Tanner to the Little Colorado River Natural History Backpack April 3-9, 2020 with Melissa Giovanni CLASS INFORMATION AND SYLLABUS DAY 1 Meet at 10:00 a.m. at the historic Community This class focuses on the geology, anthropology, Building in Grand Canyon Village (Google Map). ecology, and history of eastern Grand Canyon. We will orient ourselves to the trip and learn some This route is unique among South Rim hikes due basic concepts of geology as well. We will first to the stunning exposures of most of the major spend some time on introductions and gear, food, rock groups that compose the walls of Grand and the class. After lunch we will have a short Canyon. While we will not be able to view the session in the classroom and then go out to the deepest and innermost crystalline and rim (and perhaps partway down one of the major metamorphic rocks, we will see exposures of the trails) to become familiar with regional geography younger Precambrian strata unequaled anywhere and landmarks. We will also cover fundamental else. geology tenets that lay the ground work for the rest of the class, including: The class also provides superb views of underlying structural features, including faults, A geographic overview of the region unconformities, and intrusions not visible The three rock families; how they form and elsewhere. We will see one of the most profound how this is reflected in their appearance faults in Grand Canyon, one that may have played The principles of stratigraphy a major role in the formation of the canyon itself. Introduction to the rock formations of the We will also pass through one of the most Grand Canyon. ecologically and archaeologically significant sections of the river corridor, skirt the remains of DAY 2 early mining operations, and hike to the Little Colorado River. This largest of Grand Canyon's We meet at the Community Building (Google tributaries begs discussion of the roles of the river Map) before carpooling the 25 miles to the Tanner and canyon in the lives and mythology of local Trailhead at Lipan Point. We will hike all the way American Indians. This hike therefore offers an to the river today, a distance of about 11 miles and excellent and quite diverse learning experience. 4,700 vertical feet. While hiking we will explore the Paleozoic sedimentary rocks we are passing The time allotted for this hike does not reflect the through and begin a discussion of the Paleozoic actual length of the hike. Instead, we have allowed history of the region. In addition, we begin our time to move slowly and explore the features we travels through the younger Precambrian Grand encounter, as well as time for participants to Canyon Supergroup--sedimentary strata explore on their own or just enjoy some solitude. intermediate in age between the Paleozoic strata and the Precambrian crystalline rocks of the canyon's Inner Gorge. Our camp is at Tanner Rapid, where we will stay for two nights. DAY 3 The area around Tanner Rapids has a wealth of geologic, geomorphic, and archeological features, so today is set aside as a layover day to explore our surroundings. We will most likely day hike downstream towards Unkar Rapids, passing one of the most ecologically significant areas of the (in Grand Canyon terms), although there are a eastern Grand Canyon. Cardenas Camp along the couple of short climbs away from the river. In river is one of the richest post-Glen Canyon Dam addition, we will be hiking around and exploring riparian sites in this region in terms of vegetation the area. Camp will be for two nights at the and is the protected nesting site of the endangered junction of the Dox Formation, Cardenas Lavas, willow flycatcher. Our topics of discussion and and Palisades Fault; where John Wesley Powell exploration may include the following: defined the beginning of his “Grand Canyon of the Colorado River”. The Grand Canyon Supergroup: its origins, rock types, and structures. DAY 5 Geologic time and the Cardenas Lavas: their origins and ancient geography. Today, we will hike without backpacks along the Modern river processes: debris flows, rapids, Beamer Trail to the Little Colorado River, about 5 and how rapids work. miles one-way. This hike stays atop the Tapeats Sandstone most of the way, and affords excellent Archeology of Grand Canyon: the Anasazi views of the river and important geologic features. and Cohonina in the Furnace Flats area. While on the bench, the hiking is predominantly Glen Canyon Dam and changes to the level, with a 400-foot climb to ascend then riparian ecosystem since 1963. descend the Tapeats. Our hiking today will be largely over rolling The Little Colorado River is important as well as terrain, with one 400-foot climb if you wish. We interesting in geologic, archaeologic, historic, and may travel as far as 10 miles round trip. Camp is environmental terms. Near its mouth we will again, at Tanner Rapid in the Upper Dox address the following subjects: Formation. Modern river processes and carbonate DAY 4 (limestone) processes. Today we spend part of the morning discussing The role of the Little Colorado in Hopi the several ideas for timing and mechanism of the mythology. formation of the canyon. The Butte Fault is clearly The role of the Little Colorado in modern visible from the Tanner campsite, and we will environmental battles. discuss its role in the process of canyon cutting. Grand Canyon Environmental Impact We will have the opportunity to discuss any other Statement. topics we didn't have a chance to cover on the The historic significance of the Beamer Cabin, previous day before moving our camp upstream Chuar Butte, and other local features. to Palisades Creek. This hike will take us by archeologically significant areas, allowing us to We will return to Palisades Creek for camp. view some of the stabilization and conservation efforts being made in the area. DAY 6 At camp we can explore the Palisades Fault and From Palisades Creek, we begin our hike out of the Palisades of the Desert, as well as some turn- the canyon. Because we will be making the 14- of-the-century mining efforts visible at the mile journey in two days, we will take some time McCormick Mine. This region also provides an along the way to summarize major points and opportunity to observe the following subjects: stories we have discussed. Our camp will be either at Tanner Rapid or along the Tanner Trail on the Volcanic rocks and features way up, depending on group preference. If we Faults, folds, and other geologic structures choose to leave the river and dry camp along the Mass wasting and other modern erosional Tanner Trail, we will need to fill up with water at processes Tanner Campsite before beginning the climb. Mining in the Grand Canyon: when, why, and DAY 7 how much? We continue the climb out along the Tanner Trail. The hike from Tanner to Palisades Creek is Once we top out at the rim we will gather for a approximately 3 miles. The terrain is mostly level final class summary and farewells (maybe even a RECOMMENDED READING late lunch!). Anderson, Michael F. Living at the Edge: Explorers, NOTE: The weather this time of year should be Exploiters and Settlers of the Grand Canyon Region. nice, but it can be hot (in the 90s during the day). Be prepared with a hat, sunscreen, and long- Coder, Christopher M. An Introduction to Grand sleeved shirt. You will need at least 3 quarts of Canyon Prehistory. water for yourself during the day, and we will need a few larger collapsible containers to carry water Pocket Naturalist Field Guide to the Grand Canyon. for the group if we dry camp. Price, Greer. An Introduction to Grand Canyon ABOUT THE INSTRUCTOR Geology. Melissa Giovanni has been trekking around and Ranney, Wayne. Carving Grand Canyon. exploring the Southwest for 20 years and considers the desert to be her true home. She first Sadler, Christa. Life in Stone. visited the Grand Canyon while an undergraduate geology student at the University of Arizona, Thayer, David. An Introduction to Grand Canyon where she ultimately earned her B.S.. Melissa then Fossils. moved to UCLA for her Ph.D., also in geology. While her doctoral studies focused on the Whitney, Stephen R. A Field Guide to the Grand geological evolution of the Peruvian Andes, she Canyon. discovered her passion for teaching and led her very first field trip to the Grand Canyon while still Tanner Trail Guide a grad student. These books and other interpretive aids can be During a decade of teaching geology at two purchased at Grand Canyon Conservancy different universities, Melissa was able to develop bookstores on the north and south rims, online at her field teaching skills in locales all around www.grandcanyon.org, or by calling 800-858- Arizona, Utah, and Nevada. Currently a professor 2808. GCC members receive a 15% discount. at the College of Southern Nevada, she teaches both environmental science and geology. She continues to take students and the public out on field trips across the West. Melissa is ecstatic to be involved with the Field Institute and sharing her passion for the earth sciences with park visitors. When at home in Las Vegas, she can be found climbing and hiking in Red Rock Canyon, training as a competitive Masters swimmer, and serving as a Board member for the Southern Nevada Conservancy. .