The chronostratigraphic correlation of the Silurian units in Iowa is complicated by complex carbonate depositional environments and poor biostratigraphic control. In this study, we integrate conodont biostratigraphic data with carbon isotope (δ 13Ccarb) chemostratigraphic data from the Blanding, Hopkinton, Scotch Grove, and LaPorte City formations of Iowa to provide a precise chronostratigraphic framework for regional and global correlation. Conodonts from the LaPorte City Formation of eastern Iowa (East-Central Iowa Basin) in the Garrison Core indicate an early to middle Telychian age for the formation. Conodonts diagnostic of the Pterospathodus eopennatus Superzone, Pterospathodus eopennatus ssp. nov. 2 Zone, and Pterospathodus amorphognathoides angulatus Zone were recovered, allowing for the first direct comparison of the stratigraphic ranges of conodont species from the North American Midcontinent and the Baltic basin. The morphology of Pseudolonchodina fluegeli ssp. n. Männik (2007) co-occurs with Pseudolonchodina fluegeli fluegeli sensu Männik (2007a) in the LaPorte City Formation and are not stratigraphically separated in Iowa as they are in the East Baltic. Wurmiella? polinclinata polinclinata ranges much lower in the East-Central Iowa Basin (Pt. eopennatus ssp. nov. 2 Zone) than the Baltic Basin, so it cannot be used as an index fossil diagnostic of the Pt. am. amorphognathoides Zone in global correlations. Three carbon isotope excursions were recovered from the Hopkinton and Scotch Grove formations. The late Aeronian (herein renamed “Farmers Creek”) carbon isotope excursion and a heretofore unrecorded carbon isotope excursion were recorded from the Hopkinton Formation in the SS-10 Core (Jones County). The Farmers Creek Excursion can be correlated to Johnson County, where it was recorded in the Hopkinton Formation by McAdams et al. (in prep). The Valgu excursion was recovered from the uppermost Hopkinton Formation through the overlying Buck Creek Quarry Member of the Scotch Grove Formation in the Garrison Core (Benton County). This excursion can be correlated to Johnson County, where it was recorded in the same formations. The integration of conodont biostratigraphic and carbon isotope chemostratigraphic data from the Silurian of Iowa allows for the first regional chronostratigraphic correlations at a resolution finer than stage level. The oxygen and carbon isotope values from the Garrison Core and the evidence for post-diagenetic karsting and fluid movement through the units may provide further evidence that the dolomitization process of the LaPorte City Formation was halted by the influx of meteoric phreatic water. This study shows the first high-resolution chronostratigraphic correlation of Silurian units in Iowa, and highlights the utility of integrated carbon isotope chemostratigraphy as a tool for chronostratigraphic correlation in strata with poor biostratigraphic control. The conodonts recovered from the LaPorte City Formation shows the utility of the small limestone formations on the northwest flank of the East-Central Iowa Basin for refining global Silurian conodont biostratigraphic zonation.

Conodonts are important biostratigraphic tools for the delineation and calibration of the geochronological boundaries within the Carboniferous and used generally as stage-boundary markers for the Lower Carboniferous (Mississippian). The studied successions in the Central and Eastern Taurides were mainly deposited in a shallow marine environment during the Carboniferous time and they comprise less abundant and diversified conodont fauna. The conodont fauna represented by twenty-four species belonging to ten genera have been described from the studied sections (AS / AAO / BSE and HB) in the Taurides (Turkey). Regarding the first occurrences and last occurrences of biostratigraphically significant species within these sections, the following zones have been established across the Lower Carboniferous successions: (1) Polygnathus inornatus Zone (Hastarian-Lower Tournaisian) / (2) Gnathodus cuneiformis &ndash / Polygnathus communis communis Zone (Ivorian-Upper Tournaisian) / (3) Polygnathus mehli mehli Zone (Ivorian-Upper Tournaisian) / (4) Gnathodus girtyi girtyi Zone (Brigantian-Upper Visean) / (5) Gnathodus girtyi simplex Zone (Pendelian-Lower Serpukhovian) / (6) Rhachistognathus muricatus Zone (Zapaltyubinsky-Upper Serpukhovian) and (7) Declinognathodus inaequalis - Declinognathodus noduliferus Zone (Bogdanovsky-Lower Bashkirian). Based on the recovered conodont assemblages, Visean - Serpukhovian boundary has been recognized by the first occurrence of Gnathodus girtyi simplex and the Mid-Carboniferous boundary is delineated by the first occurrence of Declinognathodus inaequalis, which is an index taxon for the basal part of the Bashkirian. Based on the microfacies studies it can be concluded that conodont elements essentially obtained from the crinoidal bioclastic packstone-grainstone, crinoidal packstone-grainstone, coated bioclastic grainstone, intraclastic grainstone and spiculite packstone facies in the studied sections. It can be concluded that that the occurrence of abundant crinoids are indicative criteria for the presence of conodonts. Additionally, geometric morphometric analyses of biostratigraphically important genus, Gnathodus, on the basis of data available in the literature emphasize the importance of numerical taxonomy and reveal that taxonomic revision of this genus is needed.

No description available.

Thesis (Ph.D.) -- Memorial University of Newfoundland, 1987. / Typescript. Bibliography: leaves 486-526. Also available online.

No description available.

This work is focused on conodont biostratigraphy of the Silurian/Devonian boundary interval in the Prague Synform. The Na Požárech and Praha-Radotín sections were selected in order to study conodont diversity and changes in conodont faunas in different carbonate facies - shallower and deeper-water limestones around the Silurian/Devonian boundary and also to test the assumption, whether differences in bathymetry affect the diversity of taxa of the family Spathognathodontidae. In total 22 samples were analysed, particularly 13 samples from the section Praha-Radotín and 9 samples from the section Na Požárech. All samples were processed in laboratory and the obtained conodont material was studied in detail. The conodont material is abundant in both sections (more than thousand elements) and shows a high diversity and disparity in the family Spathognathodontidae. In total 17 taxa were identified and a new species Zieglerodina petrea is described. This new taxon is easily recognizable because of a distinct morphology and could be usefull for the identification of the base of Devonian in the Prague Synform. Its potential use in global correlation will, however, need further and thorough studies. Also conodonts of the family Icriodontidae are surprisingly abundant in both sections. Thin sections (13 from...

The Paradox Basin is a northwest-southeast trending intracratonic basin that formed in southwestern Colorado, southeastern Utah and adjacent parts of Arizona and New Mexico during the late Paleozoic Era. During rise of the adjacent Uncompahgre Uplift (Ancestral Rocky Mountains), the rapidly subsiding basin was filled with over 2000 m of Permo-Pennsylvanian sediments that reflect a complex interplay of changing tectonic, paleoecological, and climatic conditions that resulted in cyclic packages of mixed lowstand and non-marine siliciclastics and highstand shallow-platform carbonates. The 150 m-thick Honaker Trail formation straddles the transition from mostly marine carbonates to mostly non-marine siliciclastics on the southwest shelf of the Paradox Basin during late Moscovian to early Gzhelian (late Desmoinesian to early Virgilian) time. The carbonate-dominated lower 70 m of the formation were divided into two 4th-order sequences and thirteen 5th-order cycles by Goldhammer et al. (1991). We subdivide the remaining overlying 80 m of the Honaker Trail Formation, up to the top of the Shafer Limestone into an additional five 4th-order sequences named, from lowest to highest, the Raplee Limestone (named herein as a replacement for "unnamed limestone" of previous literature), Little Loop Limestone, W"“130 Limestone, Mendenhall Sandstone, and Shafer Limestone sequences and provide a detailed sequence stratigraphic framework of the Raplee, Little Loop, and W-130 sequences. In addition, we provide a conodont sequence biostratigraphic framework for the southwestern (carbonate) shelf of the Paradox Basin to correlate these sequences to Midcontinent (eastern Kansas) cycles using Idiognathodus and Streptognathodus-dominated conodont faunas. From the conodont fauna described herein, the Raplee Limestone sequence likely correlates with the Dennis major cycle of the Midcontinent, and suggests a correlation between the Little Loop Sequence and the minor Hogshooter cyclothem. We also propose the extension of these species' biostratigraphic zones within the Paradox Basin: I. swadei, I. papulatus, I. eccentricus, and I. sulciferus; all of which have been defined by Barrick and Rosscoe (2013) and others as extinct in the Midcontinent Basin at the end of the Swope cyclothem.

Condodont biostratigraphy has been established for complete sections of the Mifflintown, Wills Creek, and Tonoloway formations along the Wills Mountain anticline in the Central Appalachians. Beds in the Central Appalachians formerly called the Rochester Formation have been renamed the Cosner Gap Member of the Mifflintown Formation. The type section of the unit is at Cosner Gap, northwest of Maysville, Granty Count, West Virginia. Use of the name, Rochester Fornation is restricted to the New York section. The succession of conodont faunas described for these formations range from latest Wenlock through Pridoli in age. The fauna includes 46 form species assignable to the form genera Hindeodella, Ligonodina, Lonchodina, Neoprioniodus, Ozarkodina, Panderodus, Plectospathodus, Spathoenathodus, and Trichonodella. Sixteen new form species are described and twelve of these are named: Ligonodina brevis, Ozarkodina edithae mariae, Q. typica intermedia, O. serrata, Q. sinuosa, O. ziegleri crassatoides, Spathognathodus bicornutus, S. primus highlandensis, S. primus multidentatus, S. tillmani, S. walliseri, and Synprioniodina lowryi. One platform species, possibly representing a new form genus, occurs in the upper Tonoloway Formation. The important European forms Spathognathodus sagitta bohemicus., S. snajdri, S. crispus, and S. steinhornensis eosteinhornensis, are reported for the first time from the Central Appalachians. Eleven multi-element conodont species are recognized using open nomenclature. The faunas of the S. sagitta bohemicus, S. snajdri, S. crispus, and S. steinhornensis eosteinhornensis zones correlate with the sagitta, snajdri horizon of the siluricus, crispus, and eosteinhornensis zones of Walliser. The S. bicornutus and S. tillmani zones are tentatively correlated with Walliser's crassa and latialatus zones. The ploeckensis Zone of Walliser was not identified, but its stratigraphic position would be similar to that of the unzoned interval of the middle third of the McKenzie Member of the Mifflintown Formation. / Ph. D.

The McMullin syncline is located in Smyth County within the Valley and Ridge Province of southwestern Virginia. The syncline lies in a recess along the northern periphery of the Seven Springs-Pulaski thrust and consists of seven small fault blocks which are complicated by three generations of folding, the the F2 and F3 folds trending oblique to nearly perpendicular to regional Appalachian trends. Two components of stress operated on the local area, a major one directed from the southeast and a lesser one from the southwest. The latter component resulted from rotation of the Seven Springs-Pulaski thrust. The Marion, Virginia area where the McMullin syncline occurs developed up-plunge from the Tennessee basin depocenter. The McMullin syncline includes the Middle Ordovician cartonate onlap package which was deposited over the lower Ordovician upper Knox Group during a major transgression. Altogether, 3519 conodonts representing 48 monoelement or multielement apparatuses and 19 form species were recovered. Biostratigraphically important conodonts recovered from this ramp to basin sequence include: Polyplacognathus friendsvillensis, Polyplacognathus sweeti, Eoplacognatus lindstroemi, Pygodus serrus, and Pygodus anserinus. The Polyplacognathus friendsvillensis-P. Sweeti evolutionary lineage is a valuable datum on which to base correlations in the Southern Appalachians. The datum in this study confirms that the transgression moved northwestward. The Lenoir and Arline Formations correlate with the Pygodus serrus Zone of Eergström’s (1971a) North Atlantic zonation and the Effna Formation with the lowermost Pygodus anserinus Zone. / Master of Science

Ph. D.