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| Keywords: The Quarterly journal of the Geological Society of London (13368714145).jpg 1872 <br> HICKS- TREMADOC ROCKS <br> 41 <br> stratified with grey flaky slate containing LinguleUa Davisii in great <br> abundance They graduate by almost insensible degrees from these <br> as hard grey flags then bluish grey with some thick-bedded rock of <br> tough texture They have a thickness of nearly 1000 feet with an <br> average dip of about 60° and the strike of the beds is from N E to <br> S W They form the north-east point of the island and are exposed <br> in an excellent coast-section with the Lingula-fiags dipping under <br> them and the dark iron-stained Arenig slates resting upon them <br> It is doubtful however whether the latter rest conformably upon <br> them I am inclined to think that a fault intervenes and that the <br> proper thickness as shown at some of the other places does not <br> occur here in consequence <br> Fig 2 Section across the northern part of Ramsey Island see Map <br> W Fault E <br> 5 Lingula-flags <br> 6 Tremadoc rocks <br> 7 Arenig rocks <br> At Whitesand Bay they also rest conformably on Lingula-flags ; <br> but a fault running up in a north-east direction and almost in the <br> strike of the beds has removed more than three fourths of their <br> thickness and has brought down the Arenig group in contact with <br> them so as to give it an appearance of resting almost conformably <br> upon them Further north near Llanveran the fault has gone <br> eastward of the series and they are seen again in nearly their entire <br> thickness underlying the Arenig group <br> The third patch at Tremanhire in the middle of the country <br> east of St David's occupies a greater area ; but there are only a <br> few quarries open and therefore considerable difficulty has been <br> experienced in defining its proper limits The Lingula-flags seem <br> everywhere to underlie the series here as at the other places ; but <br> the Arenig rocks only come in unconformably at the N E end of <br> the patch The beds have very much the same character as at <br> Ramsey Island with the exception that the middle portion is more <br> of a sandstone in parts and less cleaved Some of the most perfect <br> specimens have been found in these last-mentioned beds near and at <br> a place called Paran on the map <br> On the whole however Ramsey Island offers the hest advantages <br> for examining these rocks and also for obtaining fossils as the beds <br> are there well exposed and literally in some parts almost entirely <br> made up of organic remains <br> The species which have been discovered in these rocks with the <br> exception of LinguleUa Davisii are all new as well as a few of the <br> genera They comprise a new genus of Trilobites which I have <br> named Neseurctus and of which there are several species This <br> genus forms an interesting stage between the earlier Conocoryphe 39050887 120601 51125 Page 41 Text v 29 http //www biodiversitylibrary org/page/39050887 1873 Geological Society of London NameFound Conocoryphe NameConfirmed Conocoryphe EOLID 4320747 NameBankID 2875722 Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 29 1873 Geology Periodicals Smithsonian Libraries bhl page 39050887 dc identifier http //biodiversitylibrary org/page/39050887 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-24 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/13368714145 2015-08-26 10 50 32 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1873 Photos uploaded from Flickr by FÌ using a script | ||||
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