home
    • Memoirs
    • Petroleum Geology Conference Series
    • Petroleum Geoscience
    • Proceedings of the Yorkshire Geological Society
    • Quarterly Journal of Engineering Geology and Hydrogeology
    • Quarterly Journal of the Geological Society
    • Scottish Journal of Geology
    • Special Publications
    • Transactions of the Edinburgh Geological Society
    • Transactions of the Geological Society of Glasgow
    • Transactions of the Geological Society of London

User menu

  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
Geological Society, London, Special Publications
  • Geological Society of London Publications
    • Engineering Geology Special Publications
    • Geochemistry: Exploration, Environment, Analysis
    • Journal of Micropalaeontology
    • Journal of the Geological Society
    • Lyell Collection home
    • Memoirs
    • Petroleum Geology Conference Series
    • Petroleum Geoscience
    • Proceedings of the Yorkshire Geological Society
    • Quarterly Journal of Engineering Geology and Hydrogeology
    • Quarterly Journal of the Geological Society
    • Scottish Journal of Geology
    • Special Publications
    • Transactions of the Edinburgh Geological Society
    • Transactions of the Geological Society of Glasgow
    • Transactions of the Geological Society of London
  • My alerts
  • Log in
  • My Cart
  • Follow gsl on Twitter
  • Visit gsl on Facebook
  • Visit gsl on Youtube
  • Visit gsl on Linkedin
Geological Society, London, Special Publications

Advanced search

  • Home
    • Series home
    • Lyell Collection home
    • Geological Society home
  • Content
    • Online First
    • Current volume
    • All volumes
    • All collections
    • Supplementary publications
    • Open Access
  • Subscribe
    • GSL fellows
    • Institutions
    • Corporate
    • Other member types
  • Info
    • Authors
    • Librarians
    • Readers
    • Access for GSL Fellows
    • Access for other member types
    • Press office
    • Accessibility
    • Help
  • Alert sign up
    • eTOC alerts
    • Online First alerts
    • RSS feeds
    • Newsletters
    • GSL blog
  • Propose

Structural analysis of the inverted Bristol Channel Basin: implications for the geometry and timing of fracture porosity

Michal Nemčok, Rod Gayer and Marios Miliorizos
Geological Society, London, Special Publications, 88, 355-392, 1 January 1995, https://doi.org/10.1144/GSL.SP.1995.088.01.20
Michal Nemčok
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Search for this author on this site
Rod Gayer
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Search for this author on this site
Marios Miliorizos
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Search for this author on this site
PreviousNext
  • Article
  • Info & Metrics
  • PDF
Loading

Abstract

The Bristol Channel basin was developed as an early Mesozoic half-graben, with the Bristol Channel fault zone (BCFZ) representing the principal down-to-the-south basin controlling structure. The basin was inverted during the Tertiary. This paper illustrates the application of structural analysis to the northern and southern margins of the Bristol Channel basin, where on shore medium- to small-scale structures provide analogues for the BCFZ. Throughout the outcrop four distinct structural mechanisms and associated fracture systems can be recognised. i) The oldest are normal faults, in many cases resulting from the reactivation of underlying WNW-ESE to NE-SW Late Palaeozoic Variscan thrusts. These are linked by N-S transfer faults and associated with WNW-ESE to ENE-WSW extensional veins. Evidence for synsedimentary development of both normal faults and extensional veins has been found in the Triassic and Lower Liassic sequences. Palaeostress analysis suggests an approximately NE-SW oriented σ3. ii) During inversion the normal faults acted as buttresses, forming WNW-ESE and younger NW-SE trending folds. Associated thrusts and oblique- to strike-slip faults reactivated the earlier transfer faults. The orientation of σ1 was NE-SW during this deformation. iii) A regionally consistent system of NE-SW striking extensional veins formed at the close of the strike-slip inversion event. iv) Following primary inversion, lateral escape structures formed against the buttresses, with the development of oblique- and strike-slip faults in a variable and locally controlled stress field. Fracture porosity determined at sites throughout the outcrop show highest levels, up to 20%, formed in association with normal faults during the rifting event, but also significant amounts developed during the inversion event. Veins associated with strike-slip faulting of the latter give average porosities of 6.5%, whilst the later inversion-related extensional veins give average porosities of 0.8%. All these porosities show a high degree of directional permeability. It is argued that the oil generation window was reached during burial in the later stages of the rifting event, and that rapid polyphase fluid discharge from over-pressured fracture-bounded compartments allowed hydrocarbon migration into normal fault-related fracture porosity to form traps. The development of fracture porosity during inversion produced a long-lasting directed permeability and allowed many of the traps to drain. Only those traps associated with normal faults not directly affected by the inversion will have survived. A strategy to discover such a play requires a well targeted and detailed structural study.

  • © The Geological Society 1995

Please note that if you are logged into the Lyell Collection and attempt to access content that is outside of your subscription entitlement you will be presented with a new login screen. You have the option to pay to view this content if you choose. Please see the relevant links below for further assistance.

INDIVIDUALS

Log in using your username and password

– GSL fellows: log in with your Lyell username and password. (Please check your access entitlements at https://www.geolsoc.org.uk/fellowsaccess)
– Other users: log in with the username and password you created when you registered. Help for other users is at https://www.geolsoc.org.uk/lyellcollection_faqs
Forgot your username or password?

Purchase access

You may purchase access to this article for 24 hours and download the PDF within the access period. This will require you to create an account if you don't already have one. To download the PDF, click the 'Purchased Content' link in the receipt email.

LIBRARY USERS

Log in through your institution

You may be able to gain access using your login credentials for your institution. Contact your library if you do not have a username and password.
If your organization uses OpenAthens, you can log in using your OpenAthens username and password. To check if your institution is supported, please see this list. Contact your library for more details.
If you think you should have access, please contact your librarian or email [email protected]

LIBRARIANS

Administer your subscription.

CONTACT US

If you have any questions about the Lyell Collection publications website, please see the access help page or contact [email protected]

PreviousNext
Back to top

In this volume

Geological Society, London, Special Publications: 88 (1)
Geological Society, London, Special Publications
Volume 88
1995
  • Table of Contents
  • Table of Contents (PDF)
  • About the Cover
  • Index by author
  • Back Matter (PDF)
  • Front Matter (PDF)
Alerts
Sign In to Email Alerts with your Email Address
Citation tools

Structural analysis of the inverted Bristol Channel Basin: implications for the geometry and timing of fracture porosity

Michal Nemčok, Rod Gayer and Marios Miliorizos
Geological Society, London, Special Publications, 88, 355-392, 1 January 1995, https://doi.org/10.1144/GSL.SP.1995.088.01.20
Michal Nemčok
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Rod Gayer
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Marios Miliorizos
Laboratory for Strain Analysis, Department of Earth Sciences, University of Wales Cardiff, CF1 3YE, UK
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Permissions
View PDF
Share

Structural analysis of the inverted Bristol Channel Basin: implications for the geometry and timing of fracture porosity

Michal Nemčok, Rod Gayer and Marios Miliorizos
Geological Society, London, Special Publications, 88, 355-392, 1 January 1995, https://doi.org/10.1144/GSL.SP.1995.088.01.20
del.icio.us logo Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
Email to

Thank you for sharing this Geological Society, London, Special Publications article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Structural analysis of the inverted Bristol Channel Basin: implications for the geometry and timing of fracture porosity
(Your Name) has forwarded a page to you from Geological Society, London, Special Publications
(Your Name) thought you would be interested in this article in Geological Society, London, Special Publications.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
  • Tweet Widget
  • Facebook Like
  • Google Plus One
  • Article
  • Info & Metrics
  • PDF

Related Articles

Similar Articles

Cited By...

  • Most read
  • Most cited
Loading
  • The history of the European oil and gas industry (1600s–2000s)
  • Introduction to Himalayan tectonics: a modern synthesis
  • Himalayan earthquakes: a review of historical seismicity and early 21st century slip potential
  • New prospects on the cranial evolution of non-avialan paravian theropods based on geometric morphometrics
  • An introduction to forensic soil science and forensic geology: a synthesis
More...

Special Publications

  • About the series
  • Books Editorial Committee
  • Submit a book proposal
  • Author information
  • Supplementary Publications
  • Subscribe
  • Pay per view
  • Alerts & RSS
  • Copyright & Permissions
  • Activate Online Subscription
  • Feedback
  • Help

Lyell Collection

  • About the Lyell Collection
  • Lyell Collection homepage
  • Collections
  • Open Access Collection
  • Open Access Policy
  • Lyell Collection access help
  • Recommend to your Library
  • Lyell Collection Sponsors
  • MARC records
  • Digital preservation
  • Developing countries
  • Geofacets
  • Manage your account
  • Cookies

The Geological Society

  • About the Society
  • Join the Society
  • Benefits for Members
  • Online Bookshop
  • Publishing policies
  • Awards, Grants & Bursaries
  • Education & Careers
  • Events
  • Geoscientist Online
  • Library & Information Services
  • Policy & Media
  • Society blog
  • Contact the Society

Published by The Geological Society of London, registered charity number 210161

Print ISSN 
0305-8719
Online ISSN 
2041-4927

Copyright © 2022 Geological Society of London