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The Devonian rocks considered here, outcrop over a distance of 100 kms., along the northern side of a strip of water, known as the Trondheimsled, near Trondheim, Norway. Since time did not permit complete examination, two areas were selected for detailed study: 1) the western end of the outcrop on the large island of Hitra, where fossils suggesting an Upper Silurian or Downtonian age had been found; and 2) the outcrops on the island complex south of the neighbouring island of Smola. The precise age of these beds was unknown. An attempt was made to establish the stratigraphy of both areas, and to deduce the environment of deposition, the nature of the source area, and the direction of derivation of the sediments. Hitra. The succession (1055 m. thick) has been divided into a number of stratigraphical units on the basis of lithology. Much of it is made up of thick sandstones, often pebbly or conglomeratic, and alternating sandstone/siltstone sequences. Study of the sedimentary structures and size distributions of these sequences suggests that the cycles have been produced in an inshore estuarine environment, as a result of the lateral migration of channels. The petrography of the sandstones and conglomerates shown thot the sediments were derived from a source area composed mainly of plutonic rocks, while current direction analysis shows derivation from the northwest. Smola: The Smola Series, composed of 3745 m. of conglomerate, has been divided petrographically into four units. The oldest conglomerate lies unconformably on the beds below and is made up of large boulders of locally derived material. The younger conglomerates are composed of abundant pebbles of green sandstone (possibly the Ordovician Hovin Sandstone), and various igneous and metamorphic PEBBLES which are difficult to match with rocks now exposed in Norway. The sediments wore derived from the north and were probably deposited in a piedmont environment. Relative age of the Hitra and Smola series Consideration of the stratigraphical, petrographical, and sedimentological evidence shows that the Hitra sediments are older than those Smola. A reconsideration of the paleontological evidence suggests that the Hitra beds could be of Upper Welockian or early Ludlovian age, while the Smola beds are probably Lower or Middle Devonian.

Lower and Middle Devonian strata crop out on the former stable carbonate platform that existed in the Quinn Canyon Range, through the carbonate shelf edge in the Pancake Range, to the carbonate slope and outer-shelf basin in the Reveille Range. The strata of the Reveille Range record a transition from deposition on the carbonate platform in the Lower Devonian, to deposition at the carbonate platform margin, to deposition in the outer-shelf basin in the Middle Devonian. Conodonts collected from the base of the Sevy Dolomite yield a kindlei-Zone age, an indication that the Sevy Dolomite is younger than previously recognized. Throughout the Lower and Middle Devonian, carbonate strata of the Pancake Range and Quinn Canyon Range were deposited on the shallow carbonate platform. Conodonts collected from the base of the Lower Alternating Member of the Simonson Dolomite in the Quinn Canyon Range have a slightly older age (serotinus- to costatus Zone) than other eastern Nevada locations. The Lower Devonian Sevy Dolomite was deposited in a shallow carbonate subtidal through supratidal environment and is similar in outcrop throughout the ranges. Petrographic studies show that the samples are lithologically and diagenetically similar, indicating a similar intensity of dolomitization from the precursor calcareous mudstone. The Formation classifies as bioturbated mudstone and wackestone. The Middle Devonian Simonson Dolomite was deposited in shallow carbonate subtidal through supratidal environments. The Simonson Dolomite was affected by Milankovitch Cycles, glacioeustatic oscillations of sea level, producing a characteristic rhythmic bedding. The Middle Devonian Sadler Ranch Formation and Denay Limestone are lithologically and diagenetically different from the shallow water deposits of the Lone Mountain Dolomite, Sevy Dolomite, and Simonson Dolomite. The Sadler Ranch Formation and Denay Limestone were deposited at the carbonate platform edge and on the carbonate slope and outer-shelf basin, respectively. The Sadler Ranch Formation is dolomitized and may be classified as fossiliferous wackestone and mudstone. The Denay Limestone is not dolomitized and is classified as mudstone and fossiliferous grainstone and packstone. Dolomitization in the Paleozoic strata of Nevada is a secondary feature, an early diagenetic replacement of strata which were originally limestone. This replacement process was controlled by transgressions and regressions of the shoreline. Shallow carbonate platform deposits (shelfal and tidal-flat) are dolomitized, whereas deep water outer-shelf basin and slope deposits are not. / Graduation date: 1997

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The thesis represents a field and paleontological study of Devonian strata exposed in the Ram River Area west of Nordegg Alberta, and is intended to present information which will supplement data obtained from exploration drilling of the Great Plains basin. Certain structural phenomena are discussed in relation to the problems of the Rocky Mountain overthrust belt. It is concluded that overfolding in many cases preceeded thrust fault development, that modification of Lawson’s equation may be necessary in the consideration of low-angle thrust faults, and that the Eastern Ranges may have suffered less displacement than those of the western Rockies. The principles of regional and interregional correlation are discussed with a view to evaluation of the criteria and limitations of biostratigraphic correlation. Previous stratigraphic work is reviewed, and detailed descriptions of the Flume, Perdrix, and Cheviot Formations are submitted. The Perdrix Formation is recognized as being divisible into two new members, the Blackface and Whitegoat Members. Faunal description, revision, and illustration of five species of corals and thirty species of brachiopods constitute the main part of the work. Revision shows that Leiorhynchus albertense Warren is referable to Calvinaria, and that Bellerophon neleus Hall and Whitfield is referable to Aglaeoglypta. One variety, Calvinaria albertense var. plicata is recognized as new. / Arts, Faculty of / Geography, Department of / Graduate

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No description available.