MAKE A MEME
View Large Image
| View Original: | The_Quarterly_journal_of_the_Geological_Society_of_London_(12645106773).jpg (1188x2004) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: The Quarterly journal of the Geological Society of London (12645106773).jpg 118 <br> PROCEEDINGS OF THE GEOLOGICAL SOCIETY NoV 1 <br> ; <br> obviously mechanical ; the resistance offered by the oblique sheet of <br> quartz to the pressure forward of the mass has caused the bending <br> of the sheets of slate at the ends which abut against the quartz <br> A slight change in the direction of the clea- <br> Fig 5 vage may frequently be observed in its passage <br> from one bed of rock to another arising pro- <br> / bably from beds of different hardness offering <br> different degrees of resistance to pressure <br> Figure 5 represents the section of a fragment <br> of slate from Langdale in which the thin beds <br> a a and h h are rather softer than the other beds <br> c c ; the lines y y show the direction of the <br> planes of cleavage which are perpendicular in <br> passing through the beds c c but dip 80° to the <br> southward in the beds a a and b b the beds <br> dipping to the north at an angle of 60° <br> Here the change in the direction of the <br> cleavage in passing from bed to bed is fully <br> 10° which is an unusual amount of deviation ; <br> but a variation of two or three degrees under <br> such circumstances is often met with The <br> K <br> cause of these irregularities must also be me- <br> chanical <br> The surface of particular beds of slate is <br> sometimes found broken up into a series of <br> steps parallel to the strike of the cleavage <br> the front of each step is formed by the plane <br> of cleavage and the top by a portion of the <br> bed which has been displaced from its original <br> position and appears to lie at an angle towards <br> f the original plane of bedding <br> 6 represents the section of a fragment of slate from the <br> Pilton beds two miles north of Barnstaple the upper broken <br> line a a shows the present form of the surface of a bed covered with 35268760 109512 51125 Page 118 Text v 5 http //www biodiversitylibrary org/page/35268760 1849 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 5 1849 Geology Periodicals Smithsonian Libraries bhl page 35268760 dc identifier http //biodiversitylibrary org/page/35268760 smithsonian libraries Information field Flickr posted date ISOdate 2014-02-20 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12645106773 2015-08-27 10 55 21 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1849 Photos uploaded from Flickr by Fæ using a script | ||||
.jpg){kind=link}
