Geography Questions - Case Study Example

Geography Questions Q1. Why the Amazon River reversed the direction of its flow in the last 200 million years According to Prince the Amazon River currently discharges about 200,000 cubic meters of water per second making it the largest in the world (101). Its distant origin comes from glacial streams in the Peruvian Andes. It has a series of contributors. This mighty river flows from the west towards the east through Brazil. It then empties its waters to the Atlantic Ocean. One interesting fact however is the discovery that the River reversed its direction of flow 200 million years ago. This means that it used to flow from east to west. The change in the direction of flow is attributed to the past fusion of various continents making up the world. This is referred to as the Gondwana. Prince states that during this time, the origins of these river were found in Africa. There are several proofs and evidence to back up the claim (104). The major one is the sediments found in the current river that have their origin in the eastern regions. This implies that Amazon was flowing westerly into the Pacific Ocean. This flow was cut short when Andes Mountains were uprooted. It occurred as a result of the collision between the South America plate and the Nazca. After the collision, there was an upcoming ground that blocked the river from both sides. To the east of the ground was the African origin river and to the west was the Andes that also prevented further flow. As time passed by, sediments that were running off Andes formed a very large swamp like fresh water lake. Later on, the river started to flow in the opposite direction that is currently known today. The rise of the Andes did not only result in this reversal of the flow. It caused another important aspect of the Amazon. As the sediments ran off from Andes, they moved into the waters of the newly created swamp like lake and into the river basin (Prince 102). This resulted in the waters containing very huge amounts of mud composition. The mad was so thick that one had to dig about 200 meters to get even a single rock in the basin. These layers also encouraged the new direction of flow that was now the opposite of what had earlier been there. Q 2. Why oil formations of Brazil duplicate similar ones in Nigeria Geological studies have revealed that the oil formations in Brazil duplicate those found in Nigeria. This is very interesting owing to the fact that the two nations lie in two different continents. Brazil is found in South America while Nigeria is found in Africa. This similarity is attributed to the continental drift. This theory was developed by Wegener in 1992 and it suggested that the continents of the earth used to be together forming a single large mass of land referred to as Pangaea. It later divided into two supercontinents called Gondwanaland and Laurasia. Gondwanaland later on broke to from the continents of South America, Africa, and Antarctica. On the other hand, Laurasia broke up to from Europe, North America and Asia. This is the origin of the relation between the oil formations in the two countries. However, it does not indicate how the continents moved away from each other resulting in various geological activities that formed the oil reserves in Brazil and Nigeria. Prince states that the plate tectonic theory suggests that the plates that made up the crust of the earth were always in motion relative to each other causing geological processes (32). Some were sliding under the other while some moved past the other. Collisions also occurred as the plates moved resulting in interactions with unique geological consequences. Since Brazil and Nigeria were in similar plates the geological processes leading to formation of the oil reserves were similar. Several evidences have been brought forward to show that South America and Africa could have been joined to each other. They explain why the formation of oil in the two countries took similar paths. Alexander Von Humboldt, a German geographer traveled in various parts of the coastal Brazil and Nigeria to collect plat and animal specimen. A lot of similarities were observed. In other studies and analysis, it has been found that the coastlines of West African countries and that of South America appear to be a perfect fit indicating that they were once a single plate. The coastal configuration of Brazil perfectly fits into that of Nigeria despite the fact that the two countries are in two different continents that are miles apart (Prince 34). Similar Studies that have been done along the Brazilian and Nigerian coastlines have indicated similar patterns in the mountains. In Brazil it has been established and observed that the mountains and ranges come close to the coastline. The same case applies in Nigeria. This can only be the case if the mountains had been adjoined together prior to the separation. Therefore, it can be concluded that as the two continents separated and moved away from each other, similar geological processes were initiated resulting in similarity in some of the oil formations and reserves in the two countries. Q 3. Formation of oil and natural gas deposits in the eastern foothills/valleys of the Andes The eastern foothills of the Andes in the Amazon Basin is very rich in oil reserves. Almost all of the Brazil’s oil is found in this region. Other nations bordering it also have their in the eastern basins of the Amazon. This is attributed to the rift formation processes that took place millions of years ago as the various plates moved. According to Prince, rift formation was a very important aspect of plate tectonics (66). It divided several plates into two. After the separation of the continents, the rifts caused more divisions in the region. The collision of the continental and the oceanic plate in the South America region resulted in the creation of the rift in the area this forming an oil rich basin. When the collision occurs, the oceanic plate that was denser overrode the thicker and less dense continental plate. The oceanic plate was then forced to move downwards into the mantle through a process referred to as seduction. It continued to descend into the higher temperature environments where these materials reached their melting points and begin to melt (Prince 64). When this took place in the South American coastline region, magma chambers were produced. The less dense magma begins to ascend slowly above the overlying materials. As the oceanic plate moved down by seduction, it carried with it millions of plans and animals while hard been in the ocean several millions of years ago. The plants and animals had absorbed the suns rays and energy when they lived and stored the carbon molecules in their bodies. This layer of sediments made up of microscopic creatures was therefore forced into a region in the crust with very high temperatures (Prince 67). As the pressure and heat increased with continued seduction, the materials became oil and natural gas in the regions where they had been deposited along the eastern regions of Andes. After the creation of the oil and natural gas inside the crust, they stated to migrate through the overlying material and tiny pores in the surrounding rocks. Some of the oil and gas migrated and moved up to the surface where they escaped. Some was however trapped below impermeable rock layers where they formed the gas and natural oil deposits in the region today. Work Cited Prince, Neville. Major Impacts and Plate Tectonics: A Model for the Phanerzoic Evolution of the Earth’s Lithosphere. London: Routledge, 2011. Print. Read More