http://earthwise.bgs.ac.uk/index.php?action=history&feed=atom&title=File%3AP519567.jpg 2026-07-03T00:03:39Z Revision history for this page on the wiki MediaWiki 1.42.3 http://earthwise.bgs.ac.uk/index.php?title=File:P519567.jpg&diff=31734&oldid=prev 2017-07-29T14:53:06Z

<p>User created page with UploadWizard</p> <p><b>New page</b></p><div>=={{int:filedesc}}==<br /> {{Information<br /> |description={{|1=Specimen of roofing slate quarried from Balvicar Quarry, Seil Island, Argyllshire, Scotland. Typical dark grey slate from the Easdale Slate belt, showing an original bedding structure. The specimen is of Precambrian, Dalradian age. British Geological Survey Petrology Collection sample number EMC 5743. The pale band is composed of slightly more silty material than the rest of the slate which is a dark mudstone material. Original bedding in slate was termed&#039;ribboning&#039;by the quarrymen. If it is too strongly developed it can reduce the quality of the slate, and can sometimes fracture. Slight differences in the proportions of clay and silt of different beds are reflected in the quality and appearance of the slate-rock into which the clays and silts are eventually transformed. Sediments deposited in different areas or at different geological times show variations allowing one group to be distinguished from another, so that for example the Ballachulish Slates differ from those of the Highland Border region. Specimen size: 21x8cm. P519567.}}<br /> |date=2017-07-29 15:51:17<br /> |source=British Geological Survey<br /> |author=British Geological Survey<br /> |permission=<br /> |other versions=<br /> }}<br /> <br /> =={{int:license-header}}==<br /> {{subst:Custom license marker added by UW}}<br /> {{BGS}}<br /> <br /> [[Category:Uploaded with UploadWizard]]</div>

Scotfot