http://earthwise.bgs.ac.uk/index.php?action=history&feed=atom&title=File%3AP519599.jpg 2026-07-03T01:51:16Z Revision history for this page on the wiki MediaWiki 1.42.3 http://earthwise.bgs.ac.uk/index.php?title=File:P519599.jpg&diff=31764&oldid=prev 2017-07-29T14:53:50Z

<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 from Aberfoyle Slate Quarries, Perthshire, Scotland. Dark grey slate, termed&#039;blue variety&#039;, showing very strong banding or&#039;ribboning&#039;. The specimen is of Precambrian, Dalradian age. British Geological Survey Petrology Collection sample number EMC 5774. Ribboning occurs when the original sedimentary bedding surfaces intersect the slaty cleavage surface. It shows the original nature of the mudstone or siltstone sedimentary rock from which the slate has formed as a result of metamorphic processes. The bands represent slightly different periods of sediment deposition, when conditions would vary. Some bands are thin and dark and represent very fine-grained periods of deposition. Others are lighter and coarser-grained, representing deposition of fine sand or silty sediments. P519599.}}<br /> |date=2017-07-29 15:51:42<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