MAKE A MEME View Large Image The Quarterly journal of the Geological Society of London (12961161455).jpg 256 <br> PROCEEDIlfGS OF THE GEOLOGICAL SOCIETY April 14 <br> ting The greater part of each vein is dead or unproductive ; <br> the productive portions or pockets ...
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Keywords: The Quarterly journal of the Geological Society of London (12961161455).jpg 256 <br> PROCEEDIlfGS OF THE GEOLOGICAL SOCIETY April 14 <br> ting The greater part of each vein is dead or unproductive ; <br> the productive portions or pockets vary from a few yards to 100 <br> fathoms in length and from a few inches to nearly 30 feet in thickness <br> The pockets are sometimes very close together sometimes more than <br> a mile apart in the same vein ; in all cases they are connected hy a <br> vein- track consisting chiefly of softened clay-slate and quartz <br> with occasionally a little iron-ore fig 2 <br> The pockets are found not to descend parallel to the line of <br> their dip but to slope endwise generally to the west but in one or <br> two cases to the east To this phenomenon the author gives the name <br> of end-slant He accounts for it in the following manner He <br> Fig 2 ” Longitudinal Section of a Vein <br> P i 'P <br> P <br> V t P t V <br> ppp Pockets ttt Vein-track <br> P <br> assumes that the veins have been segregated from the adjoining clay- <br> slate the unproductive portions occurring where the continuous <br> strata were not sufficiently impregnated with ferruginous matter to <br> produce a lode of ore the end-slant of each productive part being <br> determined by the line of intersection of the sloping plane of the <br> vein with the boundaries of the ferruginous portions at the com- <br> mencement and termination of each pocket ' <br> Discussion <br> Mr Etheeidge thought that the great iron-lodes of this district <br> lay in the great faults which traverse the country and in which <br> there had been considerable downthrow to the north In most <br> cases in the Bristol district the lodes seem to have been formed at <br> the bottom of the sea during the New-Red-Sandstone period by <br> infiltration of salts of iron into the faults <br> 3 On the Salt-mines of St Domingo By F Rttschhaupt <br> Communicated by Sir R I Murchison Bart K C B F E S Y P G S <br> Abridged <br> The author described the Cerro de Sal or Salt-mountain of St <br> Domingo as subordinate to the main chain of mountains run- <br> ning in a S E and N W direction its own direction being E S E <br> and W N W The eastern part of the Cerro de Sal is very rugged <br> and steep rising to 550 or 600 feet; towards the W it becomes <br> lower and forms a chain of irregular hills <br> See Quart Journ Geol Soc vol xxiv p 335 36103103 111288 51125 Page 256 Text v 25 http //www biodiversitylibrary org/page/36103103 1869 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 25 1869 Geology Periodicals Smithsonian Libraries bhl page 36103103 dc identifier http //biodiversitylibrary org/page/36103103 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-06 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12961161455 2015-08-26 15 51 40 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1869 Photos uploaded from Flickr by Fæ using a script
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