Browsing by Subject "Stratigraphic -- Pennsylvanian"
Now showing 1 - 14 of 14
Results Per Page
Sort Options
Item A carbon isotope and trace element analysis of Pennsylvanian rugose corals, North-Central Texas(Texas Tech University, 1989-12) Perkins, DianeCarbon and oxygen isotopes were analyzed to identify the process of algal symbiosis in Pennslyvanian rugose corals from the Graham Formation of north-central Texas. Because original oxygen and carbon isotopic compositions depend on the preservation of isotopic content during post-depositional diagenesis, trace element and petrographic analyses were used to determine the suitability of samples of Caninia, Lophophyllidum and the brachiopod Composita for analysis. Petrographic analysis of fossils from the Finis Shale indicate that these fossils have been subjected to four episodes of diagenetic cementation. Shell microstructures are partially preserved in Composita and Caninia. Recrystallization of the shell was more extensive in Lophophyllidum from the Finis Shale and Caninia from the Gunsight Limestone. Six episodes of cementation are recognized in Caninia from the Gunsight Limestone. Trace element analysis indicates that sodium and magnesium values are depleted and iron and manganese concentrations enriched in Caninia from the Finis Shale. Trace element analysis of Composita indicate that sodium, iron, manganese and strontium concentrations are within the observed range for Paleozoic brachiopods. Isotopic analyses of Caninia and Lophophyllidum exhibit 6 ^^C and 6 ^^0 values depleted compared to Composita and to the postulated range for carbonate precipitated in equilibrium with Pennsylvanian seawater. These findings suggest that an algal symbiont influenced the development of the coral skeleton.Item A study of Pennsylvanian-Permian arkoses in north-central New Mexico(Texas Tech University, 1950-05) Butler, RoyNot availableItem A subsurface study of the Pennsylvanian detrital unit, Andrews County, Texas(Texas Tech University, 1985-08) Krenik, Kevin JNot availableItem Deposition and diagenesis of the Shafter Lake San Andres Formation, Andrews County, Texas(Texas Tech University, 1985-08) Glenn, Sidney ENot availableItem Deposition, diagenesis and porosity relationships of the Odom Limestone(Texas Tech University, 1978-08) Webb, ChriscynthiaNot availableItem Depositional environments and diagenesis of Cisco carbonates(Texas Tech University, 1980-12) Baldwin, Randall WayneNot availableItem Depositional environments of Morrowan sandstones, Carlsbad Field, Eddy County, New Mexico(Texas Tech University, 1980-12) Hurley, Timothy JamesNot availableItem Geologic Structure of the Pennsylvanian Rocks, Tecolote Mountain Area, New Mexico(Texas Tech University, 1951-08) Stever, Rex HaleNot Available.Item Lower Pennsylvanian stratigraphy of the Central Colorado Trough(Texas Tech University, 2003-08) Musgrave, Bryan EdwardThe Central Colorado Trough formed as a result of the uplift of the Ancestral Rocky Mountains. With uplift, sediments were eroded from the adjacent highlands and deposited in the trough. The Lower Pennsylvanian stratigraphy of the Central Colorado Trough was determined based on outcrops in the southern Mosquito Range and Arkansas River Valley east of Salida, Colorado. The Kerber Formation is the oldest Pennsylvanian strata in the Central Colorado Trough and was derived from the erosion of older Paleozoic sedimentary rocks and some crystalline basement rocks. It was deposited in alluvial fan and braided streams environments near the edges of the trough. Along the axial portion of the Trough, it was deposited in braid-delta and shallow marine environments. As marine incursion occurred from the northwest, a retrogradational sequence developed. Based on conodont faunas, the upper Kerber Formation is late Morrowan to Atokan in age. Because the strata of the Central Colorado Trough are intimately related to the initial uplift of the Ancestral Rocky Mountains, the formation of the Ancestral Rocky Mountains began no later than the late Morrowan. The Kerber Formation correlates with the Belden Formation of the northern portion of the Trough based on the first appearance of the conodonts Idiognathoides sinuatus, Idiognathodus sinuosus, and Idiognathodus parvus. At Willard Springs they occur within the Belden, whereas they occur within the Kerber at Wells Gulch, 8 km to the south. The dark marine sediments of the Belden Formation extend further southward than previously documented, and approximately 127 m of section occurs at Willard Springs, northeast of Salida. At Willard Springs, the Belden Formation lies conformably above the Kerber Formation and conformably below the Sharpsdale Formation. This is the first time that the Belden has been documented m contact with the Sharpsdale Formation. At Wells Gulch and Box Canyon to the south, the Belden Formation grades into shallow-water carbonates and shales interbedded with Kerberand Sharpsdale-type elastics. The Sharpsdale Formation was derived from the erosion of Precambrian crystalline basement rocks of the Uncompahgre Highland as the climate of the Pennsylvanian grew more arid. It was deposited in alluvial fan and braided stream environments near the edges of the trough. Along the axial portion of the trough, it was deposited in braid-delta and rare shallow marine environments. A northward prograding sequence developed as sediment influx exceeded local sea-level rise.Item Paleontology and geology of an upper Pennsylvanian tetrapod locality from the Ada Formation: Seminole County, Oklahoma(Texas Tech University, 1999-12) Kissel, Richard AnthonyThe paleontology, taphonomy, stratigraphy, depositional setting, and paleozoogeographic significance of an Upper Pennsylvanian tetrapod-bearing fossil locality is presented. The site, OMNH Locality V1005, is located within the Virgilian Ada Formation in southcentral Oklahoma, north of the town of Ada. The fossiliferous outcrop represents a meandering stream deposit, with the majority of the exposure consisting of fine-grained overbank (floodplain) deposits. The fossil material is found within a single horizon that stretches 11 meters along the face of the outcrop. This horizon is located within a gray mudstone unit and is 22.4 meters above the contact between the Ada Formation and the imderlying Vamoosa Formation. The bone-bearing interval is further characterized by the presence of granule-sized carbonate rock clasts and carbonized plant material. Tetrapod fossils recovered fi-om the Ada locality include the remains of at least six taxa, with remains of the pelycosaurian-grade synapsid Ophiacodon cf O. mirus constituting the majority (90 percent) of the fossil material collected and identified. Other taxa include the diadectid Diasparactus zenos, the temnospondyl ?Eryops sp., and three unidentified taxa known only from jaw fragments. An absolute minimum of five Ophiacodon individuals were recovered from the site, including the remains of both mature and immature individuals. Moreover, the material recovered from the Ada locality suggests, for the first time, the presence of size-based sexual dimorphism within the genus Ophiacodon. Linear measurements of the larger dimorph are approximately 1.5 times as great as those of the small form. No gender assignment is suggested. Of the five remaining taxa, no evidence supports the presence of more than one individual of each taxon. Except for four articulated vertebral segments, all of the fossil material collected in situ was disarticulated. The presence of articulated vertebral sequences, while all other skeletal elements are isolated and disarticulated, suggests that the vertebral column represents the last stage of the disarticulation sequence of an Ophiacodon corpse. The vertebral segments are straight and relaxed, which indicates that the corpses decomposed in water. All of the in situ bones are complete except for the anterior margin of a scapulocoracoid and the puboischiadic plate of a pelvic girdle. The bone surfaces exhibit no indication of cracking or flaking and, thus, were not exposed to prolonged periods of weathering at the surface. All fractures are indicative of post-burial breakage. The hypothesis that the bones were buried relatively quickly after the individuals' deaths is also supported by the lack of tooth marks and other evidence of scavenging. The fossil material represents a transported assemblage and the orientation of the long bones indicates that flow direction was either northwest or southeast during the time of deposition. Furthermore, the dip of several bones relative to the stratification suggests rapid deposition under flood conditions. OMNH Locality VI005 significantly extends the paleozoogeographic range of the taxa recovered. Diasparactus zenos is no longer restricted to the Upper Pennsylvanian deposits of El Cobre Canyon, New Mexico, and, thus, can no longer be considered endemic to that region. The Ada locality records the first Late Pennsylvanian report of Eryops outside of Pennsylvania. It also presents the first occurrence oi Ophiacodon within the Upper Pennsylvanian units of Oklahoma. Furthermore, O. mirus has been positively identified fi-om only the Lower Permian of New Mexico. If the Ada Ophiacodon is indeed referrable to O. mirus, then OMNH Locality VI005 extends both the stratigraphic and geographic range of this species to include the Upper Pennsylvanian of central Oklahoma.Item Pennsylvanian stratigraphy of Tecolote Area, New Mexico(Texas Tech University, 1951-05) Pittman, Gardner MNot availableItem Petrographical, petrophysical, and biostratigraphical investigation of the Caddo Limestone (Pennsylvanian) Stephens County, Texas(Texas Tech University, 2001-12) Miller, Matthew CThe Pennsylvanian Caddo Limestone (Desmoinesian) of Stephens County, Texas, is a thick-hydrocarbon bearing carbonate unit. The uppermost Caddo is an algal-mound structure formed by the sediment-baffling effect of phylloid algae. Two cores south and southeast of Breckenridge, Texas were investigated petrographically and using geophysical logs. Within the cored intervals, multiple shallowing-upward mounding cycles can be recognized. Six depositional lithofacies were recognized and were associated with six depositional environments. These associations are: (1) Sponge Spiculite - Deep Water, (2) Fusulinid - Crinoid - Komia Packstone/Grainstone - Debris Bed or Capping Unit, (3) Phylloid Algal Wackestone - Mound Core, (4) Skeletal Wackestone - Near Flank Beds, (5) Carbonate Clast - Wackestone - Intermound, and (6) Skeletal Ooid Grainstone and Fusulinid - Crinoid – Komia Packstone/Grainstone - Capping Unit. The Caddo algal mounds follow a typical mounding pattern: (1) Deep Water, (2) Debris (stabilization of the deep water substrate), (3) Mound Core - Near Flank- Intermound (upward mound growth and lateral mound migration, and (4) a Capping Environments (termination of mound growth). The algal mounds original depositional fabric is heavily modified by four stages of diagenesis: (1) syndiagensis, (2) marine, (3) multiple phases of meteoric, and (4) deep (burial). Meteoric diagenesis had the largest modifying effect in the original depositional fabric. Three major relative sea level fluctuations occurred within the Caddo algal mounds, producing three mounding cycles. Correlation of cored wells and geophysical logs in the studied area lead to the determination of a progressive step wise westward termination of the Caddo algal mounds were a result the migration of the fore bulge (Bend Arch) associated with tectonic loading of the Ouachita Thrust Belt. Progradation of prodeltaic and basinal terrigenous sediments derived from the Ouachita thrust belt across the Caddo algal mounds in one event. The termination of the Caddo algal mounds, by drowning is time transgressive getting progressively younger in the westward direction.Item Subsurface geology of the Dalhart Basin, Texas Panhandle(Texas Tech University, 1980-08) McCasland, Ross DuncanThe Dalhart Basin is a small intra-continental basin located in the northwestorn corner of the Texas Panhandle. It occupies most of Dallam and Hartley Counties and extends south into Oldham County and north into Cimarron County, Oklahoma. The stratigraphic sequence consists of a variety of lithic types. Pennsylvanian and lower Permian (Wolfcarnp) sediments, which comprise most of the sediments of the basin, include: carbonates, granite wash (arkosic conqlomerate), fine sand and shale.. The granite wash and other clastics appear to have been derived locally from the Bravo Dome and the Amarillo Uplift which are situated southwest and southeast of the Dalhart Basin, respectively, and from the Sierra Grande Arch and the Pedernal Uplift, both of which are situated to the west. Downwarping and major faulting characterized the Pennsylvanian. By early Permian time nearly all structural deformation had ceased, and before the end of the Wolfcampian sediments virtually had infilled the basin. Faulting and downwarping was most intense in northeastern Oldham County and in Hartley County. There is promise that the Dalhart Basin will become a productive petroleum province. Recent granite wash discoveries combined with present economic incentives will undoubtedly generate future exploration.Item The sedimentary petrology of the Pennsylvanian system of the Upper Pecos Valley, New Mexico(Texas Tech University, 1948-08) Haliburton, John LeoNot available