<p>This dataset contains results of a palynological study completed by Dr. Robert L. Raven from the IRF Group Inc in December 29, 2018</p> <p><br></p> <p>Palynological analysis was performed on siltstone samples that were collected from 4 outcrops of cenozoic strata from the study area of Chapter 3 in the eastern Alaska Range. This file includes the results of that study and detail about he present pollen assemblages as well as images</p> <p><br></p> <p>Jeffrey Benowitz contracted this work</p>

The post-orogenic history of the Appalachian Mountains, particularly the persistence of rough topography and the degree of river incision throughout the region, has been a longstanding focus of geomorphology studies. Numerous models have been developed to explain the evolution of this landscape, variously invoking episodic or continuous processes of uplift and erosion to drive the generation or reduction of topographic relief. Recently, late Cenozoic uplift has found favor as a mechanism for rejuvenating the topography of the southern and central Appalachians. This hypothesis has drawn on longitudinal river profiles, seismic tomography, and offshore sediment records as evidence of Neogene uplift.<div><br></div><div>Radiometric dating of surficial deposits provides a means to directly test models of episodic and continuous landscape evolution, as well as the Neogene uplift hypothesis. The research described in this thesis dates surficial sediments (river terraces, alluvial fans, and a filled sinkhole) and supergene manganese oxides using 26Al/10Be burial dating and 40Ar/39Ar geochronology, respectively. Our cosmogenic 26Al/10Be dating provides detailed histories of aggradation and incision along the Shenandoah and Tennessee Rivers since the early Pliocene. 40Ar/39Ar dating of manganese oxides permits estimates of surface preservation and denudation in the Shenandoah Valley and nearby watersheds throughout the Cenozoic.<br></div><div><br></div><div>The results of our work in the Shenandoah Valley, Tennessee River basin, and intervening areas indicate that the Appalachians experienced no significant pulse of uplift during the Cenozoic. Long-term preservation of supergene manganese oxides dates as far back as the Eocene, demonstrating minimal denudation and discontinuous formation that lend evidence to episodic landscape evolution models. Cosmogenic26Al/10Be burial ages along the Shenandoah and Tennessee Rivers reveal Pliocene aggradation, with enhanced deposition in the Shenandoah Valley during the mid-Piacenzian Warm Period. Both rivers likely experienced incision during the Pleistocene, likely due to climatic fluctuations. These results demonstrate that while the Appalachian landscape has remained largely unchanged for tens of millions of years, rapid Pleistocene changes in base level recently triggered significant incision of major drainages.<br></div>

<p>The Geologic <i>TimeScale Creator </i>(TSCreator) project has compiled a range of paleo-environmental and bio-diversity data which provides the opportunity to explore origination, speciation and extinction events. My PhD research has four major interconnected themes which include the visualization methods of evolutionary tree and the impacts of climate change on the evolution of life in longer and shorter timeframes: <b>(1) </b>Evolutionary range data of planktonic foraminifera and nannofossils over the Cenozoic era have been updated with our latest geological timescale. These evolutionary ranges can be visualized in the form of interactive, extensible evolutionary trees and can be compared with other geologic data columns. <b>(2) </b>A novel approach of integrating morphospecies and lineage trees is proposed to expand the scope of exploration of the evolutionary history of microfossils. It is now possible to visualize morphological changes and ancestor-descendant lineage relationships on TSCreator charts which helps mutual learning of these species based on genetic and bio-stratigraphic studies. <b>(3) </b>These evolutionary datasets have been used to analyze semi-periodic cycles in the past bio-diversity and characteristic rates of turnover. Well-known Milankovitch cycles have been found as the drivers of fluctuations in the speciation and extinction processes. <b>(4) </b>Within a shorter 2000-year time period, global cooling events might have been a factor of human civilization turnover. Using our regional and global cultural turnover time series data, the effect of climate change on human culture has been proposed. The enhancement of the evolutionary visualization system accomplished by this research will hopefully allow academic and non-academic users across the world to research and easily explore Earth history data through publicly available TSCreator program and websites. </p>