DINOS TO DENALI: THE RECORD OF MESOZOIC THROUGH CENOZOIC TECTONICS, SEDIMENTATION, VOLCANISM, AND GEOMORPHOLOGY IN DENALI NATIONAL PARK AND PRESERVE, ALASKA

Denali National Park and Preserve is known for the majestic and high-standing peaks of the central Alaska Range, notably the massif of Mt. McKinley (6194 m; also known as Denali). Yet the park contains an extensive geologic record extending back to the Precambrian. In particular, Mesozoic and Cenozoic geologic features are particularly well-suited for remote, digital investigations. In the Mesozoic, an oceanic plateau (Wrangellia) accreted to the North American continental margin creating a large suture zone and sedimentary basin. In the Cenozoic, ongoing deformation along the intracontinental Denali fault lead to uplift and formation of the highest point in North America (Mt. McKinley). Overall, this region records the complex tectonic record of terrane accretion, syntectonic sedimentation, volcanism, pluton emplacement, restraining bend formation, and slip-partitioning across a major strike-slip fault system. The long-lived southern Alaska convergent margin is reflected in the diverse magmatic history of this region with the remarkably colorful Paleocene Teklanika Volcanics providing a foreground to many photos of Mt. McKinley. Interwoven with this tectonic record are insights into Late Cretaceous high-latitude dinosaur activity, glacial geomorphology and periglacial surface processes, and the interplay between tectonics, climate, and sedimentation. Geomorphic evidence for active deformation in the form of fault scarps, displaced landforms, and extreme relief combined with geologic/thermochronologic records provide a geologic explanation for the extremely anomalous topography of Mount McKinley both in asymmetry relative to the adjacent right-lateral Denali fault and the isolated nature of the high-topography relative to the rest of the Alaska Range. The remote nature of this region relative to limited roads and points of entry, the sub-arctic setting, the sheer size of the mountains, and the geologic/geomorphic diversity make Denali National Park and Preserve an ideal destination for guided digital geologic investigations. For a complete experience, students should provide their own mosquitoes, grizzly bears, and cold rain.