PALEONTOLOGICAL RESOURCE SIGNIFICANCE AND VULNERABILITY IN THE GRAND CANYON AND ENVIRONMENTAL IMPACT OF THE TRANSCANYON PIPELINE REPLACEMENT

Grand Canyon National Park (GCNP) contains one billion years of preserved ancient life, including the largest exposure of Paleozoic rocks in the world. Fossils in GCNP such as; trilobites, nautiloids, ferns, and reptile trackways provide an important source for research on ancient life. Monitoring protocols play a critical role in implementing the Paleontological Resources Preservation Act of 2009 and preserving significant and substantial paleontological resources. Anthropogenic impacts are of particular concern in GCNP when monitoring paleontology sites. Current monitoring efforts are focused on current and proposed Transcanyon Pipeline (TCP) construction and replacement. The TCP conveys the potable water for the North and South Rim villages and inner canyon facilities. The replacement of the TCP is currently undergoing an environmental analysis that includes evaluating the impact on paleontological resources. We are currently assessing the vulnerability and value of individual fossil sites using statistical models to determine erosional variables that are most related to the condition of a site. Original field data was collected between 2011 and 2015. Additional data documenting erosional factors and details related to vulnerability and significance were collected in 2016. Field and geospatial data were then used to create regression models assessing the relation between an erosion significance scale and erosional variables. Three models predicted which variables are best related to the erosion significance scale. The strongest predictors within the best fit model included: In situ vs float, preservation type, lithology, geologic formation, slope, and distance to springs. The other two models differed by incorporating two additional variables: presence of slope movement and distance to faults. Paleontology localities that contain these variables near the TCP are vulnerable to construction. The same method was used to predict the relationship between the condition score of a site and similar erosional variables. Preliminary results of this model show that the NPS paleontology monitoring form may be insufficient in accurately determining the vulnerability of a site. This is important for evaluating future monitoring and preservation methods for paleontology sites in all national parks.