The project is located at an elevation of ~730 m above mean sea level and within the Basin and Range physiographic province (BR). The BR is composed of high relief mountains or foothills separated by low-lying valleys and salt flats. The salt flats of the Amargosa do not support plant life, but Phreatophytes (deeply rooted plants) occur on their edges and near the adjacent gravel-dominated alluvial fans. Iodine bush (Allenrolfea occidentalis) grows closet to the salt flats, while saltgrass (Distichlis stricta) and arrowweed (Pluchea sericea) occur more distal. The dominant species in the salt flat-proximal areas is honey mesquite (Prosopis juliflora) that occurs as large stands. Sacatone grass (Sporobolus airoides) and desert holly (Atriplex hymenelytra) intergrown with …show more content…
Miocene volcanic rocks that form the Timber Mountains and Oasis valley caldera complex border the basin to the north (Christiansen et al., 1977) and extend southward beneath the basin. Most of these volcanic rocks are silicic ignimbrites that are 9.5-16 Ma (Christiansen et al., 1977). These volcanic rocks are overlain by moderately to highly deformed siltstone, fanglomerates, tuff, and limestone that have been correlated to the Furnace Creek Formation of Death Valley (Hunt and Mabey, 1966; Naffe, 1973) which has been dated at 5.3 to 6.4 Ma (Fleck, 1970; Hay et al., 1986).
Pliocene to Pleistocene sediments composes the basin fill in the Amargosa desert, with most of the rocks comprising Mg-rich clay deposits of Pliocene age. The exposed parts of the Pliocene basin rocks are dominated by clays and carbonate rocks on the eastern part of the basin with comparatively few outcrops on the western part of the basin. Thickness of the Pliocene sequence may be 300 m thick in the Ash Meadows area (Naffe, 1963) and near the Amargosa project, and is estimated to be 2 to 4 Ma years
The Yellowstone volcano is very active volcanic system which requires much observation. The geysers, mudd pots, hotsprings and steam vents are all examples of the heat from molten rock of a volcano. For many years the Yellowstone volcano could not be located. There is not obvious signs of a volcano, but scientists looked for other clues. Rhyolite is present in a location that has pinetress and many mosquitoes can be found due to the lakes that have formed. Rhyolite is a very violent eruption, due to the high silica content, it flows slowly, like honey, and tends to pile up and form lava
The oldest rocks found in the Death Valley region were formed in the Precambrian time period no more than 1.8 billion years ago during the latter half of the Proterozoic Eon. The rocks are seen on the steep face of the Black Mountains above the current area of Badwater and were formed via deposits of mud and sand from an ancient volcanic mountain belt. Sometime between 1.8 and 1.7 billion years ago, the volcanic and sedimentary rocks were severely altered when chemical or structural changes occurred because of intense heat or pressure from the Earth's core. Because of this process, any fossilized information about the region was lost making it impossible to truly understand the origin of the region. There is some debate on whether basalt or schist was the original and dominate rock in the region before it was transformed into contorted gneiss, but again, there is no way to prove either theory.
The youngest of these rocks are dated at about 220,000 years ago. Rhyodacties and quartz latites in the modern caldera area extruded from about 320,000 years ago to 260,000 years ago, and then silica-rich rhyolites at Glass Mountain northeast of the caldera erupted from about 210,000 years ago to 80,000 years ago. The scattered distribution of the initial mafic eruptions indicates that they were erupted from the mantle, while the slightly younger domes and flows were from a deep-crustal source. The youngest rhyolite eruptions erupted at the northeast rim of the caldera at Glass Mountain and were the first activity of the silicic Long Valley magma chamber (Bailey, et. al., 1989).
The Sierra Nevada, Southern California, Idaho, and Coast Range batholiths formed as a result of which orogeny?
Little Cottonwood Canyon is a site bursting with geological history, rock formations earthquake potential on the fault, prehistoric glacial formations, landslides, and many hazards associated with it. The Wasatch fault is bound to have a enormous earthquake in the future and has left behind numerous scars. The mountains have been engraved by glacial formations dated back to the Ice Age (~14,000 years ago). Rock falls and landslides have left hefty boulders as indication of erosion and moisture in the rocks. The hazards on this mountain range are mass wasting, radon, earthquakes, and flooding of Little Cottonwood Creek.
First, we must examine the sedimentary formations; when they were formed, how they were formed, and what materials they consist of. About ninety-three to one hundred million years ago, the Western Interior Seaway rolled through the North American continent, eventually reaching the geographical area of today’s Mesa Verde National Park (National Park Service 2005). This sea deposited a thick, hard sandstone base that is called Dakota Sandstone, although this layer is not exposed in the park
The state of Texas is the second largest state in the United States. Due to its location and size, it covers different geographical areas and climates. These areas support different ecosystems from deserts to coastal wetlands, with local wildlife varying with the environment. With such varied climates and yearly rainfall, it is easy to have crops growing in the east and little rainfall and an open rocky desert with cacti in the west. The geological history is also varied across the state leading to different mineral deposits by region. It is easy to see that Texas is a state with many unique areas that provide a wide variety of natural resources, native crops, and wildlife.
Weathering, geologic processes such as erosion, and climatic shifts allow for this immense desert ecosystem to continually evolve and change which has taken place for millions of years. This geologically wealthy environment is composed of alternating flat-lying layers of soft and hard deposits of mostly sedimentary rocks. Interchanging slopes and cliffs along the landscape helped form these layers of rock which can be seen fully exposed in areas of the mesa. Deposition of this landscape mainly occurred during the Permian, Pennsylvanian, Triassic and Jurassic time periods. The assortment of warm hues of sandstone were produced by varying levels of iron oxide minerals during formation.
The Raton-Clayton volcanic field is about 20 000 km2 in size, and has been active periodically for the past 9 million years. The area is filled with peaks, cones, and lava-capped mesas. The mesas developed as lava flowed into valleys and depressions, cooled off and formed a resistant top layer over sedimentary rocks. As the surrounding rock eroded, the lava protected the underlying stratigraphy from erosion. This caused todays topography, where that which was once the lowest point, is now the highest. There is some disagreement over why the volcanic field is here, one possible cause is that it is near the end of the Jemez Lineament, which has numerous volcanic centers along its reach, possibly
Lava flows of rhyolite and basalt have flowed through parts of Yellowstone as recently as 70,000 years ago. These lava flows destroyed everything in their paths while moving slowly at a rate of a few hundred feet per day, flowing months, or sometimes even several years. They are thick and cover as much as 130 square miles. They have nearly filled the Yellowstone Caldera, and spilled beyond the caldera’s border. These lava flows are responsible for forming four of the nine named plateaus in
The three national parks are of the same formation. The Sierra Nevada range was contrived from a piece of granite that started from batholith, which is again is something that was structured underneath the earth from a massive pool of magma that cools slowly. Then the shelf was later inclined making the eastern side of the edge lift up by the tectonic activity. In result, when at the Sierra Nevada the slope on the western side is more gradual on than on the eastern side. Death Valley is a graben or rift valley which is depressed blocks adjoined by lateral faults.
The Grand Canyon has plenty of volcanic rocks near the bottom and the top. ICR, Institute for Creative Research, has been involved in a project for years to date these volcanic rocks. this study has come a long way to show that many of the Grand Canyon strata could have formed rapidly, and that the erosion of the Canyon by the Colorado River has not been going on for millions of years.
The defining character of a desert is usually low levels of rainfall with under 25 cm per year. Additional to that, the relationship between rainfall and the evaporated and transpired water must be taken into consideration. “A desert is a biological community in which most of the indigenous plants and animals are adapted to chronic aridity and periodic, extreme droughts, and in which these conditions are necessary to maintain the community’s structure” (Phillips, Comus, 2000, p. 10). This means that it is the environmental and climatic conditions that have created an evolutionary pressure for the flora to develop.
The film shown in class shines light towards the culture of Rwandans and the use of a traditional instrument called the inanga, and the music that is associated with it the inanga is the main instrument featured in the film. It is an instrument used by the Tutsi ethnic group. The film centers on the inanga and a few musicians who are prominent inanga players. This representation differs from how the course is typically presented as the class is given equal representation when there are multiple parties in play. The main ethnic groups in Rwanda, Tutsi and Hutu, have an extremely unpleasant past. The Hutus killed many hundreds of thousands of Tutsi and moderate Hutus. The film is a documentary focusing specifically on the Tutsi way of life, and Tutsi heritage. Although the film centers on, the Inanga it differs from the way information is presented during class; while in the film it only represents one ethnic group in class, multiple viewpoints presented.
Kieffer et al., (2004) studied the petrology, geochemistry, and isotopic compositions of the large shield volcanoes, compared their compositions with those of the flood volcanic and also traced the variations in eruption style and magma flux of lavas with ages ranging from 30 to ~10 Ma, (from the peak of flood volcanism to the onset of major rifting in the northern part of the volcanic plateau).