MAKE A MEME View Large Image The Quarterly journal of the Geological Society of London (12893760233).jpg 472 <br> ME J PAEEItfSON ON SOME <br> Dec 1897 <br> directions There are also fine quartz-veins which have probably <br> formed the means of supply to what can be ...
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Keywords: The Quarterly journal of the Geological Society of London (12893760233).jpg 472 <br> ME J PAEEItfSON ON SOME <br> Dec 1897 <br> directions There are also fine quartz-veins which have probably <br> formed the means of supply to what can be scarcely other than a <br> vesicle <br> It must be understood that this nodular structure if indeed it <br> may be called such occurs only in one or two specimens and it is <br> merely the suspicion that other and better known cases are due to <br> the same causes that has led me to record it here <br> Before passing on to consider the true fragmental rocks some <br> notice must be taken of a variety having an appearance in the field <br> strongly suggestive of a f el stone-agglomerate <br> In it white angular or subangular fragments with a tendency to <br> roughly resemble an almond in shape of an average length of \ inch <br> but which vary considerably are embedded in a softish black <br> or green-black matrix which in places contains foreign-looking <br> fragments the whole presenting a well-marked type of some <br> constancy <br> Rock with white fragments due to jlow-brecciation <br> The clotted portions represent the soft black matrix <br> In places the pieces of felstone are separated by a space consider- <br> able in proportion to their bulk ; in others they are close together <br> and the appearance is then suggestive of a slight cracking followed <br> by a forcing apart by a second material <br> It is evident that such an appearance as this might be produced <br> by a brecciating force after the consolidation of the rock subsequent <br> infiltration giving rise to the black matrix in which the fragments <br> are set But it is also clear that if such be the right interpretation <br> the magnitude of the force capable of moving neighbouring pieces <br> of rock apart and often of leaving fragments of different structure <br> in close proximity would have been sufficient to leave a clear <br> impress at all events microscopically Of this however there is no <br> indication except in one instance of a brecciated felspar; if other <br> cases had been present they would no doubt have been visible ; on <br> the contrary the evidence points sometimes the other way as in 36029315 111130 51125 Page 472 Text 53 http //www biodiversitylibrary org/page/36029315 1897 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 53 1897 Geology Periodicals Smithsonian Libraries bhl page 36029315 dc identifier http //biodiversitylibrary org/page/36029315 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-03 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12893760233 2015-08-26 16 51 30 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1897 Photos uploaded from Flickr by Fæ using a script
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