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abundant amount angle appears Author bands base beds cent Chalk character clay cleavage close common considerable consists contain deposits described developed direction distance district east evidence examination exposed extent fact fault feet figured folding fossils fragments further Geol Geological glacial grains green ground Hill horizon important inches included indicate interesting intrusion latter length less limestone localities lower margin marked mass material miles mineral movement nature nearly numerous observed obtained occur origin parallel pass plates portion possible present probably Productus Prof quarry quartz Ranges referred regard relation remarkable represented result ridge River rocks sand sandstone scale seems seen separated shales shown side similar slates species specimens stream structure suggested surface thickness traced typical upper usually valley whole zone
Página 142 - In Logan's original classification of the Laurentian this term — apart from the Upper Laurentian which was proved to be composed essentially of anorthosite intrusions — included two series differing in character, namely, the Lower Orthoclase (Fundamental Gneiss) and the Grenville series. Now that investigations have shown that these two series differ in origin, one being essentially a great development of very ancient sediments, and the other consisting of great bodies of igneous rock intruded...
Página 128 - Towards the north-west, however, the granite, in ever-increasing amount, arches up the sedimentary series and wells up through it, in places disintegrating it into a breccia composed of shreds and patches of the invaded rock scattered through the invading granite, until eventually connected areas of the sedimentary series disappear entirely and over hundreds of square miles the granite and granite-gneiss alone are seen, holding, however, in almost every exposure, inclusions which represent the last...
Página 136 - Certain granular amphibolites represent altered igneous intrusions, for they are found in the form of dykes cutting across the stratified white crystalline limestone, on the shores of Jack's Lake in the township of Methuen. The limestones here dip at a low angle to the south, and are excellently exposed in the form of low cliffs about the side of the lake.
Página cxiii - Balk will, who has filled the office of honorary treasurer for the last nine years and has now found himself unable to continue in the position. His books have been kept with great neatness and accuracy, and his attention to the business of the Society has always been prompt and...
Página 668 - ... to accompany the medal, the remaining interest to be given in one or more portions, at the discretion of the council, for the encouragement of geology or of any of the allied sciences by which they shall consider geology to have been most materially advanced, either for travelling expenses or for a memoir or paper published or in progress, and without reference to the sex or nationality of the author or the language in which any such memoir or paper may be written.
Página 135 - These amphibolites are not peculiar to this area, but occur abundantly everywhere in the Laurentian. They have always proved to be one of the chief difficulties in the way of a correct understanding of the geology of this system, seeing that it has been impossible to do more than indulge in conjectures concerning their origin. The same difficulty has been...
Página xx - as an acknowledgment of eminent services in any department of Geology, irrespective of the receiver's country ; but he must not be older than 45 years at his last birthday, thus probably not too old for further work, and not too young to have done much.
Página 136 - I remarkable convergence of type, whereby rocks of widely different origin come to assume identity of character, explains the difficulty which has been experienced up to the present time in arriving at a satisfactory conclusion concerning their genetic relations. (a) Some of these amphibolites result from the metamorphism and recrystallization of sediments. To this class belong the feather-amphibolites above described, which usually occur in thin bands alternating with crystalline limestone, and...
Página 144 - ... however, probably developed only a small part of the space which the granite now occupies ; (5) the invading granite not only exerted a mechanical action upon the invaded strata, but also gave rise to a variety of metamorphic products, among others amphibolite produced by its action in the limestone, which accounts for the fact that while the invaded strata are chiefly limestone, the fragments of the latter, where found in the granite, consist of amphibolite ; (6) the invading bathyliths...
Página 144 - The granite-gneiss of the bathyliths not only arched up the invaded strata into a series of domes, but ' stoped ' out portions of the sides and lower surface of the arches, the fragments torn off from walls and roof by the invading granite being found scattered throughout the mass of the invading rock : this