http://earthwise.bgs.ac.uk/index.php?action=history&feed=atom&title=File%3AP519583.jpg 2026-07-03T00:03:38Z Revision history for this page on the wiki MediaWiki 1.42.3 http://earthwise.bgs.ac.uk/index.php?title=File:P519583.jpg&diff=31749&oldid=prev 2017-07-29T14:53:28Z

<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 Ballachulish, Argyllshire, Scotland. Very dark grey slate with minor pyrite and relatively smooth surface. It is a roofing slate quarried from Ballachulish, Argyll, Scotland. The specimen is of Precambrian, Dalradian age. British Geological Survey Petrology Collection sample number EMC 5759. This variety, known as&#039;Oak&#039;has a very fine grain on the cleavage surface. Slaty cleavage is formed by the re-alignment and growth of new minerals as a result of intense pressure and temperature deep in the Earth&#039;s crust. Other minerals such as quartz and feldspar act as fillers giving the slate bulk and strength. Too much of these make a slate too thick with a coarse surface finish; too little and it is soft with low strength. Specimen size: 26x14cm. P519583.}}<br /> |date=2017-07-29 15:51:27<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