Changing Landscapes Fifth Grade Pre- and Post-Visit Activity Guide
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National Park Service U.S. Department of the Interior Zion National Park Utah Changing Landscapes Fifth Grade Pre- and Post-Visit Activity Guide NPS/MARC NEIDIG Changing Landscapes Fifth Grade Pre- and Post-Visit Activity Guide Zion National Park Springdale, Utah 84767 Contents Introduction 1 Core Connections 1 Background 1 Pre-Visit Activities 3 Earth’s Power Punches 3 Rock On Zion! 4 Then and Now 6 Post-Visit Activities 8 Map Minds 8 It Happened Here! 9 Future Forecasters 11 Glossary 12 References 14 Introduction Background Theme Zion National Park is located along the edge The Earth’s surface is a dynamic system that is of a region called the Colorado Plateau. Uplift, constantly changing due to weathering, tilting, and the erosion of rock layers formed erosion, earthquakes, volcanoes, and uplift. a feature called the Grand Staircase, a series of colorful cliffs stretching between Bryce Focus Canyon, Zion, and the Grand Canyon. The activities focus on relationship between NPS PHOTO geologic processes and changes on the Earth’s Zion has spectacular geology. The arid climate surface. and sparse vegetation expose bare rock and reveal the park’s geologic history. Evidence Pre-Visit Activities of deposition (sedimentation), lithification, 1. Earth’s Power Punches – Students view a uplift, weathering, erosion, tectonics, and presentation of digital images showing the volcanic activity make the park a showcase for forces that shape the Earth’s surface. Then changing landscapes. students view images from Zion and deter- mine which geologic forces have contributed Deposition (Sedimentation) to the landscapes shown. Finally, students Zion National Park was a relatively flat basin discuss which landscapes were formed slowly near sea level 275 million years ago, near the NPS PHOTO and which were formed quickly. coast of Pangaea, the land area believed to have once connected nearly all of the earth’s 2. Rock On Zion! – Students will learn how landmasses together. As sands, gravels, and Zion was formed and evaluate how muds eroded from surrounding mountains, weathering and erosion contributed to the streams carried these materials into the formation of the rock layers and subsequent basin and deposited them in layers. The sheer carving of the canyon. weight of these accumulated layers caused the basin to sink, so that the top surface 3. Then and Now – Students will explore what always remained near sea level. As the land the area surrounding Zion might have been rose and fell and as the climate changed, the NPS PHOTO like during past geologic times when each depositional environment fluctuated from Landslides, flashfloods and earthquakes continue to play layer was formed. By creating posters, the shallow seas to coastal plains to a massive a role in shaping Zion National students depict Zion during past geologic desert of windblown sand. This process of Park. times and compare with the park today. sedimentation continued until over 10,000 feet of material accumulated. Post-Visit Activities Core Connections 1. Map Minds - Using a topographic map Lithification of Zion, students identify geological features Mineral-laden waters slowly filtered Utah Core Curriculum (e.g., valleys, canyons, buttes, mesas) and through the compacted sediments. Fifth Grade Science describe changes resulting from erosion. Iron oxide, calcium carbonate, and silica Standard 2: Students will acted as cementing agents, and with pressure understand that volcanoes, 2. It Happened Here! - Students draw on the from overlying layers over long periods of earthquakes, uplift, knowledge they have gained about geologic time, transformed the deposits into stone. weathering, and erosion reshape Earth’s surface. events to invent a specific event and imagine Ancient seabeds became limestone; mud and themselves in it. clay became mudstones and shale; and river Objective 1: Describe how sand and sand dunes became sandstone. Each weathering and erosion change 3. Future Forecasters - During this activity layer originated from a distinct source and so Earth’s surface. students reflect on what they have learned, differs in thickness, mineral content, color, assess their knowledge, and predict future and eroded appearance. Objective 2: Explain how volcanoes, earthquakes, and changes to the landscape of southwestern uplift affect Earth’s surface. Utah in 100 million years. ThisObjective is a caption 3: Relate for the the building introduc - tion photograph. The bottom edgeup and of breakingthe image down aligns of Earth’swith thesurface baselines over time of the to thelast various lines of textphysical on this land page. features. Fifth Grade Pre- and Post-Visit Activity Guide 1 Tectonics and Uplift continues today along active faults like the In an area from Zion to the Rocky Mountains, Hurricane and Wasatch Faults. Despite the tectonic forces deep within the Earth mountain building and stretching that pushed the surface up creating the Colorado occurred in the surrounding areas, the Plateau. This was not chaotic uplift, but Colorado Plateau rose to its high elevation slow vertical hoisting of huge blocks of the with little deformation. crust. Zion’s elevation rose from near sea level to as high as 10,000 feet above sea level. Erosion Uplift is still occurring. The uplift of the Colorado Plateau gave the streams greater cutting force in their descent For many millions of years, portions of the to the sea. The park’s location on the Pacific Plate (oceanic crust) subducted be- western edge of this uplift caused the streams neath the thicker, more buoyant North to tumble off the plateau, flowing rapidly American Plate (continental crust). This down a steep gradient. These streams began subduction formed mountains and volcanoes eroding and cutting into the rock layers, along the west coast, and led to the formation forming deep and narrow canyons. of the Rocky Mountains. Later, changes in plate geometry led to the end of subduction Grain by grain the Virgin River has carried along much of the West Coast (although away several thousand feet of rock that once subduction continues today in the Pacific lay above the highest layers visible today. On Northwest). Instead of being pushed together, average, the Virgin River transports one the plates began to slide sideways (lateral million tons of sediment per year. The rate motion), as is seen today in California’s San varies dramatically with the flow of the river, Andreas Fault. This lateral motion stretched with the vast majority of sediment transport portions of western North America; creating occurring during floods. When the river is low a region called the Basin & Range. Western- and clear, very little sediment is moving, and most Utah is part of the eastern edge of the much of the transport involves minerals Basin & Range province, where stretching dissolved in the water. NPS/MARC NEIDIG Bridge Mountain Zion National Park. Fifth Grade Pre- and Post-Visit Activity Guide 2 The Virgin River is still excavating. Upstream Pre-Visit Activities from the Temple of Sinawava, in The Narrows, the river cuts through Navajo Sandstone, 1. Earth’s Power Punches creating a slot canyon. At the Temple of Sinawava, the river has reached the softer Duration: 1 Hour Kayenta Formation below. Water erodes the Location: Indoors shale, undermining the overlaying sandstone Key Vocabulary: blind arch, butte, cinder and causing it to collapse, widening the cone, erosion, earthquake, geologic canyon. As the plateaus continue to rise, the processes, mesa, rock layers, uplift, basins drop, and the river cuts, Zion Canyon volcanoes, weathering is expanding upstream at a rate of about 10 miles of lateral movement every million years. Objectives By the end of the activity, students will be able Volcanic Activity to a) name three Earth processes that shape Volcanic vents, created as a result of the the landscape, b) name two Earth processes weakening of the Earth’s crust during tectonic that have helped to change the landscape at events, allowed lava flows and cinder cones to Zion, c) name which Earth processes have form. Cinder was piled several hundred feet occurred quickly and which have occurred high in classic cone shapes and lava flowed slowly. into valleys. Cinder cones and black basalt flows are visible west of Rockville and on the Method Kolob Terrace. Students view a presentation showing geologic processes that contribute to changing Fractures and Faults landscapes. Applying their knowledge to Zion, Fractures and their control of canyon erosion students view images and identify evidence of are one of the most striking features of the geologic forces such as weathering, erosion, canyons of the Virgin River. The fractures (not earthquakes, volcanoes, and uplift. faults because there is no displacement) exert a strong influence on the erosion of smaller Background canyons in the Navajo Sandstone. The Earth’s surface constantly changes due to weathering, erosion, earthquakes, volcanoes, These fractures are believed to have formed and uplift. At Zion National Park evidence of due to tectonic compression and extension these processes is observed in the water and forces. The fractures form perpendicular to wind carved rocks, uplifted geologic the direction of the compression and layers, volcanic flows, cinder cones, mesas, extension. The dominant fracture direction blind arches, and other landforms. in Zion is roughly north-south. There are also fracture sets that are east-west (Kolob Materials Canyons) and northeast–southwest (Kolob • Utah State Geological Survey presentation Terrace and Hop Valley). of Landscapes located at http://geology. utah.gov/teacher/ppt/utah_landforms.ppt While the straight north-south canyons • Zion National Park landscape images on either side of Checkerboard Mesa are located at http://www.nps.gov/zion/ controlled by large fractures, the criss-cross forteachers/loader.cfm?csModule=security/ fractures on its surface are of a more getfile&PageID=541853 recent origin. The horizontal banding is the result of differential weathering of the crossbedded sandstone, while the vertical cracks are thought to be the result of freeze/ thaw cycles at the surface of the rock.