Skip to main content

Main menu

  • Home
    • Journal home
    • Lyell Collection home
    • Geological Society home
  • Content
    • Online First
    • Issue in progress
    • All issues
    • Thematic Collections
    • Supplementary publications
    • Open Access
  • Subscribe
    • GSL fellows
    • Institutions
    • Corporate
    • Other member types
  • Info
    • Authors
    • Librarians
    • Readers
    • GSL Fellows access
    • Other member type access
    • Press office
    • Accessibility
    • Help
    • Metrics
  • Alert sign up
    • eTOC alerts
    • Online First alerts
    • RSS feeds
    • Newsletters
    • GSL blog
  • Submit
  • 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
Journal of the Geological Society
  • 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
Journal of the Geological Society

Advanced search

  • Home
    • Journal home
    • Lyell Collection home
    • Geological Society home
  • Content
    • Online First
    • Issue in progress
    • All issues
    • Thematic Collections
    • Supplementary publications
    • Open Access
  • Subscribe
    • GSL fellows
    • Institutions
    • Corporate
    • Other member types
  • Info
    • Authors
    • Librarians
    • Readers
    • GSL Fellows access
    • Other member type access
    • Press office
    • Accessibility
    • Help
    • Metrics
  • Alert sign up
    • eTOC alerts
    • Online First alerts
    • RSS feeds
    • Newsletters
    • GSL blog
  • Submit

AUTOMETASOMATISM IN THE LOWER SPILITES OF THE BUILTH VOLCANIC SERIES

GEOFFREY DENNIS NICHOLLS
Quarterly Journal of the Geological Society, 114, 137-162, 1 November 1958, https://doi.org/10.1144/gsjgs.114.1.0137
GEOFFREY DENNIS NICHOLLS
  • Find this author on Google Scholar
  • Search for this author on this site
PreviousNext
  • Article
  • Info & Metrics
  • PDF
Loading

Abstract

The Lower Spilite formation of the Builth Volcanic Series is made up of numerous thin flows of strongly porphyritic and amygdaloidal lava. Less metasomatized specimens are composed of albite-oligoclase and chlorite with smaller amounts of pyroxene and sphene. Strongly metasomatized examples show conversion of the aibite-oligoclase to albite and replacement of chlorite, including that of the amygdales, by albite plus or minus quartz. Chemical data show that these rocks have gained Na and Si and lost Al, Ca, Mg, Fe and H2O.

Rarely, individual sacs can be extracted from the rock. Their margins are richer in Mg, Fe and H2O than their cores and an example is described in which a Ca–Mg–Fe metasomatism has caused replacement of plagioclase by pumpellyite.

In explanation of the observations, immiscibility of two liquid phases is suggested: one the silicate residual magmatic liquid, the other a liquid enriched in Mg, Fe, H2O and probably Ca and CO2. The amygdales arise by the separation and subsequent crystallization of this second liquid. Segregation of this phase within the magma can account for most of the variation observed in these lavas, the margins of the sacs being relatively enriched in the second phase and the strongly meta-somatized lavas correspondingly impoverished.

  • © Geological Society of London 1958

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 sales@geolsoc.org.uk

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 sales@geolsoc.org.uk

PreviousNext
Back to top

In this issue

Quarterly Journal of the Geological Society: 114 (1-4)
Quarterly Journal of the Geological Society
Volume 114, Issue 1-4
November 1958
  • Table of Contents
  • Table of Contents (PDF)
  • Index by author
  • Back Matter (PDF)
  • Front Matter (PDF)
Alerts
Sign In to Email Alerts with your Email Address
Citation tools

AUTOMETASOMATISM IN THE LOWER SPILITES OF THE BUILTH VOLCANIC SERIES

GEOFFREY DENNIS NICHOLLS
Quarterly Journal of the Geological Society, 114, 137-162, 1 November 1958, https://doi.org/10.1144/gsjgs.114.1.0137
GEOFFREY DENNIS NICHOLLS
  • 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

AUTOMETASOMATISM IN THE LOWER SPILITES OF THE BUILTH VOLCANIC SERIES

GEOFFREY DENNIS NICHOLLS
Quarterly Journal of the Geological Society, 114, 137-162, 1 November 1958, https://doi.org/10.1144/gsjgs.114.1.0137
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
Email to

Thank you for sharing this Journal of the Geological Society 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.
AUTOMETASOMATISM IN THE LOWER SPILITES OF THE BUILTH VOLCANIC SERIES
(Your Name) has forwarded a page to you from Journal of the Geological Society
(Your Name) thought you would be interested in this article in Journal of the Geological Society.
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
  • Sketch-based interface and modelling of stratigraphy and structure in three dimensions
  • The Nonesuch Formation Lagerstätte: a rare window into freshwater life one billion years ago
  • Geological Society of London Scientific Statement: what the geological record tells us about our present and future climate
  • Terrestrial stratigraphical division in the Quaternary and its correlation
  • The nature and origins of decametre-scale porosity in Ordovician carbonate rocks, Halahatang oilfield, Tarim Basin, China
More...

Journal of the Geological Society

  • About the journal
  • Editorial Board
  • Submit a manuscript
  • 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 
0016-7649
Online ISSN 
2041-479X

Copyright © 2021 Geological Society of London