Final Report to Sequoia and Kings Canyon National Park, National Park Service / Cooperative Agreement No. CA 8000-1-0002

The eastern side of the Guadalupe Mountains, located in New Mexico and west Texas, represents an erosional profile along the Capitan reef margin. A complete shelf-to-basin exposure of the Upper Permian Capitan shelf margin is found on the north wall of North McKittrick Canyon, which is nearly perpendicular to the Capitan reef margin. An excellent 2-D sequence stratigraphic framework for upper Permian backreef facies has been developed by previous workers for North McKittrick Canyon (Tinker, 1998) and Slaughter Canyon (Osleger, 1998), forming the basis for observations in this study. The goal of this study is to describe the sequence stratigraphic architecture of the Yates Formation, focusing on the Y4-Y6 high-frequency sequences (HFSs) found in the middle to outer shelf depositional systems, and to illustrate the use of airborne lidar data to quantitatively map at the cycle-scale. Seven measured sections were taken in North McKittrick Canyon. From airborne lidar, 3-D geometries of key sedimentary and structural features were mapped in Polyworks, in addition to the sequence boundaries delineating the Yates 4-6 HFSs. In general, major cycles exhibit asymmetry and shoal upward. Cycle boundaries are sometimes hard to delineate due to amalgamation, particularly in the shelf crest. High-frequency sequences are commonly asymmetric; they deepen and thicken upward toward the maximum flooding surface, and the boundaries between HFSs are usually marked by thick siltstones. Major HFS boundaries can be mapped across the entire dataset, and some component cycles can be observed for minimum distances of one kilometer in an updip-downdip direction. Also, some facies tract dimensions can be estimated directly from the lidar data. Measured sections indicate that the shelf crest facies tract shifts seaward with each successive HFS, while the outer shelf facies tract steps landward. Future work that could be done with the Y4-Y6 HFSs includes 8-10 more measured sections, collection of samples for thin sections, and tracing out of contacts between facies tracts. Extensive lidar data interpretation needs to be done so that digital outcrop models demonstrating facies distributions can be produced. This would enable the development of an outcrop analog model to mixed carbonate-siliciclastic reservoirs, which would be unprecedented in this area. / text

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The historically introduced House Rock Valley bison herd has, in recent years, migrated from the eastern Arizona Strip onto the Kaibab Plateau within Grand Canyon National Park. Bison are considered a nonnative species to the southern Colorado Plateau, and the animals adversely impact sensitive ecosystems prompting National Park Service wildlife managers to pursue their removal. Archaeofaunal evidence of bison in the Grand Canyon and neighboring regions, however, raises concern that bison may in fact be native. Assessing the evidence within a zooarchaeological interpretive framework is critical since mere presence/absence lists of bison remains do not address the potentially complex cultural processes involved in the formation of archaeofaunal assemblages. Inter-assemblage comparisons illustrate a decline in relative abundance and skeletal completeness correlated to distance from traditionally understood historical bison distribution. If bison were present in the Southwest, as the evidence suggests, they likely entered the region only occasionally as small, dispersed herds.

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In Recreating Nature: Ecocritical Readings of Yosemite and Grand Canyon, I examine the intersections of culture and nature in two prominent national parks, and I consider the implications of nature-tourism in the environmental discourse of the U.S. Covering a period from 1848 to the present, my project aims to correct an oversight in scholarship about the park system, in which legacies of colonialism and imperialism--when addressed at all--tend to be historicized and framed as the age-old sins of a presumably reformed national politic. Instead, I examine both historical and present-day developments, emphasizing the profound cultural influence of the places we designate as natural. I define ecocriticism as an inherently interdisciplinary endeavor attuned to the interconnectedness of things. My methodology is to engage texts, images and other expressions of the national parks in a process of extended close reading and comparative analysis. While observing the particular contexts of each case, I attempt to locate these texts amidst the broadest but most essential critical terrain: they each negotiate a dialogical relationship between culture and nature. By setting the stage for examining the human and its relation to the non-human other, the parks have become key sites for displaying the recreation of nature. After my introduction I discuss John Muir's My First Summer in the Sierra, focusing on an episode where Muir risks his life for a view from Yosemite Falls. I also consider Muir's failure to empathize with Native Americans he encountered. In my next chapter I analyze John Wesley Powell's Exploration by focusing on his attempt to assert authority over a region by prioritizing the scientific tone in his writing. Next I synthesize historical and contemporary sources, discussing Mary Colter's Grand Canyon architecture alongside the Grand Canyon Skywalk, a glass-bottom walkway on the Hualapai Indian reservation. In the following chapter I compare the acrophobia-inducing photographs of George Fiske and Emery Kolb. Finally, I discuss transit real and imagined in Grand Canyon and Yosemite, considering the utopian potential of national parks. I close by revisiting questions about our changing environmental discourse and about the future of ecocriticism.

Gas hydrate has been identified by drilling in Alaminos Canyon block 818, within the Perdido Fold Belt, outboard of the Sigsbee Escarpment, in approximately 2750 meters (9000 feet) of water. At the location of the AC818 #1 (“Tigershark”) well, the gas hydrate occurs within the top 20 m (65 feet) of an approximately 90 meter (300 feet) thick Oligocene Frio sand, a volcaniclastic sandstone rich in lithic fragments, feldspar, and volcanic ash. The Frio reservoir is folded into a 4-way closed anticline. At the crest of the anticline, the sand is partly eroded and is unconformably overlain by 450 m (1500 feet) of Pleistocene shale and sand. The unconformity surface is also in a 4-way closed geometry and defines the top of the hydrate reservoir at the well. The rock is poorly consolidated and has porosity as high as 42% from log data. LWD logs indicate that the hydrate zone has high resistivity and high P-velocity (2750 mps: 9000 fps). The underlying wet sand at the base of the gas hydrate stability zone (GHSZ) has low resistivity and P-velocity (Vp: 1500 mps: 5000 fps). The very low Vp indicates the presence of low-saturation free gas ("fizz gas"). The large velocity contrast creates a strong response in seismic data which was inverted into a 3D gas hydrates saturation (Sgh) volume. Elsewhere in the GHSZ, seismic character was used to predict predominant sediment facies. Relative high stand facies, which are more clay-rich, will generally be characterized by more continuous and parallel seismic reflectors. In contrast, relative low stand facies, which have more sand content, will be characterized by more hummocky, discontinuous seismic character and will often lie on erosional surfaces, particularly in uncompacted sediments. Understanding the stratigraphy throughout the section is important, since sand will often provide beneficial reservoir conditions, while clay will provide more impervious sealing qualities. The seismic interpretation also identifies migration pathways, such as faults and gas chimneys, and the presence of available gas, which are necessary to charge reservoirs within the HSZ.