Thesis (M.Sc.) -- Memorial University of Newfoundland, 1987. / Typescript. Bibliography: leaves 135-155. Also available online.

Thesis (M.Sc.)--Memorial University of Newfoundland. / Typescript. Bibliography: leaves 344-362. Also available online.

Conodontes são microfósseis potencialmente úteis para bioestratigrafia e em reconstruções paleoecológicas de rochas sedimentares paleozóicas e do Triássico. Desta forma, este estudo apresenta a classificação taxonômica e o estabelecimento das condições biocronoestratigráficas e paleoecológicas nas quais estes organismos viveram, bem como uma revisão do estágio atual do conhecimento a respeito dos conodontes e de seu aparelho alimentar. A seção analisada pertence à Formação Itaituba, Grupo Tapajós, Pensilvaniano da Bacia do Amazonas. A área de estudo localiza-se a Nordeste da cidade de Itaituba, às margens do Rio Tapajós, em um afloramento da Pedreira Calminas. A distribuição dos conodontes reconhecida define duas biozonas: uma Zona de Amplitude Diplognathodus orphanus e uma Zona de Concorrência Idiognathodus incurvus-Idiognathoides sinuatus. As espécies Diplognathodus coloradoensis, Diplognathodus orphanus e Idiognathodus incurvus formam uma associação tipicamente atokana. Baseando-se na associação descrita, a seção analisada foi definida como atokana. A espécie de melhor resolução bioestratigráfica é Diplognathodus orphanus, sendo sua distribuição restrita ao Atokano. O ambiente deposicional dominante na Bacia do Amazonas durante o Pensilvaniano é caracterizado por uma rampa carbonática rasa. Os depósitos estudados refletem uma sequência predominantemente regressiva, com a presença de gêneros de águas mais rasas, tais como Adetognathus, Diplognathodus e Ellisonia. A ocorrência de conodontes associados a braquiópodes, briozoários, crinóides e fragmentos de peixes sugere que estes estratos foram depositados em paleoambiente marinho raso, com energia de sedimentação baixa a moderada, em águas calmas, límpidas e quentes. No regime de flutuações de alta freqüência do nível do mar, os principais ambientes deposicionais eram laguna (submaré) e planície de maré (intermaré superior-supramaré inferior com tapetes microbiais). / Conodonts are useful microfossils for biostratigraphy and paleoecological reconstructions in Paleozoic and Triassic sedimentary rocks. This research aims to their taxonomic classification and to establish the biochronostratigraphic and paleoecological conditions in which these organisms lived. Furthermore, this study reviews the current knowledge about conodonts and their feeding apparatus. The section analyzed belongs to Itaituba Formation, Tapajos Group, Pennsylvanian of the Amazon Basin. The study area is located northeast of Itaituba city, on the banks of the Tapajós River, in an outcrop of Calminas Quarry. The distribution of conodonts recognized defined two biozones: Diplognathodus orphanus Amplitude Zone and Idiognathodus incurvus-Idiognathoides sinuatus Competition Zone. The species Diplognathodus coloradoensis, Diplognathodus orphanus and Idiognathodus incurvus are typically an Atokan association. Based on the association described, the section analyzed was defined as Atokan. The specie with better biostratigraphic resolution is Diplognathodus orphanus, because its distribution is restricted to the Atokan. The depositional environment prevailing in the Amazon Basin during the Pennsylvanian is characterized by a shallow carbonate ramp. The deposits studied reflect a predominantly regressive sequence, with the presence of shallow water genera, such as Adetognathus, Diplognathodus and Ellisonia. The occurrence of conodonts associated with brachiopods, bryozoans, crinoids and fish fragments suggests that these strata were deposited in a shallow marine environment, with low to moderate energy, in calm, clear and warm waters. In high frequency sea level fluctuations regime, the main depositional environments were lagoon (subtidal) and tidal flat (upper intertidal-lower supratidal with microbial mats).

Conodontes são microfósseis potencialmente úteis para bioestratigrafia e em reconstruções paleoecológicas de rochas sedimentares paleozóicas e do Triássico. Desta forma, este estudo apresenta a classificação taxonômica e o estabelecimento das condições biocronoestratigráficas e paleoecológicas nas quais estes organismos viveram, bem como uma revisão do estágio atual do conhecimento a respeito dos conodontes e de seu aparelho alimentar. A seção analisada pertence à Formação Itaituba, Grupo Tapajós, Pensilvaniano da Bacia do Amazonas. A área de estudo localiza-se a Nordeste da cidade de Itaituba, às margens do Rio Tapajós, em um afloramento da Pedreira Calminas. A distribuição dos conodontes reconhecida define duas biozonas: uma Zona de Amplitude Diplognathodus orphanus e uma Zona de Concorrência Idiognathodus incurvus-Idiognathoides sinuatus. As espécies Diplognathodus coloradoensis, Diplognathodus orphanus e Idiognathodus incurvus formam uma associação tipicamente atokana. Baseando-se na associação descrita, a seção analisada foi definida como atokana. A espécie de melhor resolução bioestratigráfica é Diplognathodus orphanus, sendo sua distribuição restrita ao Atokano. O ambiente deposicional dominante na Bacia do Amazonas durante o Pensilvaniano é caracterizado por uma rampa carbonática rasa. Os depósitos estudados refletem uma sequência predominantemente regressiva, com a presença de gêneros de águas mais rasas, tais como Adetognathus, Diplognathodus e Ellisonia. A ocorrência de conodontes associados a braquiópodes, briozoários, crinóides e fragmentos de peixes sugere que estes estratos foram depositados em paleoambiente marinho raso, com energia de sedimentação baixa a moderada, em águas calmas, límpidas e quentes. No regime de flutuações de alta freqüência do nível do mar, os principais ambientes deposicionais eram laguna (submaré) e planície de maré (intermaré superior-supramaré inferior com tapetes microbiais). / Conodonts are useful microfossils for biostratigraphy and paleoecological reconstructions in Paleozoic and Triassic sedimentary rocks. This research aims to their taxonomic classification and to establish the biochronostratigraphic and paleoecological conditions in which these organisms lived. Furthermore, this study reviews the current knowledge about conodonts and their feeding apparatus. The section analyzed belongs to Itaituba Formation, Tapajos Group, Pennsylvanian of the Amazon Basin. The study area is located northeast of Itaituba city, on the banks of the Tapajós River, in an outcrop of Calminas Quarry. The distribution of conodonts recognized defined two biozones: Diplognathodus orphanus Amplitude Zone and Idiognathodus incurvus-Idiognathoides sinuatus Competition Zone. The species Diplognathodus coloradoensis, Diplognathodus orphanus and Idiognathodus incurvus are typically an Atokan association. Based on the association described, the section analyzed was defined as Atokan. The specie with better biostratigraphic resolution is Diplognathodus orphanus, because its distribution is restricted to the Atokan. The depositional environment prevailing in the Amazon Basin during the Pennsylvanian is characterized by a shallow carbonate ramp. The deposits studied reflect a predominantly regressive sequence, with the presence of shallow water genera, such as Adetognathus, Diplognathodus and Ellisonia. The occurrence of conodonts associated with brachiopods, bryozoans, crinoids and fish fragments suggests that these strata were deposited in a shallow marine environment, with low to moderate energy, in calm, clear and warm waters. In high frequency sea level fluctuations regime, the main depositional environments were lagoon (subtidal) and tidal flat (upper intertidal-lower supratidal with microbial mats).

A succession of late Early through Medial Permian conodont faunas is documented for the first time from the calcareous, fine grained, quartzose sandstones of the Assistance and Trold Fiord Formations on northern Elles-mere Island, Northwest Territories. Of the taxa identified and described, one species and three subspecies are proposed as new. The taxa include, in chronological order: Neogondolella idahoensis subsp. indet., Neostrep-tognathodus prayi, Neogondolella idahoensis n.subsp. A, Anchignathodus minutus, Neogondolella serrata(?), N. n.sp. B, N. postserrata(?), N. bitteri n.subsp. C, and N. rosenkrantzi n.subsp. D. Numerous ramiform elements are also associated with Neogondolella idahoensis n.subsp. A. These elements may comprise part of a multielement Neogondolella apparatus or they may represent separate form species. In observation of their questionable status, a somewhat unsatisfactory dual taxonomy is proposed for these elements, and includes the following taxa: N. idahoensis n.subsp. A - Xanio-gnathus tortilis, N. idahoensis n.subsp. A - Ellisonia excavata, N. idahoensis n.subsp. A - Ellisonia tribulosa, and N. idahoensis n.subsp. A - Pri-oniodella decrescens. Statistical work on the abundant platform elements of N. idahoensis n.subsp. A provides evidence for minor 'evolutionary trends of increasing size and increasing number of denticles upsection. Comparison of these con-odonts with N. serrata.and N. postserrata from the Great Basin of SW USA suggests that the phylogenetic development of Permian Neogondolella followed an,, evolutionary path.more appropriate to punctuated equilibria than to phyletic gradualism. The conodont taxa indicate that the Assistance Formation is Upper Leonardian to Uppermost Roadian in age whereas the Trold Fiord Formation includes most of the Wordian.stage. These two formations have been separated into five subdivisions on the basis of both lithology. and the presence or absence of various biota 1 A sixth, subdivision is described for the Sabine Bay Formation which underlies the Assistance and where conodonts are apparently absent. Lithologic and biotic evidence (including trace fossils and mega- and microbiota) point to shallow, offshore marine conditions well within the photic zone and characterized by low energy and slow depositional rates, for most of the conodont bearing strata. A much thicker correlative section to the south represents, in large part, a delta front sequence. The Sabine Bay Formation, on the other hand, is composed of shoreface sandstones, possibly in a barrier island setting. The results of this research indicate that conodonts may be very promising for correlation of Permian strata in the Canadian Arctic Archipelago and for worldwide comparison. More work within the Sverdrup Basin, including both marginal and basinal sections , is necessary to provide a good biozonation of these marine Permian strata. The use of the abundant brachiopods in combination with the conodonts is probably the best way to resolve this zonation. The taxonomic.descriptions and subdivisions proposed herein should provide a foundation for future work. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Three named major cycles of marine transgression and regression (cyclothems) in the lower Cherokee Group are recognized from the Arkoma Basin margin in east-central Oklahoma across the northern Midcontinent shelf, on the basis of distinctive conodont morphotypes. The lowest of these (McCurtain) is characterized by Idiognathodus cf. praeobliquus and absence of I. obliquus and Idiognathoides. The middle cyclothem (Doneley) is the first major cyclothem to yield I. obliquus. The uppermost (Inola) yielded abundant Idiognathodus, Neognathodus and Idioprioniodus, and sparse Gondolella, and is characterized by large numbers of Idiognathodus podolskensis. All three contain large numbers of I. amplificus. At the base of the succession, the genus Idiognathoides in three cores from northeastern Kansas to south-central Iowa confirms the presence of Atokan strata in the Forest City Basin. The McCurtain cyclothem extends from Oklahoma to the Forest City Basin in northeastern Kansas. The Doneley and Inola cyclothems extend from Oklahoma into Iowa. The Inola Limestone of Oklahoma is equivalent to the Hackberry Branch Limestone of western Missouri. The Bluejacket Coal of Oklahoma, at the base of the Inola cyclothem, is likely equivalent to Bluejacket A Coal of Kansas, Weir B or C coals in Missouri, and a middle Laddsdale coal in Iowa. The Rowe Coal of Oklahoma, Kansas, and Missouri, at the base of the Doneley cyclothem, is likely equivalent to the Cliffland Coal of Iowa. Inconsistent marine lithofacies in all three cyclothems suggest a complex depositional history on irregular surfaces.

No description available.

This study describes the biostratigrapaic distribution of Meramecian conodonts from three measured sections of the Greenbrier Limestone (Meramecian-Lower Chesterian), located in the Greendale and Hurricane Ridge Synclines of southwestern Virginia and southern West Virginia. The Little Valley Formation, Hillsdale Limestone and lower portions of the "Denmar-Gasper" and "Ste. Genevieve" Formations, consisting of rocks deposited in a variety of shallow carbonate-ramp environments, were investigated. Two new multielement conodont apparatuses were recognized: Kladognathus sp. A and Hindeognathus ("Apatognathus") laevipostica. Elements of Kladognathus sp. A are morphologically distinct from homologous elements of the K. levis-K. tenuis group. Evolutionary change from K. levis to K. tenuis is marked by slight Sa and Sb element changes, and the addition of an X element, DE Lambdagnathus fragilidens. Species of Kladognathus are promising Meramecian biostratigraphic markers. Also recognized in this study are species of: Cavusgqnathus, Gnathodus, Hindeodus, Idioprioniodus, Lochriea, Rhachistognathus, “Spathognathodus," Synprioniodina? and Taphrognathus. Meramecian formations in the study area can be correlated with the Mississippian stratotype (Illinois Basin) based on the following zones: Taphrognathus varians - "Apatognathus," "A." scalenus - Cavusgnathus aad Gnathodus bilineatus - Cavusgnathus charactus. Southward thickening of the "A." scalenus zone from the Hurricane Ridge Syncline (11 m) to the Greendale Syncline (180-200 m) reflects higher rates of sedimentation and subsidence in the depositional area of the latter. In addition, thinness of the zone in the Hurricane Ridge Syncline may be due to a hiatus between this zone and the younger G. bilineatus zone. This hiatus is not indicated by conodont faunas from the Greendale Syncline, which preserves a more complete Meramecian biostratigraphic record. Conodont and litahologic evidence for a coeval hiatus exists in other areas of eastern North America: the Illinois Basin stratotype, eastern Kentucky, Southern Ohio and eastern Tennessee. / Master of Science

Biostratigraphic study of the Late Silurian-Early Devonian strata of western Virginia reveals the presence of at least three potentially useful multielement conodont apparatuses. Two multielement species of the genus Ozarkodina may prove to be useful in determining the boundary between the Silurian and Devonian Systems in the Appalachian Basin. Currently, a single form species, Icriodus woschmidti woschmidti, which was found in the lowermost New Creek Limestone at Low Moor, Virginia, is used by previous agreement to denote the base of the Devonian system. In the absence of this standard paleontologic indicator, multielement species of the genus Ozarkodina aay be useful. Ozarkodina steinhornensis eosteinhornensis is identified from the Silurian Tonoloway Formation in the area of New Castle, Virginia. Ozarkodina steinhornensis remscheidensis, which is transitional to Oz. s. eosteinhornensis, has been identified in the overlying Late Silurian-Early Devonian Keyser Formation and Early Devonian New Creek Limestone near New Castle and Low Moor. Oz. s. remscheidensis, which is reported to occur first in the Gedinnian, has been suggested as a possible alternative indicator of lowest Devonian strata (Walliser, 1971). However, because of the transitional relationship of these two multielement species, abundant yields of conodonts are necessary to determine the first appearance of Oz. s. remscheidensis. Elements belonging to a third conodont apparatus, Delotaxis elegans, have been recovered from the Keyser and New Creek intervals at the same locations. Delotaxis elegans may ultimately prove to be a significant biostratigraphic marker with further study of these units. An overview of the Late Silurian-Early Devonian strata in Alleghany, Botetourt, Craig, and Roanoke Counties is developed to provide a regional perspective of this stratigraphic package and to illustrate significant biostratigraphic markers. Unconformities, wedge-outs, facies changes, and thickness variations are examined within the study area based on nine measured sections and a review of pertinent literature. Clastic units and quartzose carbonates within the Helderberg Group are discussed with regard to source area. / Master of Science

Devonian and Early Carboniferous marine clastic rocks of the Earn Group host several economically important stratiform massive sulphide and bedded barite deposits. Due to the chaotic sedimentation, considerable regional metamorphic overprint and, relative inaccessibility, little was known about the stratigraphy, the Late Devonian conodont fauna, or the age of the stratiform mineral deposits within the Earn Group. Conodont microfossils, however, are an excellent fauna for an Earn Group biostratigraphy program because of their ability to withstand both temperatures in excess of 400° C, and significant physical stress. With standard laboratory techniques conodonts were readily extracted from fine grain calcareous elastics and carbonate lenses within the Earn Group. The conodonts are described from three specific areas where the Earn Group is known to host stratiform barite and barite-lead-zinc mineral deposits: Macmillan Pass, Midway, and Gataga. As the majority of conodonts were diverse and well preserved platform elements of the genus Palmatolepis, the taxonomic studies focused on this genus; other genera including Ancyrodella, Icriodus, Klapperina, Mesotaxis, and Polygnathus were examined as part of the biostratigraphic/taxonomic studies. Previous to this study the widespread stratiform mineralization was dated as only Late Devonian. The conodont taxonomy and biostratigraphy in the Earn Group provide age constraints for duration and formation of the stratiform mineralization. The ability to tightly constrain the age of the stratiform mineralization adds to the knowledge of Earn Group deposition, the paleogeography of the Selwyn and Kechika Basins, and has implications for stratiform mineral exploration strategies in the Earn Group. On the basis of conodont faunal ages barite mineralization at MACMILLAN PASS apparently occurs as three different levels: 1) CATHY property - Eifelian to early Frasnian; 2) PETE, JEFF, GARY, and GHMS properties - middle to late Frasnian; 3) TEA property -Early Carboniferous. In addition, barite-lead-zinc mineralization at TOM and JASON properties likely occurs during middle to late Frasnian. In the GATAGA area barite and barite-lead-zinc mineralization have been recognized at several temporally distinct levels in the early to middle Famennian: 1) Lower rhomboidea Zone; 2) Lower marginifera Zone; 3) Upper marginifera Zone. Several other mineralized horizons are loosely constrained within the same interval. Within the MIDWAY area the stratiform barite mineralization at the EWEN and PERRY properties is of Early Carboniferous, Tournaisian age, and correlates broadly with the TEA barite in the Macmillan Pass area. In summary, events that produced stratiform barite-lead-zinc and barite mineralization in the Selwyn and Kechika Basins were not coeval. The Late Givetian and early Frasnian barite mineralization took place in the Macmillan Pass and southernmost Gataga areas. During the middle Frasnian barite and barite-lead zinc mineralization events occurred at Macmillan Pass. Several episodes of barite and/or barite-lead-zinc mineralization occurred in the Gataga area during the middle Famennian. The youngest barite mineralization events in the Earn Group took place in the Early Carboniferous, Tournaisian time at Macmillan Pass and Midway. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate