Stratigraphy of the Ogallala Formation (Neogene) of Northern Kansas

Fluvial late Tertiary (Neogene) deposits underlie the surface of the dissected plateau that is the High Plains, and extend from Texas to South Dakota in a belt several hundred miles wide. The stratigraphy and paleontology of the Neogene Ogallala formation have been studied in northern Kansas and correlations made with type sections of the Ogallala formation, and Valentine, Ash Hollow, and Kimball members in Nebraska. Ogallala sediments were deposited by streams flowing eastward from the Rocky Mountain region in broad, relatively shallow, erosional valleys cut in Cretaceous bedrock. Initial alluviation of these valleys is represented by the Valentine member. As alluviation proceeded, sediments progressively overlapped gentle valley slopes, and minor divides were buried by sediments of the Ash Hollow member. The Kimball member transgressed most major divides, producing a coalescent alluvial plain. This surface is marked by an accumulation of calcium carbonate. The Ogallala contains fossil vertebrates, mollusks, and seeds. Fossil vertebrates, although having time significance, are of little local stratigraphic value. Molluscan faunas show an orderly progressive change bridging the interval from late Miocene (?) to earliest Pleistocene, and present distinctive assemblages in Valentine, Ash Hollow, and Kimball members. Abundant and widely dispersed fossil seeds are the most usable organic remains for regional stratigraphic work. Ten petrographically distinct volcanic ash falls occur in the Ogallala; seven have proved valuable in precise correlations throughout the region and with type localities in Nebraska. Lithologically, the Ogallala formation is heterogeneous, but each member presents certain gross characters distinguishing it from the others. The Valentine member is predominantly gray to greenish-gray feldspathic sand, only loosely cemented with calcium carbonate; it includes some clay and silt and local opal-cemented sandstone lenses. The Ash Hollow member is typified by gray to brown, feldspathic sand, silt, and gravel having irregular calcareous cementation; soft limestone; and numerous lentils of volcanic ash. The Kimball member, although containing local lentils of coarse gravel in the base, is predominantly calcareous feldspathic sandy silt capped by a massive to nodula

Petrology of the Pliocene Pisolitic Limestone of the Great Plains

Petrographic study of 34 oriented samples of pisolitic ("algal") limestone from the upper part of the late Tertiary Ogallala Formation in Kansas, Oklahoma, and west Texas indicates that the rock sampled was developed by predominantly soil-forming processes acting upon sands and silts of the uppermost Ogallala. The absence of fossils, replacement of sand grains by calcite, anomalous distribution of detrital grains with respect to oölites and bulbous structures, and the inverted orientation of the bulbous structures themselves, all argue against algal origin of the rock. The origin of the limestone is similar to that of the well-developed caliche in southeastern New Mexico described by Bretz and Horberg, except that limestone gravels were not required for formation of the Kansas rock. The concretionary structures are analogous to those formed in bauxites. Conditions favoring development of pisolitic limestone were (1) presence of rocks containing easily soluble minerals yielding residues rich in Ca2+ ion; (2) effective rock permeability; (3) deficient rainfall and long dry periods; (4) low topographic relief; and (5) time

Chemical, Petrographic, and Ceramic Properties of Four Clays from the Dakota Formation in Kansas

Four commercial-type clays from the Dakota formation were studied by chemical and spectrochemical analysis, x-ray diffraction, electron and light microscopy, differential thermal analysis, mechanical analysis, and specific surface measurements. The basic chemical and physical properties so determined are compared with pH, apparent viscosity, and the results of empirical ceramic tests, including water of plasticity, shrinkage water, pore water, volume and linear shrinkage, fired color, pyrometric cone equivalent, saturation coefficient, apparent porosity, apparent and bulk specific gravity, and hardness at various fired temperatures. Relationships between green properties and percentage water of plasticity and between green properties and specific surface are shown. The fired properties are shown to be more directly related to chemical and mineralogical composition. There is a correlation between percentage volume shrinkage on firing and percentage of fluxes contained in the clays. The basic properties explain the behavior of the clay materials when subjected to ceramic tests; and, conversely, easily obtained ceramic data can be used for rough determination of basic properties

Examining the Influence of COVID-19 on Elementary Mathematics Standardized Test Scores in a Rural Ohio School District

In the United States, national and state standardized assessments have become a metric for measuring student learning and high-quality learning environments. As the COVID-19 pandemic offered a multitude of learning modalities (e.g., hybrid, socially distanced face-to-face instruction, virtual environment), it becomes critical to examine how this learning disruption influenced elementary mathematic performance. This study tested for differences in mathematics performance on fourth grade standardized tests before and during COVID-19 in a case study of a rural Ohio school district using the Measure of Academic Progress (MAP) mathematics test. A two-way ANOVA showed that fourth- grade MAP mathematics scores were statistically similar for the 2019 pre-COVID cohort (n = 31) and 2020 COVID-19 cohort (n = 82), and by gender group, between Fall 2019 and Fall 2020. Implications for rural students’ academic performance in virtual learning environments are discussed

Novel concepts in virally induced asthma

Viruses are the predominant infectious cause of asthma exacerbations in the developed world. In addition, recent evidence strongly suggests that viral infections may also have a causal role in the development of childhood asthma. In this article, we will briefly describe the general perception of how the link between infections and asthma has changed over the last century, and then focus on very recent developments that have provided new insights into the contribution of viruses to asthma pathogenesis. Highlighted areas include the contribution of severe early life viral infections to asthma inception, genetic determinants of severe viral infections in infancy, the differences in innate and adaptive immune system cytokine responses to viral infection between asthmatic and nonasthmatic subjects, and a potential vaccine strategy to prevent severe early life virally-induced illness

Annual review of the iron mining and other industries of the Upper Peninsula /

Description based on: year ending Dec. 31, 1880.Mode of access: Internet

History and review of copper, iron, silver, slate and other material interests of the south shore of Lake Superior.

Mode of access: Internet

Reply of the Alaska Commercial Company to the charges of Governor Alfred P. Swineford, of Alaska, against the company in his Annual report for the year 1887.

Mode of access: Internet