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Conodont paleontology of the Permian Sabine Bay, Assistance and Trold Fiord Formations, Northern Ellesmere Island, Canadian Arctic ArchipelagoHenderson, Charles Murray January 1981 (has links)
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
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Diagenetic, thermal and provenance histories of the Permian lower Ecca Group based on two newly drilled boreholes in the western and eastern main Karoo Basin, South AfricaGeel, Claire 21 January 2021 (has links)
Fine-grained sedimentary rocks of the Lower Permian lower Ecca Group in the Main Karoo Basin (MKB) in southern Africa have been identified to form a possible unconventional hydrocarbon reservoir, the gas potential of which is still relatively unknown. The lower Ecca Group is comprised of flysch-like successions of the Prince Albert, Whitehill and Collingham formations, which were impacted by diagenesis as well as contact and regional and metamorphism. Studies of fine-grained sedimentary rocks are notoriously complex as mechanical breakdown and diagenesis result in mineralogical changes and loss of source rock information. Therefore, a variety of analytical techniques are required for their thorough investigation. In this study, we analyse Permian rocks from two boreholes (KZF-1 and KWV-1) that were drilled ~ 830 km apart in the western and eastern MKB, respectively, and compare their composition, thermal maturity and petrophysical characteristics to better assess the hydrocarbon potential of the lower Ecca Group. In addition, whole rock geochemistry is used to reconstruct the palaeo-environment and provenance settings. Lastly, we investigate the influence of shale composition, porosity, well pressure and temperatures on their geomechanical properties such as compressive strength and elastic moduli. Sedimentary rocks in both boreholes were affected by burial and regional metamorphism (linked to orogenic events), but the sedimentary rocks in BH KWV-1 were also altered by contact metamorphism due to dolerite intrusions in the Early Jurassic. Major mineralogical differences between the boreholes include: 1) Fesilicate (greenalite); carbonates (rhodochrosite and dolomite) and Mn nodules (birnessite) being found only in BH KZF-1; and 2) metamorphic minerals such as garnet, cordierite, staurolite being found only in BH KWV-1. The results show that these rocks are over mature as evidenced by the low quantity of free hydrocarbons (S1 peak; 0.02–0.06 mg/g) and potential to release hydrocarbons (S2 peak; 0.06– 0.14 mg/g) and low hydrogen index (HI) values (2.40–167 mg HC/g TOC) from Rock Eval pyrolysis accompanied with high vitrinite/bitumen reflectance (BH KZF-1 is VRo= 4 and BH KWV-1 is BRo= 5). The total organic carbon (TOC) content is the highest in the Whitehill Formation in both boreholes (BH KZF-1: 5.17 wt%; BH KWV-1: 4.87 wt%). Burial diagenesis significantly reduced interparticle porosity and most of the measurable porosity comes from intraparticle nano-pores confined to organic matter v and dolomite. Meso- and macro-porosity are limited to phyllosilicates, pyrite framboids and microfractures. The Chemical Index of Alteration (CIA) is highest for the Prince Albert Formation (72– 78) as the palaeo-environment changed from an ice-house to a green-house, postglacial period in southern Gondwana. Enrichment of trace elements in BH KZF-1 and BH KWV-1 are in order: Mn > Ba > Zn > Co > Cu > V > Rb > Cr > Ni; and for BH KWV-1: Mo > Ba > Cu > Zn > Mn > V > Co > Cr > Rb > Ni. Geochemical proxies used in determining levels of anoxia were: V/Cr, V(V+Ni), Ni/Co and Fe-S-TOC plots. Salinity was deduced using Rb/K ratios and with identification of potential benthic foraminifera and minerals such as apatite, birnessite and phosphate nodules, which are assumed to be syn-sedimentary in origin. Overall, the geochemical results indicate that the depositional conditions fluctuated with respect to anoxia, salinity levels, and that while the sedimentation rates were low and the bio-productivity level was high, at least episodically. Provenance was investigated using Discriminant Function Diagrams, Principle Component Analysis Results (PCA), Zr/Ti ratios and the Index of Compositional Variability (ICV). Results indicate that the Prince Albert and Whitehill formations in the western MKB comprises sediment that was mostly sourced from the Cambrian to Late Carboniferous Cape Granite Suite, Cape Supergroup, the Dwyka Group and possibly the Precambrian Kango Group (Saldania Belt) and/or the Namaqua-Natal Belt. The Prince Albert and Whitehill formations in the eastern MKB have a mafic signature, indicating that these sediments may have been derived from the PermoCarboniferous Dwyka Group, Precambrian Kaapvaal Craton, Natal Belt (Tugela Terrane), Natal Group and the Pan-African Mozambique and Maud Belts. The mudstone and wackes in the Collingham Formation were mostly sourced from the quartz-arenites and granites that were most likely associated with the Cape Fold Belt, the orogen immediately adjacent to and largely coeval with the MKB. Geomechanical results from BH KZF-1 show that the lower Ecca Group has a high proportion (~ 50–70 vol%) of mechanically strong minerals (e.g., quartz, feldspar, pyrite), ~ 30–50 vol% weak minerals (e.g., clay, organic matter) and up to ~ 0–50 vol%, highly variable, intermediate components (e.g., carbonates). Constant strain rate deformation experiments (T ≤ 100 °C; p ≤ 50 MPa) and compressional tests performed perpendicular and parallel to bedding show that the Prince Albert Formation is the strongest and most brittle followed by the Collingham Formation and then the Whitehill Formation. Triaxial compressive strength as well as static Young's vi moduli increased with increasing hard minerals and decreased with increasing mechanically weak minerals and porosity. On comparison with European and American shales, the shales in the lower Ecca Group are geomechanically stronger and more brittle, and thus may allow for fracture propagation without rock breakdown under pressure. The lower Ecca Group varies from the western to the eastern MKB in mineralogy, thermal maturity, palaeo-depositional environment and provenance. These observations directly challenge the previous assumptions that these black shales were deposited under predominantly anoxic conditions. Indeed, during deposition, the levels of anoxia appear to have been inconsistent across the MKB and were likely dependent on the changing primary bio-productivity levels, sedimentation rates and basin morphology. Neither borehole contained significant gas, likely due to degasification by dolerite intrusions in the Early Jurassic and structural deformation during syn- and post-Karoo times. In summary, this study quantitatively confirms that the lower Ecca Group has the potential to be an easily frackable, unconventional shale gas reservoir. However, this study also attests to the compositional and geomechanical complexity of these Karoo rocks, and this inevitably translates to a gas potential that is expected to vary significantly across the basin.
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Detrital Zircon Analysis of Permian Victoria Group Sandstones, Transantarctic Mountains, AntarcticaHulett, Sam Rw January 2012 (has links)
No description available.
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Applications of Canonical Correlation in GeologyLee, Pei 05 1900 (has links)
<p> The theory of canonical correlation analysis has been combined with that of trend surface analysis in order to construct a multivariate trend surface which is called a canonical trend surface. </p> <p> A canonical trend surface is a parsimonious summarization of areal variations of a set of geological variates. This trend has a property of maximum correlation between variates and geographic coordinates. It does not show the absolute value of each variate, but it shows the nature of the variation of a linear combination of the variates. The Permian system in western Kansas and eastern Colorado was studied as a numerical example to illustrate the general procedures in solving practical problems and also to demonstrate the validity of this technique. By use of this type of trend it is possible to reveal the underlying pattern of geographic variation common to a set of variates. </p> <p> Other applications of canonical correlation analysis in geology have been explained with illustrative geological examples, namely: the relationships between two sets of variates, matching two factor patterns, Q-technique canonical correlation, and discriminatory analysis. </p> <p> Comparison of canonical correlation analysis and principal factor solution in factor analysis suggests that factor analysis may be more appropriate for suggesting interrelationships among variables, while canonical correlation analysis may be a suitable tool for prediction problems. </p> <p> FORTRAN IV programs for these computations are listed in appendices with instructions for using them. </p> / Thesis / Doctor of Philosophy (PhD)
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Carbon and strontium isotope stratigraphy of the Permian from Nevada and China: Implications from an icehouse to greenhouse transitionTierney, Kate Elizabeth 25 August 2010 (has links)
No description available.
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Depositional environment and taphonomy of some fossil vertebrate occurrences in Lower Permian redbeds in Archer County, TexasSander, Paul Martin 04 February 2013 (has links)
The Lower Permian Admiral Formation redbeds in north-central Texas are famous for their well-studied vertebrate fauna. Taphonomical and paleoecological aspects, however, are inadequately understood. The prerequisite for taphonomical interpretations is an analysis of the depositional environments. Low relief and low regional dip expose extensive paleoslopes in western Archer County. Three major depositional systems may be recognized: a fine-grained meanderbelt, a low sinuosity fine-grained fluvial system, and a tidal flat. The small scale of the sedimentation (average sandstone thickness 1. 5 m) is remarkable. Four types of vertebrate occurrences can be distinguished: Type 1: Mass death bonebeds are situated in a floodbasin facies comprised of gray and red mudstones with abundant Psaronius roots (a swamp-dwelling tree fern) which is associated with the fluvial systems. Such basins were covered by a dense swamp forest with a high diversity of vertebrates. This type is exemplified by the Geraldine Bonebed, which has yielded at least 45 partly articulated skeletons representing 4 genera of tetrapods, and remains of another 8 vertebrate taxa. The bones were found on a layer of fern, seed fern, and conifer foliage and wood. This occurrence was formed by a single catastrophic event, possibly a forest fire, which drove the animals of the swamp forest into a pond, where they died of suffocation and were concentrated into a bonebed by physical processes (wind). Type 2: Lag bonebeds, situated on the landward margin of tidal flat environments, are represented by the Rattlesnake Canyon Bonebed which consists mainly of a calcareous concretion conglomerate, which contains fragmentary bone, serpulid worm colonies (brackish water!), and calamitelean wood. The diversity of forms represented by articulated material is low. The ubiquitous predator Dimetrodon and an amphibian, Trimerorachis, which tolerates brackish water, are common. This type was deposited as lag in a storm washover deposit. Type 3: Ponds (abandoned channels, etc.) which contained a fauna dominated by aquatic forms (the fishes Xenacanthus and Ectosteorachis, and the amphibian Archeria) were gradually filled by fine-grained sediment and organic debris (vertebrates, plants). These oxbow lakes were probably rimmed by stands of Calamites. Four examples are described. Type 4: Single, complete skeletons examplified here by Diadectes are occasionally found in red floodplain mudstones. / text
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A stratigraphic study of the insoluble residues of the Council Grove group limestones of the Manhattan, Kansas, areaParish, Kenneth Leroy. January 1952 (has links)
Call number: LD2668 .T4 1952 P35 / Master of Science
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Depositional environments of the Wood Siding Formation and the Onaga Shale (Pennsylvanian-Permian) in northeast KansasBisby, Curtis G. January 1986 (has links)
Call number: LD2668 .T4 1986 B57 / Master of Science / Geology
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Petrology and stratigraphy of the Epitaph Dolomite (Permian) in the Tombstone Hills, Cochise County, ArizonaPatch, Susan, 1945- January 1969 (has links)
No description available.
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Geologia e paleontologia das formações Tatuí e Irati no centro-leste do Estado de São PauloChahud, Artur 17 November 2011 (has links)
A área de ocorrência das formações Tatuí e Irati, na região centro-leste do Estado de São Paulo, entre as cidades de Leme e Rio das Pedras é objeto desta pesquisa. São detalhadas as ocorrências destas duas formações, através de seções estratigráficas, caracterizando e analisando as sucessões de litotipos, conteúdo fossilífero, tafonomia dos fósseis, além de enfocar hipóteses paleoecológicas e paleoambientais. Na FormaçãoTatuí foram identificadas quatro fácies, a inferior de arenitos finos e paleoambiente incerto, duas refletindo contexto não marinho e a de topo com influência marinha. As duas fácies do contexto predominantemente não marinho são respectivamente siltitos arenosos com fósseis de água doce e arenitos grossos ou conglomeráticos, fácies Ibicatu, localmente com lenhos. A fácies de topo é caracterizada por depósitos de arenitos finos, ocasionalmente com grandes estratificações cruzadas, estratificações \"hummockies\", apropriado para um grande corpo d\'água salino. O conteúdo fóssil da Formação Tatuí inclui três tipos de icnofósseis em três fácies diferentes (fácies basal do estudo, Ibicatu, e no topo), grandes caules vegetais (pteridófitas e espermatófitas) na fácies Ibicatu, crustáceos (conchostráceos e fragmentos indeterminados) ocorrem na fácies síltica, escamas, dentes e partes ósseas de peixes ósseos na fácies siltica e topo da Formação Tatuí. O Membro Taquaral é reconhecido por duas fácies e dois paleoambientes de salinidade variável. A fácies basal, composta de arenitos finos a conglomeráticos, granulometria irregular horizontal e verticalmente e com ictiofósseis, é interpretada como depositada em ambiente raso dominado por ondas. A segunda fácies, folhelhos sílticos, é típica de paleoambientes mais calmos, provavelmente com menor salinidade. Os fósseis da base arenosa do Membro Taquaral são peixes, representados por Chondrichthyes sob a forma de dentes cladodontes, espinhos de Euselachii (Amelacanthuse Iratiacanthus), espinhos Ctenacanthiformes (Sphenacanthus sanpauloensis eS. sp.), dentes de Xenacanthiformes, Diplodoselachidae (Taquaralodus albuquerquei) e Xenacanthidae, dentes de Orodontiformes, (Orodus ipeunaensis), Petalodontiformes (Itapyrodus punctatus eI. sp.) e Holocephali indeterminados. A fauna de Osteichthyes é a mais abundante em número de espécimes, sendo composta, predominatemente, de dentes e escamas paleoniscóides, raras escamas de Coelacanthimorpha, partes ósseas e dentes labirintodontes, estes atribuídos a Osteolepiformes e a tetrápodes Temnospondyli. Os fósseis estão normalmente dispersos e desarticulados e os elementos ósseos fragmentados e desgastados. O conteúdo fóssil da fácies folhelho síltico do Membro Taquaral é raro, os mais comuns são crustáceos, principalmente do gênero Clarkecaris, e restos muito fragmentados de Coelacanthimorpha e Palaeonisciformes. / The following Paraná Basin, Late Paleozoic lithoestratigraphic units, the upper part of the Tatuí Formation, located under the lower partof the Irati Formation, Taquaral Member are cropping out at center-eastern State of São Paulo, Brazil, between Rio das Pedras and Leme. The lithologies, fossil contents and taphonomy ofthese units are studied through stratigraphic sections, allowing the formulations of paleoecological and paleoenvironmental hypothesis. Four facies were recognized at the top of the Tatuí Formation stratigraphic sections which were interpreted as following; the basal an uncertain paleoenvironment of deposition, two paleoenvironmental contexts; mostly continental and one under deposits marine influence. The two facies interpreted as mostly continental are respectively, sandy-siltstones facies with freshwater fossils and coarse to conglomeratic sandstone, Ibicatu facies, locally with log plants. The top facies, interpreted as under a marine influence, is characterized by deposits of fine sandstones, occasionally with large cross beds, hummockies, and, locally, tidal deposits, suited for a large body, of saline water. The fossil content of Tatui Formation include three kinds of trace fossils in three different facies (basal, Ibicatu and top respectively), large stem plants (Pterydophyta and Spermatophyta) in the Ibicatu deposit, with indeterminated fragments of crustaceans and conchostraceans, found out in the siltstone facies and scales, teeth and bone pieces, found out in siltstone and of the top facies. Two facies were recognized at the Taquaral Member. The basal are fine to conglomeratic sandstone with irregularly grain size both horizontal and vertically, with ichthyofossils. Itis interpreted as laid down in a salty shallow water dominated by waves. The second are silty shale laid down in low saline water. The fossils of the sandy facies are Chondrichthyes: cladodontes teeth, Euselachii finspines (Amelacanthus and Iratiacanthus santamariaensis), Ctenacanthiformes finspines (Sphenacanthus sanpauloensisand S.sp.), Xenacanthiformes teeth, Diplodoselachidae (Taquarodus albuquerquei) and Xenacanthidae, Orodontiformes: Orodus ipeunaensis, Petalodontiformes (Itapyrodus punctatus andI. sp.) and undetermined Holocephali. The fauna of Osteichthyes, the most abundant in number of specimens are predominantly paleoniscoid teeth and scales, rare Coelacanthimorpha scales, labyrinthodonts bones and teeth, assigned to Osteolepiformes and tetrapods Temnospondyli. The fossils are usually scattered, disorganized, fragmented and worn. The fossil content of the Taquaral silty-shale facies is meager, the most common are crustaceans, mainly of the genus Clarkecaris, and very fragmented remains of Coelacanthimorpha and Palaeonisciformes.
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