The Journal of Geology, Volume 1; Volumes 13-14University of Chicago Press, 1893 - Electronic journals Vols. for 1893-1923 includes section: "Reviews." |
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Page 2
... strata of the Cam- brian system are there traceable for a distance of more than 100 miles , reposing with a strong unconformability upon all rocks of older date . They consist of dolomitic shales with Olenellus , resting upon a thick ...
... strata of the Cam- brian system are there traceable for a distance of more than 100 miles , reposing with a strong unconformability upon all rocks of older date . They consist of dolomitic shales with Olenellus , resting upon a thick ...
Page 4
... strata in the same section of pre - Cambrian time . But so much uncertainty exists as to the application of this term Archæan , examples are so multiplying wherein what was supposed to be the oldest and truly Archæan rock is found to be ...
... strata in the same section of pre - Cambrian time . But so much uncertainty exists as to the application of this term Archæan , examples are so multiplying wherein what was supposed to be the oldest and truly Archæan rock is found to be ...
Page 7
... strata are quite unaltered . Indeed , in general aspect they look as young as the old red sandstones with which Hugh Miller identified them . It is at first hard to believe that such flat undisturbed sandstones are of higher antiquity ...
... strata are quite unaltered . Indeed , in general aspect they look as young as the old red sandstones with which Hugh Miller identified them . It is at first hard to believe that such flat undisturbed sandstones are of higher antiquity ...
Page 8
... strata , and like them dip , generally at gentle angles , towards the east . It was the opinion of Murchison , and was commonly admitted by geologists , that these overlying schists represented a thick group of sediments , which ...
... strata , and like them dip , generally at gentle angles , towards the east . It was the opinion of Murchison , and was commonly admitted by geologists , that these overlying schists represented a thick group of sediments , which ...
Page 9
... strata , are roughly parallel with the bedding planes of these strata . In this region , therefore , we have striking proofs of a stupen- dous post - Cambrian regional metamorphism . But there is still much uncertainty regarding the ...
... strata , are roughly parallel with the bedding planes of these strata . In this region , therefore , we have striking proofs of a stupen- dous post - Cambrian regional metamorphism . But there is still much uncertainty regarding the ...
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Common terms and phrases
anorthosite Archean augite basal basin beds belt boulders calcareous Cambrian carbonate of lime carbonic acid Carboniferous character chemical coal coast conglomerate Cretaceous crystalline crystals deposits diabases diallage drainage drift eastern englacial erosion eruptive evidence exhibit fact feet feldspar folding formation fossils gabbro Geol Geological Survey geologists glacial epoch glacier gneiss granite gravels hornblende Huronian ice-sheet igneous iron and manganese Jour Keweenawan Lake Superior later Laurentian lavas limestone lower magma manganese mass material metamorphism miles mineral moraine mountain observations occur ocean olivine origin oxide paleolithic Paleozoic phenomena plagioclase porphyritic portion pre-Cambrian present probably Professor pyroxene quartz quartzite region rhyolites ridges Riga Schist river rocks sand sandstone schist sections sedimentary sediments sheet Silurian slope specimens strata streams structure surface terrace Tertiary theory thickness tion unconformity upper valley volcanic
Popular passages
Page 175 - He was a fellow of the royal societies of London and Edinburgh, and a member of some other learned bodies.
Page 266 - The pieces of limestone are so markedly different from the calcareous bed enclosing them that they cannot be confounded with it. The rock fragments are of unequal distribution in the deposit, both laterally and vertically, sometimes composing almost half of it, and sometimes being almost entirely absent. They vary from a fraction of an inch to several inches in diameter and are indiscriminately mixed.
Page 404 - The geographic development of the eastern part of the Mississippi drainage system. Am. Geol., vol. xi, 1893, pp.
Page 611 - Agency of organisms; 2". Chemical precipitation; 3. By mechanical methods. It is the general opinion of geologists that limestone rocks are the result almost entirely of the consolidation of lime removed from the sea water through the agency of life, and that they consist of the remains of foraminifera, crinoids, corals, etc., or their fragments, embedded in a more or less crystalline matrix resulting from subsequent alteration of the original deposits. This, however, has been seriously questioned....
Page 201 - The Crocodilian Remains found in the Elgin Sandstones, with remarks on the Ichnites of Cummingstone.
Page 432 - The non-feldspathic intrusive rocks of Maryland and the course of their alteration.
Page 609 - I obtain 113 tons as the total amount of matter in solution discharged into the Atlantic basin per annum from each square mile of area drained into it. Of this 49 tons consist of carbonate of lime and 5.5 tons of sulphate and phosphate of lime.4 Mechanical sediments.
Page 409 - Price 10 cents. 65. Stratigraphy of the Bituminous Coal Field of Pennsylvania, Ohio, and West Virginia, by Israel C. White. 1891. 8". 212pp. 11 pi. Price 20 cents. 66. On a Group of Volcanic Rocks from the Tewan Mountains, New Mexico, and on the occurrence of Primary Quartz in certain Basalts, by Joseph Paxson Iddings.
Page 607 - Our knowledge of the conditions north of the 55th parallel is limited by the want of accurate geologic data. If Cambrian and Carboniferous rocks were not deposited in the Mackenzie river basin and also on the eastern side of the area now covered by Cretaceous strata, the inference is that during Cambrian and Carboniferous time there was a land area to the east and north of the northern Cordilleran sea that may have been tributary to the latter.
Page 625 - It is correlated with the Bow River series, which contains, in the upper portion, the lower Cambrian fauna. The presence of these calcareous beds indicates a slower rate of deposition than we have estimated for the lower portion of the Cambrian...