Thesis (M.S.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 11, 2009) Includes bibliographical references (p. 85-87).

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.

Sediments referred to the Trias outcrop at intervals over a distance of 105 miles (157 km) along the northwestern seaboard of Scotland. A detailed description is given of the field occurrences and successions, and the stratigraphy revised. Important rod sediments in Westor Ross, previously mapped as Trias, are shown to be Torridonian and their significance is discussed. The Trias is very variable in thickness ranging from negligible to over 300 m (1000 ft). Lithological units show rapid lateral variation, and it is impossible to draw detailed comparisons between successions in different areas. The sediments mainly consist of conglomerates and sandstones which are compared of materials derived from formations, known in the area at the present time. The study of textures and sedimentary structures shows that the sediments are fluviatile. Piedmont deposits and sediments which accumulated in an environment intermediate between piedmont and valley-flat are common true valley-flat deposits also occur, represented by thin fine-grained said-stones and siltstones, Concretionary limestones occur throughout the area, except in one locality, find are interpreted as pedocals. The sediments probably, accumulated in a series of partially isolated basins. Sedimentation was influenced early on by a chain of upland area consisting of n sequence, of Torridonian and Cambro-Ordovician sediments which extended from Loch Broom to Iona, west of the present outcrop of the Hoine Thrust. Source areas to the east became dominant later. The climate was probably hot and semi-arid, with seasonal rainfall.

This study establishes the stratigraphic framework and conodont biostratigraphy of Lower Paleozoic strata of the Northern Canadian Cordilleran Miogeocline, which document a non-passive tectonic evolution of the rifted margin of Laurentia. Only a few reconnaissance stratigraphic studies have been conducted previously in the study area. Nine key sections span an east-west transect from the Macdonald Platform to the Kechika Trough (platform-miogeocline-basin) and 3 key sections comprise a transect across the parautochthonous Cassiar Terrane. Over 12 000 m of strata from the Kechika and Skoki formations and Road River Group in northeastern British Columbia were measured and described, from which a total of 405 conodont samples (4-5 kg each) were taken. A total of 39 526 conodonts have been used to refine the Upper Cambrian to Lower Silurian conodont biostratigraphy across the transect. The stratigraphy is revised to divide the Kechika Formation (late Cambrian to early Arenig in age) into 5 formal members: Lloyd George, Quentin, Grey Peak. Haworth and Mount Sheffield members. The Skoki Formation (early to late Arenig in age) comprises 3 new formal members defined as: Sikanni Chief. Keily and Redfern members. The Road River Group is divided into 3 new formations: Ospika (early Arenig to Llanvim in age), Pesika (Lower Silurian in age) and Kwadacha (formerly the Silurian Siltstone). The Ospika Formation is further subdivided into 5 formal members: Cloudmaker, Finlay Limestone, Chesterfield, Finbow Shale and Ware. Conodonts of Late Cambrian to Early Silurian age are described taxonomically from the Kechika, Skoki, Ospika and Pesika formations across the transect. A total of 39 526 identifiable conodonts recovered from 142 productive samples indicate high species diversity and abundance in shallow water facies and less diversity and abundance with in deeper water facies. Elements are moderately to well preserved, typically with a colour alteration index (CAl) of 3-5. A total of 197 species, representing 73 genera are identified and illustrated among which 6 new genera and 39 new species are described. Fifteen of the 39 new species had too little material and were described in open nomenclature. The new genera are Graciloconus, Kallidontus, Planusodus and 3 new genera (A, B, C) treated in open nomenclature. The new species are Acodus kechikaensis n. sp., A. quentinensis n. sp., A. warenesis n. sp., Cordylodus delicatus n. sp., Colaptoconus greypeakensis n. sp., ?Diaphorodus n. sp., Drepanoistodus minutus n. sp., Graciloconus concinnus n. gen. n. sp., Kallidontus serratus n. gen. n. sp., K. nodosus n. gen. n. sp., K. princeps n. gen. n. sp., Laurentoscandodus sinuosus n. sp., Macerodus cristatus n. sp., M lunatus n. sp., Microzarkodina n. sp., Oepikodus n. sp., Oistodus n. sp., Paroistodus n. sp., Planusodus gradus n. gen. n. sp., ?Prioniodus n. sp., Protoprioniodus n. sp., Rossodus kwadachaensis n. sp., R. muskwaensis n. sp., R. sheffieldensis n. sp.. R. subtilis n. sp., Scolopodus amplus n. sp., Striatodontus strigatus n. sp., Triangulodus akiensis n. sp., Tricostatus infundibulum n. sp., T. terilinguis n. sp., 3 unnamed new genera and 3 new species and 5 new species of Drepanoistodus (A, B. C, D, E). The conodont zonation for Upper Cambrian to Lower Silurian strata is refined, using Sections 4, 5, 13 and Grey Peak as reference sections. It allows close dating of stratigraphic boundaries. The oldest zones in the Kechika are cosmopolitan and include the Eoconodontus Zone (upper Cambrian), Cordylodus proavus and Cordylodus lindstromi zones (uppermost Cambrian) and lapetognathus Zone (base of Tremadoc). Ten higher zones are recognized and redefined for shallow water platform facies containing faunas of the Midcontinent Realm. Four of these are new (Polycostatus falsioneotensis, Rossodus tenuis, Scolopodus subrex and Acodus emanualensis zones) and 10 new subzones are established. Those for the Kechika Formation include, in ascending order, the Polycostatus falsioneotensis Zone (lower Tremadoc). Rossodus tenuis Zone (lower Tremadoc); Rossodus manitouensis Zone with R. muskwaenesis and R. sheffieldensis subzones (middle Tremadoc), Low diversity interval (upper Tremadoc), Scolopodus subrex Zone with Graciloconus concinnus and Colaptoconus bolites subzones (lower Arenig) and Acodus kechikaensis Zone with Kallidontus serratus. Diaphorodus russoi and Kallidontus nodosus subzones (lower Arenig). Those for the Skoki Formation include the Oepikodus communis Zone with Tropodus sweeti, Bergstroemognathus extensus and Juanognathus variabilis subzones (middle Arenig). The O. communis Zone spans the Kechika-Skoki boundary and the uppermost Kechika lies within the lowermost part of the O. communis zone underlying the T. sweeti Subzone. The Skoki Formation also contains the Jumudontus gananda Zone (middle Arenig) and Tripodus laevis Zone (upper Arenig). The Phragmodus undatus Zone (Upper Ordovician) lies within the Road River Group in the Cassiar Terrane. Thirteen deep water zones are recognized for basinal facies containing faunas of predominantly the North Atlantic Realm. Five new zones are established (Drepanoistodus nowlani, Acodus deltatus, Paracordylodus gracilis, Paroistodus horridus and Dzikodus tableheadensis zones) and one new subzone within the P. gracilis Zone is proposed. Those within the Kechika Formation include Cordylodus angulatus Zone (lower Tremadoc), Paltodus deltifer Zone (middle Tremadoc), Drepanoistodus nowlani Zone (middle Tremadoc), Acodus deltatus Zone, (middle Tremadoc), Paroistodus proteus Zone (upper Tremadoc), Paracordylodus gracilis Zone with Oelandodus elongatus Subzone (upper Tremadoc) and Prioniodus elegans Zone (base of Arenig). Those within the Skoki and Ospika formations include Oepikodus evae Zone (Skoki Formation, middle Arenig), Paroistodus originalis Zone (Skoki and Ospika formations, upper Arenig), Paroistodus horridus and Dzikodus tableheadensis zones (both within the Ospika Formation, lower Llanvim). The Amorphognathus tvaerensis Zone lies within the Road River of the Cassiar Terrane (Upper Ordovician). The Distomodus staurognathoides Zone lies within the Pesika Formation (middle Llandovery). The conodont faunas therefore provide detailed temporal constraints for the stratigraphic framework. Some evolutionary remarks are made for selected species involved in radiations, especially in the Tremadoc and Arenig, that are useful in further refining the standard Midcontinent Realm zonation. The Midcontinent Realm conodont faunas are used for regional correlations within North America and those of the Atlantic Realm provide calibration on an interregional scale, for example, with Baltica. / Graduate

The distribution of Archean Nickel sulphide deposits reflects tectonic controls operating during the evolution of the granitoid greenstone terrains. Important deposits of komatiitic-affinity are concentrated within, and adjacent to, younger (∼2.7 Ga), rift-related greenstone belts (e.g. Canada, Western Australia and Zimababwe). Two important classes of Archean Nickel sulphide deposits exist, formerly known as "Dunitic" and "Peridotitic", these are now referred to as Group I and Group II deposits, based on their characteristic structure and composition. Mineralization varies from massive and matrix to disseminated, and is nearly always concentrated at the base of the host unit. Primary ores have a relatively simple mineralogy, dominated by pyrrhotite-pentlandite-pyrite, and to a lesser degree millerite. Metamorphic grades tend to range from prehnite-pumpellyite facies through to lower and upper amphibolite facies. Genesis of Group I and II deposits is explained by the eruption of komatiites into rift-phase greenstone belts, as channelized flows, which assimilated variable amounts of footwall rocks during emplacement. Sulphide saturation was dependent on the mode of emplacement and, the amount of sulphidic sediments that became assimilated prior to crystallization. This possibly accounts for variations in ore tenor. The Six Mile Deposit (SMD) in Western Australia, is an adcumulate body of the Group IIB-type, exhibiting disseminated mineralization. The ore has been "upgraded" due to hydration and serpentinization. A profound weathering sequence exists, which was subsequently utilized during initial exploration. Exploration techniques has been focused on Western Australia, as it is here that the most innovative ideas have emerged.

No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on December 28, 2007) Includes bibliographical references.

The Lower Mississippian Lodgepole/lower Madison Formations (20-225 m thick) developed along a broad (>700 km) stormdominated cratonic ramp. Three types of shallowing-upward cycles (5th order) are recognized across the ramp-to-basin transition. Peritidal cycles consist of very shallow subtidal facies overlain by algal-laminated tidal flat deposits, which are rarely capped by paleosol/breccia layers. Shallow subtidal cycles consist of stacked ooid grainstone shoal deposits or deeper subtidal facies overlain by ooid-skeletal grainstone caps. Deep subtidal cycles occur along the outer ramp and ramp-slope and consist of sub-storm wave base limestone-argillite, overlain by graded limestone, and are capped by storm-deposited skeletal-ooid grainstone. They pass downslope into rhythmically interbedded limestone and argillite with local deepwater mud mounds; no shallowing-upward cycles occur within the ramp-slope facies. Average cycle periods calculated along the outer ramp range from 30-110 k.y. The cycles likely formed in response to 5th order (20-100 k.y.) sea level oscillations. The cycles are stacked to form three 3rd to 4th order depositional sequences which are defined by regional transgressive-regressive facies trends. The ramp margin wedge (RMW) developed during long-term sea level fall lowstand conditions and consists of cyclic crinoidal bank and oolitic shoal facies which pass downdip into deep subtidal cycles. The transgressive systems tract (TST),which onlapped the ramp during long-term sea level rise, includes thick deep and shallow subtidal cycles; peritidal cycles are restricted to the inner ramp. The highstand systems tract (HST) developed during long-term sea level highstand and fall, and along the ramp is composed of early HST shallow subtidal cycles which are overlain by late HST peritidal cycles; shallow through deep subtidal cycles composed the HST along the ramp-slope. / Ph. D.

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