- Learning Goal You Will Investigate Sediment Formation In Yosemite Valley California And Consider The Evolution In Size 1 (63.08 KiB) Viewed 34 times
- Learning Goal You Will Investigate Sediment Formation In Yosemite Valley California And Consider The Evolution In Size 2 (26.52 KiB) Viewed 34 times
- Learning Goal You Will Investigate Sediment Formation In Yosemite Valley California And Consider The Evolution In Size 3 (37.16 KiB) Viewed 34 times
(b) How would you describe the sorting of sedimentary grains in the rockfall deposit? Use the terms in Fig. 6.16A (c) How would you describe the shape of sedimentary grains you can see in the rockfall deposit? Use the terms in Fig. 6.168 movement (d) If the sediments in the rockfall deposit were lithified together as they currently rest, without any further move downslope, what kind of sedimentary rock would they form? 2. Tributary stream just downslope from rockfall deposit (Photo C). (a) The large sedimentary grains that can be seen in the stream channel are generally less than-1.5 m in diameter. Judging from the turbulence of the mountain stream, what grain sizes do you expect to be carried (suspended) in the water? (b) What grain sizes do you expect to be rolling, sliding, or resting on the bottom of the channel, including those that you can see? (c) How would you describe the shape of the sedimentary grains you can see in or near this stream channel (Fig. 6.168) 3. River deposits exposed in the eroded bank of the Merced River (Photo D). (a) List all of the grain sizes that you see or that are likely to be present in the Merced River bank shown in photo D (b) How would you describe the sorting of sedimentary grains in the stream bank? (c) How would you describe the shape of sedimentary grains you can see in the stream bank?
(d) If the sediments in the stream bank were lithified, what kind of sedimentary rock would they form? (e) How would you describe the change or evolution of sediments between the tributary streams and the main Merced River? 4. Use your observations to make predictions. The Merced River flows from Yosemite Valley at an elevation of -1,200 m above sea level in central Yosemite Valley to an elevation of -250 m where the river enters Lake McClure, a reservoir in the San Joaquin Valley west of Yosemite Valley. The actual distance the river travels along its channel from Yosemite to the upper end of Lake McClure is more than 65 km. You can examine the Merced River course between latitude 37.72°N, longitude 119.63 W (central Yosemite Valley) and 37.602°N, 120.100 W (inlet to Lake McClure on the Merced River) using Google Earth. (a) What sedimentary grain sizes are likely to be deposited in Lake McClure from the erosion of Yosemite Valley? (b) What do you think will be the composition of most of the sedimentary grains deposited in Lake McClure from Yosemite Valley? B REFLECT & DISCUSS Based on your work, write a brief description of how the clastic sediment from Yosemite Valley might change as it travels downstream to Lake McClure. Then describe how you could use these insights to interpret clastic rocks in general.