One of the reasons is that the Appalachian Mountains act as a dividing line separating the Midwest territory of the US from its eastern seaboard via the Eastern Continental Divide, which traces a path alongside the Appalachian Mountain range starting from Pennsylvania leading up to Georgia. There are also other important roles that the Appalachian Mountain range play and it can be socially, economically and geographically.
Another important characteristic that is attached to the Appalachian Mountains and it formation is that it marked the beginning of plate collisions which was in turn responsible for the building of several mountains and mountain ranges in the planet, and this mountain building phenomena was believed to be responsible for the creation of Pangaea (Klyza and Trombulak 14). Because of the importance of the Appalachian Mountain range, studies on its geological aspect have been undertaken for years now.
The Appalachian Mountains is believed to have undergone a series of different physical transformations and the movements that the Appalachian Mountains experienced throughout its history and creation have made it what it is today. Like other mountain ranges in the world, the Appalachian Mountains, at various times through ages, have risen to great heights from the sea or have been continental rock covered by shallow oceans (Adkins 49). The geological history of the Appalachian Mountains is a very important and very interesting topic to delve on.
Because of this, the focus of the paper is centered in discussing the different aspects of the changes that happened on the Appalachian Mountain ranges, from its creation, the timeline involved and the processes that shaped the formation of the Appalachian Mountains from the start until today. When did they form? Most experts believe that the geology of the Appalachian Mountain ranges goes as far back as nearly 500 million years ago, particularly around 480 millions years ago. The timeline of the formation of the Appalachian Mountain ranges involved the changes that happened in several different eras.
According to professionals, as far back as the Paleozoic Era there were already movements happening in the natural rock formation of the planet that lead towards the creation of the Appalachian Mountain ranges. This was particularly in the eras Ordovician Period which was believed to be the time where rock movements led to the rising of the Appalachian Mountain ranges and its transformation from an erstwhile buried state, being submerged underwater during earlier times (Geologic Provinces 3).
After the Paleozoic Era, there were still changes that affected the Appalachian Mountains. During the Triassic Period of the Mesozoic Era, structure and feature changes affected the creation of Appalachian Mountains, and some uplifting in the rock formation during the Cenozoic Era also contributed to some of the changes that happened in the Appalachian Mountains (Geologic Provinces 8). How did the Appalachian Mountains Form?
The Appalachian Mountain range is a very complex and very old natural geological feature of the planet. The physical characteristics of Appalachian Mountains provide the observer with hints and clues towards how the Appalachian Mountain range was formed and what processes were involved in the formation of this particular mountain range. A major characteristic of its geology is the presence of elongate belts composed of marine sedimentary rocks, volcanic rocks, as well as parts of an ancient ocean floor.
These are all impacted by thrust faulting and folding processes that shaped the Appalachian Mountain ranges from how it was during its initial formation up to how it is now after years of constant transformation owed to the natural rock movements that impact natural geological formation of rocks on the planet (Adkins 50). Before it would rise up and become a mountain range, the region where the Appalachian was to rise from was considered as a passive plate margin.
Because of this, there are times when the area is found underwater, buried by sea water under a sea that was nonetheless shallow, especially since there were also periods where it was above water. The Appalachian region would not remain passive forever, and the change from being passive to being active happened during the Ordovician Period, wherein plate motion movements changed and paved the way for the Taconic orogenym or what is known as mountain building event, in this case the first during the Paleozoic Era.
By this time, the Appalachian is already considered as a plate boundary that is very active in its movements (Geologic Provinces 3). The Iapetus, another oceanic plate situated close to the Appalachian, was considered to collide against the Appalachian. Because the collision eventually sank, it submerges itself under the craton of North America. Because of what was happening in Appalachia and what has happened in the Iapetus, there was a resulting creation of what is known as the new subduction zone.
The creation of this new particular feature was believed to be the birth of what would be known today as the Appalachian Mountain ranges (Chapter 2: Plate T-11. Appalachian Mountains 11). The Taconic orogeny was not the first mountain building plate collisions that helped create and develop the Appalachian Mountain Ranges, because there are still a series of other plate collisions that is set to happen that impacted mountain building, particularly the building of the mountains of the Appalachians.
Several other orogenies, like the Caledonian orogeny, the Acadian orogeny, the Quachita orogeny, the Hercynian, orogeny as well as the Allegheny orogeny all contributed to the mountain building process that shaped the Appalachian Mountain ranges (Chapter 2: Plate T-11. Appalachian Mountains 5). As the Appalachian Mountain range was developing through the years, experts believed that at one point, it was standing as high as, or even higher than the height of the present day Himalayas.
This is largely because of the consistent collision of ancient continents that pushed the mass of land upwards and raised mountains like the Appalachian higher and higher. The activity in the rock features shaping and re-shaping several geological features like the Appalachian mountain ranges experienced change, leading towards being still once again after the Pangea continent started to break apart during the Mesozoic Era. After this, erosion took over, and the once towering Appalachian was transformed into a vast plain.
But this situation would not remain permanent. There were new waves of uplifting that would affect the region in the near future following its transition towards becoming a vast plain, and the uplifting allowed the Appalachian to rise up again, particularly during the Cenozoic Era (Geologic Provinces 7). What Geologic Processes were Available for the Formation? There were several geological processes that contribute to the shaping of the features of the Appalachian mountain ranges and the creation of the Appalachian mountain range itself.
The most important perhaps is the plate collisions, which pushed the rocks upward to create the mountain range. Erosion was also part of the history of the formation of the Appalachian Mountain ranges. It comes into play during the time when the Appalachian region was flattened, a temporary state since the mountains will eventually be a towering feature again in this area after activity in rock movements resume and allowed the Appalachian mountain range to rise up. Other geological movements, like thrust faulting, are also at play throughout the history of the Appalachian mountain range.
Criticisms Despite the presence of the theory on how the Appalachian Mountain ranges was created, there are still criticisms that challenge existing belief by providing newly discovered data involving the geological events and changes directly involved in the shaping and re-shaping the Appalachian Mountains. This is normal especially since the information on the Appalachian mountain range formation is not yet set on stone especially since there are still gapping holes that are not closed because of the absence of solid proofs to support scientific claims.
One of the criticisms was raised in 2006 after scientists believed that they have found new evidence that can change how experts look at the formation of the Appalachian mountain ranges. According to an Ohio University professor, the ocean involved in the collision that started the creation of the Appalachian mountain ranges was not Iapetus but rather Rheic (Ohio University 7), which was believed to have been closed down after the collision between Gondwana and North America, leading to the formation of Pangea and the creation of Appalachian Mountain ranges (Ohio University 8).
There are also those which point to other assumptions involving the Appalachian mountain ranges. Some believe that there were other mountain ranges and chains involved or interconnected with the Appalachian mountain ranges during the millions of years of its rise and erosion. What is today traditionally called the Appalachian Mountains really represents several different mountain chains, formed at different times over a span of at least 130 million years (Klyza, Trombulak 14).
But despite the criticisms, the study and understanding of the Appalachians contribute significantly in scientific study. The scientific attitude and approach towards understanding and studying tectonics as well as mountain-building was developed largely by the efforts to study the Appalachian mountain ranges. Other plate tectonic concepts, even those that involve the studying of how oceans open and close before, was also influenced significantly by the study on Appalachian mountain range formation (Chapter 2: Plate T-11. Appalachian Mountains 3). Conclusion
The history of the Appalachian Mountain ranges is something that is eventful and important today because it is significantly important to other important aspects of world history, like the formation of super-continents and its breaking apart, influencing the geography that modern world has today. Understanding this phenomenon may not be as easy but modern literature is growing and growing to provide more information about this aspect. Works Cited Adkins, Leonard M. Appalachian Trail: A Visitors Companion. Menasha Ridge Press, 1998. Chapter 2: Plate T-11. Appalachian Mountains. National Aeronautics and Space Administration. 6 October 2008.
25 February 2009