MAKE A MEME
View Large Image
| View Original: | The_Quarterly_journal_of_the_Geological_Society_of_London_(14076434975).jpg (1192x2078) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: The Quarterly journal of the Geological Society of London (14076434975).jpg OLDER PERIDOTITES OF 8C0TLA D <br> 359 <br> parallel to those displayed by the granites and so well described by <br> Mr J A Phillips F E S Still more frequently the so-called <br> segregation veins of peridotite are seen traversing the gabbro <br> and similar veins of gabbro are found intersecting the peridotite <br> masses IS ot unfrequently too such veins are found composed of <br> picrite eucrite or troctolite That these so-called segregation <br> or contemporaneous veins have been formed at different times is <br> shown by the fact that one vein is frequently intersected and shifted <br> in position by another A beautiful example of this kind is illus- <br> trated in the annexed diagram <br> Intersecting Veins of Gabbro and Dunite in Olivine EocJc nat size <br> a Olivine rock dunite <br> b Olivine-gabbro vein traversing the same <br> c Segregation-nodule of felspathie rock <br> d Porphyritic dunite intersecting and shifting the gabbro-vein <br> As is not uncommonly the case with such veins the minerals in <br> them have sometimes a special arrangement of their own Thus in <br> the case figured above the olivine-gabbro -vein 6 has its felspar <br> grouped principally along the sides and the augite and olivine in the <br> centre <br> The relations of the gabbros and peridotites in the Western Isles <br> of Scotland seem to indicate that in the heart of these old volcanoes <br> the felspar olivine and augite tended to segregate in certaia cases <br> into masses of various dimensions ; and that these masses were after <br> consolidation fissured again and again the fissures being injected by <br> different portions of the magma which were still in a more or less <br> plastic condition <br> The very close association of peridotites with gabbros is not by <br> any means peculiar to the district we are describing In the Hartz <br> in ITassau in Baden in Silesia and in many other districts a similar <br> association of rocks prevails and in many if not all of these cases <br> Quart Journ Geol Soc vol xxxvi 1880 p 1 <br> 2 c2 37047229 114009 51125 Page 359 Text 41 http //www biodiversitylibrary org/page/37047229 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 37047229 dc identifier http //biodiversitylibrary org/page/37047229 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 N02/14076434975 2015-08-26 04 55 44 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 | ||||
.jpg){kind=link}
