MAKE A MEME
View Large Image
| View Original: | The_Quarterly_journal_of_the_Geological_Society_of_London_(13937225462).jpg (1166x2104) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: The Quarterly journal of the Geological Society of London (13937225462).jpg COLLECTED IN MADAGASCAR BY REV R BAROtf 353 <br> yellow in colour Its crystals are remarkably well contoured ; they <br> are bounded by faces out of the prismatic zone terminated by a <br> dome or hemipyramid <br> Large pseudomorphs after hornblende occur sporadically They <br> are crowded with minute cubes of iron-ore distributed uniformly <br> through the crystal-section see fig 11 Between crossed nicols <br> Fig 11 ” Fused Hornblende-crystal recrystallized as Magnetite <br> and Augite in Magma-basalt X 70 <br> they usually give aggregate-polarization The polarizing substance <br> resembles augite probably produced by a melting-down of the <br> hornblende substance <br> A few grains of quartz similar to those already described are met <br> with occasionally The corroded grains are surrounded by a zone <br> of colourless glass containing augite-microlites ; this is succeeded by <br> a second zone of brown glass containing microlites and crystals of <br> augite together with granules of magnetite see fig 12 <br> Fig 12 ” Quartz-grain melted down and surrounded by light and <br> dark zones of Glass ivith Augite-microlites <br> The amount of glass increases in certain parts of the rock The <br> elongated shape of these more yitreous portions points to fluidal <br> movements during the hardening of the rock The central portions <br> of these patches are often filled with a network of minute opaque <br> trichites crossing one another at angles of 60° 90° and 120° fig 13 <br> Felspar-free basalts or magma-basalts Boficky have a wide-spread <br> occurrence They have been described for instance from the <br> Kaiserstuhl Rosenbusch the Ehon and Vogelsberg Bucking <br> 2c2 36940166 113696 51125 Page 351 Text 45 http //www biodiversitylibrary org/page/36940166 1889 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 45 1889 Geology Periodicals Smithsonian Libraries bhl page 36940166 dc identifier http //biodiversitylibrary org/page/36940166 smithsonian libraries Information field Flickr posted date ISOdate 2014-04-21 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/13937225462 2015-08-26 05 52 28 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1889 Photos uploaded from Flickr by Fæ using a script | ||||
.jpg){kind=link}
