MAKE A MEME
View Large Image
| View Original: | The_Quarterly_journal_of_the_Geological_Society_of_London_(12981111013).jpg (2032x1162) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: The Quarterly journal of the Geological Society of London (12981111013).jpg 204 <br> PEOCEEDIN GS OF THE GEOLOGICAL SOCIETY <br> M <br> S <br> TS <br> ts ® <br> co <br> 03 eg <br> 1-3 i <br> and unknown thickness White clay occurs round Lon- <br> don ; from this the bricks are made of which the town is <br> built The geologist may here travel twenty or thirty miles <br> without seeing rocks in place In the gravels near Hamilton <br> elephantine remains were found supposed by Dr Dawson <br> to have been washed from the table-land of the Niagara <br> escarpment when the lower plain was still covered by sea <br> Between Rochester and Scottsville the undulating sur- <br> face consists entirely of drift containing numerous boul- <br> ders of Potsdam sandstone labradorite gneiss hyper- <br> sthene-rock c from the Laurentine Chain about 100 miles <br> off Many of them are large smooth and well striated <br> Mr Hall observed that the drift is here often 120 feet thick <br> and that the mounds are steepest to the north <br> The River Genesee runs through a deep rocky ravine <br> which near Portage is 350 feet high The rock on the top <br> is smoothed and scratched and along the whole course of <br> the river on either side above the gorge the rocks are <br> generally obscured by drift On this river Dr Bigsby ob- <br> served fragments from Montreal Mountain which lies 270 <br> miles to the north-east ; and Laurentine boulders are com- <br> mon I observed at Mountmorris on the river that in <br> the lower part of the drift the stones are often angular and <br> scratched while the upper beds are of sand <br> Near Portage on the Genesee the drift is said by Mr <br> Hall to be about 500 feet thick filling up a valley in <br> the rocks through which an older river ran previous to <br> the drift-period When the country emerged from the <br> sea and a new drainage was formed the river was turned <br> aside by this accumulation finding it easier to form a <br> new channel in the present gorge 350 feet deep <br> At Onondaga the drift is 640 feet thick <br> Drift is equally characteristic of Connecticut and Mas- <br> sachusetts In the New Red Sandstone Valley of Con- <br> necticut the drift seemed mixed but mostly local <br> It is also well known that large far-transported boul- <br> ders occur on the south bank of the Ohio � a circum- <br> stance less remarkable than at first sight appears when <br> we consider that it is stated that icebergs have been seen <br> as far south as the Azores <br> Wherever the drift is freshly removed the <br> rocks are found to be smoothed striated and <br> often rounded On the Isle Perrot near Mon- <br> treal Mr Billings observed striae running S W ; <br> and near Ottawa by the river in several places <br> they run south-easterly These instances are <br> both at low levels ; and during a late period it is <br> easy to understand how during a former exten- <br> sion of the Gulf of St Lawrence icebergs drift- <br> ing up the Gulf as they do now would produce <br> scratches running S W in the strait between the <br> Laurentine hills and the Mountains of Adirondack <br> while in the open sea south of Ottawa now a <br> great plain the drift passed in an opposite direc- <br> tion About halfway between Ottawa and Pres- <br> cott on the St Lawrence near Kempville the striae 36161747 111474 51125 Page 204 Text v 15 http //www biodiversitylibrary org/page/36161747 1859 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 15 1859 Geology Periodicals Smithsonian Libraries bhl page 36161747 dc identifier http //biodiversitylibrary org/page/36161747 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-07 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/12981111013 2015-08-26 14 55 10 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1859 Photos uploaded from Flickr by Fæ using a script | ||||
.jpg){kind=link}
