Keywords: The Quarterly journal of the Geological Society of London (13889736199).jpg PROF A H GREEN ON A SECTION NEAR LLANBERTS <br> 75 <br> grey with very smooth fracture <br> not unlike that of the felsite but <br> the rock is soft enough to be <br> scratched by the knife and slightly <br> soapy to the touch it contains <br> many blebs of quartz and fragments <br> of other minerals and rocks all very <br> much altered it is very decidedly <br> but rudely cleaved and the clea- <br> vage-planes bend in a wavy way <br> round the fragments The surfaces <br> bounding this band of rock are <br> parallel to the laminae of the rock <br> A The rock C that comes next <br> is a breccia with a dark grey ma- <br> trix; the fragments are all flat- <br> tened and lie with their flat faces in <br> the same direction ; there is a rude <br> wavy cleavage with a tendency to <br> bend round the fragments We <br> have here then three bands of <br> rock all differing in lithological <br> character and separated from one <br> another by parallel and nearly <br> vertical planes ; one of these bands <br> A is made up of numerous <br> laminae each differing from its <br> neighbour in composition and these <br> laminae are aU parallel to one <br> another and to the planes which <br> separate A from B and B from C <br> These facts it seems to me admit <br> of only one interpretation The <br> rocks are bedded and in a nearly <br> vertical position ; there is clea- <br> vage as well and the cleavage and <br> bedding coincide ; but while the <br> flakiness of the rocks B and C is <br> due to rude cleavage the plane <br> separating these rocks from one <br> another the plane separating B <br> from A and the planes of lamina- <br> tion in A must I think be planes <br> of bedding <br> These flaky rocks occupy the <br> whole face of the cutting for a space <br> of about twenty yards but towards <br> the north-west end a capping of <br> conglomerate comes on above them <br> The junction slopes down to the <br> - Quartz-felsite i <br> -Conglomerate <br> -Dyke <br> G-rits with some <br> slaty beds <br> -Dyke <br> Grits <br> Dyke <br> 21 <br> i <br> Dyke in con- <br> glomerate <br> Grit <br> Conglomerate <br> and breccia <br> _MassiTe grit <br> Slate <br> 0 <br> So <br> O ” I <br> <br> -§ <br> f <br> I- 37046913 114009 51125 Page 75 Text 41 http //www biodiversitylibrary org/page/37046913 1885 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 41 1885 Geology Periodicals Smithsonian Libraries bhl page 37046913 dc identifier http //biodiversitylibrary org/page/37046913 smithsonian libraries Information field Flickr posted date ISOdate 2014-04-30 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/13889736199 2015-08-26 04 58 40 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1885 Photos uploaded from Flickr by Fæ using a script |