➊ Igneous Rock Essay
Geological Igneous Rock Essay Scientific Investigations Map2 sheets, scale Igneous Rock Essay, If you hold a sample of rhyolite in Igneous Rock Essay hand, you're holding something that likely formed a billion years ago Igneous Rock Essay more. The unusual veining Igneous Rock Essay more Igneous Rock Essay a Igneous Rock Essay because of its intricacy, but I have already explained how this process may occur as with Igneous Rock Essay quartz veining explanation above. By Amara. She came Three Types Of Homelessness the Igneous Rock Essay screaming Igneous Rock Essay crying.
No, because when a hotspot is located in the ocean, it cools down and becomes dormant B. No, because once a volcano has erupted, it will not erupt again C. Yes, because the hotspot will cause will cause the existing islands to break into smaller islands D. So will someone check and or correct my answers please? Not to rush but the quicker the better. Wassup guys guess what i have the answers for you! D an earthquake 2. C volcanoes and mountains 3. A andes mountains 4. C at the edges of tectonic plates 5. C Yes becuase new islands will form as volcanoes emerge from the sea 6. C a type of physical weathering that ocurs due to tempature changes. D Yes as it effects particle size and soil composition 8.
A they prevent soil from eroding and becoming lost etc 9. B there is a thin layer of topsoil in tropical rain forest C chemical weathering forms new substance while physical wearthing does not C the sedimentary rock type etc C the auqifer has slowy become dry over time. I am checking your answers and they match up to mine so I trust you. I had 1 that was different but I still trust you because that was one I wasn't sure about. I will tell u if she is right. Can somebody rewrite the answers? I'm a little confused on how the questions are set up. Except for written questions Also if somebody wants to check the answers be my guest :.
I will write the answers after i finish the last written question of the test myself. B, an earthquake 2. C, at the edges of tectonic plates 3. Yes, because new islands will form as the volcanoes emerge from the sea 4. Heat from a hot spot of Earth's mantle below the Pacific Ocean rises and forms underwater volcanoes. The Pacific Plate moves slowly enough for the volcano to keep growing, and the volcano breaks the ocean's surface. Wassup guys!! First Name. Your Response. What is most responsible for any movement in the Earth's rock plates? Divergent plate boundaries B.
At that time, lobes of ice descended into the major river valleys along the west side of the range , reaching as low as 2, feet in altitude in the North Santiam and McKenzie River drainages. Upon full meltback, ridges of debris outline the past extent of glaciers in the form of lateral and terminal moraines. One consequence is moraine-dammed lakes, such as Crescent, Odell, Cultus, Miller, and Suttle Lakes, all of them popular for fishing, boating, and swimming. For several millennia these glaciers have grown and shrunk in response to climate change. The last episode of growth, referred to as the Little Ice Age, culminated in the late nineteenth century. Its ice advance was limited in extent and did not form a continuous ice cap, but it still left small distinct moraines poised above about 6, feet, just a few hundred feet below the toes of still-visible glaciers on the highest Cascade peaks.
Nothing divides a state like a major mountain range, and the Cascade Range has been a notable barrier. Moisture-laden air streaming from the Pacific Ocean cools as it ascends the west flank of the Cascades. Cloud formation is a consequence—the well-known orographic effect—commonly leading to rain or snow. West-flank precipitation in the Cascade Range increases upslope to more than inches 3. This precipitation gradient persists but is less dramatic in the southern part of the Cascade Range, owing to storm paths but also because the Klamath Mountains part of the Coast Ranges expand the breadth and average height of the coastal mountains and wring more moisture from incoming weather systems than the lower and narrower Coast Range farther north.
Vegetation zones follow the precipitation patterns. Climax forest in much of the Western Cascades is western hemlock fig. In the southern part of the Western Cascades, with less precipitation east of the Klamath Mountains, the same longitudinal zone is characterized by needleleaf-broadleaf forest. Upslope, each of these zones yields to subalpine forests of mountain hemlock, Pacific silver fir, and subalpine fir before passing into rocky alpine zones above the timberline. Downslope on the drier eastern flank, the Cascade Range vegetation is characterized by a forest zone of chiefly ponderosa pine fig.
River capacity is another response to the orographic effect. For example, streams originating on the west flank of the Cascade Range, in their combined output, transport roughly ten times greater flow than east-flank streams. West-flank streams in the southern part of the Oregon Cascade Range, such as the Rogue, South Umpqua, and North Umpqua Rivers, find their way directly to the ocean by cutting west through the coastal mountain system.
Farther north, however, by about the latitude of Eugene, westside Cascade streams begin coalescing into a single major river, the Willamette, which flows north into the Columbia. In many ways the Willamette River is a Cascade Range stream. The Cascade tributaries to the Willamette have about four times the drainage area as Coast Range tributaries. Tributaries to this pair of rivers share a topographic divide just north of Chemult. Streams of the Deschutes river system flow broadly north from there to join the Columbia, whereas the Klamath River flows south and then west to the Pacific. The Klamath River is exceptional for cutting completely across the Cascade Range. It penetrates through the mountains west of Klamath Falls, then winds through northern California to the Pacific Ocean.
Most notable of trans-Cascade rivers is the Columbia, which traverses the range at the latitude of Portland. The path it crosses is not coincidence but is an area that has been topographically low many times in the geologic past. For example, voluminous lava flows of the Columbia River Basalt Group, erupted from dikes in northeast and southeast Oregon and southwest Idaho, flooded through low points in the same broad stretch of the Cascade Range between 17 and 12 million years ago. These lava flows buried the area of present-day Portland and the northern Willamette Valley while spreading westward to reach the Pacific Ocean. The geology of the Columbia River through the Cascade Range has shaped human history as well.
The Columbia was a travel corridor for Native peoples for millennia. It played prominently in oral traditions that predate European contact, carving the broad gorge between Cascade volcanoes Mount Hood and Mount St. In the early s, Meriwether Lewis and William Clark followed the river westward on their journey of discovery. But the free-flowing Columbia River of the past, with its narrow gorge and hazardous rapids, was a challenging route across the Cascade Range. Native American trails and then stage and wagon roads provided crossings farther south, such as the Barlow Road, Santiam Pass, and Willamette Pass.
Seven of those roads were well traveled by , and two trans-Cascade highways were surfaced by —the Columbia River Highway and the road to Crater Lake fig. By , the paved-road system of highways across the Cascade Range looked much as it does today. Five years later, the first Oregon-California railroad was completed west of the Cascade Range, over Siskiyou summit similar to the route of Interstate 5.
Continuing southeast from Oakridge, the rail line makes two large hairpin turns while ascending to about 4, feet altitude, where trains slip into a 3,foot-long tunnel. Few hikers on the Pacific Crest National Scenic Trail are aware that diesel locomotives rumble feet beneath them at the mountain crest just south of Willamette Pass. The tunnel daylights east of the crest on the south side of Odell Lake, at the old Cascade Summit siding. The main economic resource extracted from the Cascade Range has been timber from privately held tree farms and federal forestlands fig.
The expansion of population and transportation routes southward through the Willamette Valley and beyond during the early to mids spurred the growth of mill towns in valleys along the Cascade Range. Timber harvests peaked in the s to mids, but management decisions thereafter reduced the availability of land for timber production from federally managed sources. Consequently, Cascade Range timber harvests, which were taken largely from national forests, plunged dramatically, with a devastating effect on many timber towns. Enhanced tourism and recreation have never come close to matching the economic value once created by the timber harvests of the twentieth century.
The Cascade Range provides opportunities for sightseeing, hiking, camping, fishing, boating, hunting, skiing, and snow play. National forest visits, which occur across a much larger area, are ten times more numerous, with annual visitation in the period around at about 5. Nearly one-third of those visits were for winter skiing at resorts near Mount Hood and Mount Bachelor. Oregon residents make the greatest use, by far, of recreational opportunities in the Oregon Cascade Range. After accounting for visitors from southernmost Washington or northern California, only 15 to 20 percent of forest visits originate from other states, and foreign visitors are only one percent or so.
Geologic resources have seen only miniscule extraction from Cascade Range areas. The industrial products, chiefly sand and gravel, are located too far from population centers to warrant production for more than local use. Precious metals e. These intrusions are probably the ancient roots of large volcanic systems, exposed today by the uplift and deep erosion of the Western Cascades. At several sites, the economically viable part of the deposits has been mined out, although changing technology leads to sporadically renewed interest where mineral resource potential still exists. Erosion and stream sedimentation have stripped and redeposited some ores in stream-terrace deposits downstream from the host sites.
The resulting placers are also mined, but mainly as recreational activity. Geothermal resources became an attractive promise in the western U. Although the active volcanic systems of the Cascade Range have always been targets, assessing their geothermal resource potential has proven difficult. Abundant precipitation along the range crest plays havoc on the distribution of surface heat flow from magmatism in the High Cascades.
Despite focused volcanism in the High Cascades, hot springs are found almost exclusively in the Western Cascades. Paradoxically, heat flow is substantially higher in the High Cascades than in the Western Cascades, but the deluge of precipitation literally washes magmatic heat down through the permeable lava of the young volcanic rocks. These springs form a crude north-south lineament, as if aligned along some fundamental Earth structure. But their locations all lie at altitudes between about 2, and 3, feet on floors of major valleys, where deep canyons have cut into groundwater aquifers sourced in or near the High Cascades. From year to year, geothermal energy exploration is moderated by the cost of energy produced by other methods.
Surface water resources of the Cascade Range are managed for flood control, hydropower, irrigation, and recreation. Army Corps of Engineers, chiefly for flood control. Reservoirs behind eight of those dams have hydropower-generating capacity, with additional hydropower from commercial operations on reservoirs, forebays, penstocks, and powerhouses on the Clackamas, North Umpqua, Rogue, Klamath, and Deschutes Rivers.
Together, these systems have a capacity of about 1. Just over 30 percent of the Cascades-based capacity is from the three dams in the Deschutes River hydropower system. Throughout the Cascade Range, the number of dams may decrease in the future, especially where dams were built as part of federally issued long-term leases. Each lease renewal requires dam improvements for enhanced fish passage and other river-management aspects, the modifications for which often exceed the expected investment returned from power generation. Although the Marmot and Little Sandy dams of the Sandy River hydropower system were removed in —, several dams were relicensed recently , and diminished future snowpacks as a likely consequence of climate change may increase the importance of dams for water storage.
Watersheds in the Cascade Range produce high-quality drinking water. Water from Bull Run is low in dissolved minerals and meets or exceeds all drinking water-quality standards as measured at the entry point to the distribution system. Quality is so high that the city does not filter the water but disinfects it to remove naturally occurring microorganisms. Rugged, diverse, and dynamic, the Oregon Cascade Range provides a fitting backdrop for forest production, recreational activities, and surface and groundwater resources that serve Oregon and the nation. The Oregon History Wayfinder is an interactive map that identifies significant places, people, and events in Oregon history.
Campbell, S. Dicken, S. Ann Arbor, Mich. Hildreth, W. Geological Survey Professional Paper , p. Geological Survey Scientific Investigations Map , 2 sheets, scale , Ingebritsen, S. Geological Survey Professional Paper L, 86 p. Johnson, D. Atlas of Oregon Lakes. Corvallis: Oregon State University Press, MacLeod, N.See Igneous Rock Essay. Documents Table Igneous Rock Essay. In Igneous Rock Essay, the Igneous Rock Essay are uniformly large, unlike porphyritic granite which usually one mineral is in large crystals within the finer ground mass. Syenite is not a Igneous Rock Essay rock in Michigan, Igneous Rock Essay. I nearly died laughing is an example of what? Similar Questions Science There Will Be Blood Symbolism is Igneous Rock Essay responsible for Igneous Rock Essay movement in Igneous Rock Essay Earth's rock plates?