Plate Tectonics Since the beginning of human kind there has been a cloud of wonder of how our planet was formed. Scientist interested in this field through out the years have developed many different theories to how our planet came about. Before the Twentieth Century, scientists and geologists thought that mountain structures were due to the massive tightening of the earth caused by the gradual cooling of molten rocks. In 1900, American scientist Joseph Le Conte, published an article in the Appleton's Popular Scientific Monthly. He described that the problem in understanding mountain building was establishing the cause of sideways pressure. It was not until 1910, that an American Geologist named F.B.Taylor, proposed the idea of a continental drift. Other scientists dismissed Taylor's idea, because there was just not enough proof. However, Taylor's idea was then backed up by a German scientist named Alfred Wegener. He proposed that the continents surrounding the Atlantic Ocean, Africa and South America fit together like a jigsaw puzzle. His broad range of studies enabled him to incorporate his theory of Plate Tectonics. Wegener, later in 1915 while in the German military published his idea that interpreted how his continental drift theory worked. He proposed that a huge landmass called Pangea, meaning ("all land") existed 200 million years ago. He furthered explained that this super continent began to drift apart very slowly throughout millions of years into what it looks like now. Wegener went on several expeditions through out his life to the continents of South America and Africa. He came back with evidence to support his claim of plate tectonics. Wegener and his expedition brought back rock structures, fossils, and evidence of ancient climates. When it came to rock structures, Wegener looked for the similarities of the rocks found along coastlines and the mountain belts found on the continents. They looked at the mountain belts of the Appalachian Mountains and the Caledonian Mountains in Scandinavia and the British Isles. These two continuous belts contained similar rock structures and the ages of these rocks matched the on both ends of the African and South American continents. Wegener also found evidence of massive climatic changes. He researched and found out that ancient glacial deposits were found indicating that ice sheets covered a large part of the Southern Hemisphere, India and Australia. He furthered explained that the Northern Hemisphere was near the equator supporting the idea of coal deposits being located there.
Our understanding of the Earth’s interior has been a focus for scientific study for multiple decades, recognised in the early 1900’s. Throughout the years, scientists have debated and quarreled over their findings, observations and theories for the most correct model of the composition and internal structure of the Earth.
Charles Lyell Charles Lyell was a British lawyer and one of the smartest geologists known at his time. He was known as the author of the Principles of Geology, which helped popularize the theories and concepts of uniformitarianism. The Principles of Geology was the first book written by Lyell and explained the changes in the earth’s surface. He used the research and information in the book as his proof to determine that the earth was over 6,000 years old. The central argument in his book was “the present is the key to the past”, this meant that to find out what happened in the past you had to look at what was happening now.
For example when he writes about how the axes of each continent affects how well ideas and domesticated crops and animals flow or spread through the continent. This discussion had made lots of sense for me and is yet another idea that supports his theory. "At the one extreme was its rapid spread along east-west axes: from Southwest Asia both west to Europe and Egypt and east to the Indus Valley (at an average rate of about 0.7 miles per year); At the opposite extreme was its slow spread along north-south axes: at less than 0.5 miles per year, from Mexico northward to the U.S. Southwest; at less than 0.3 miles per year, " This example shows how east to west axes allow for a faster diffusion of crops and animals. But the north to south is very slow compared to the other. This helps explain why Eurasia had developed the quickest and the America and Africa lagged behind." For example, Portugal, northern Iran, and Japan, all located at about the same latitude but lying successively 4,000 miles east or west of each other, are more similar to each other in climate than each is to a location lying even a mere 1,000 miles due south." This line tells us why Eurasia was able to develop so fast. That is because it has an east to west axes which means animals and crops can more wildly thought the same land due to there being large amounts of land with the same latitude. While the Americas
Palaeogeography deals with the reconstruction of physical geographical conditions for the eras of the Earth's history. The term comes from the Greek παλαιός (palaiós) meaning ‘old’ and γεωγραφία (geōgraphía) meaning ‘a description of the earth’ and seems to have been introduced in the Earth sciences vocabulary as ‘Palaeo-Geographie’ by Ami Boué (1794‒1881), a French‒Austrian geologist, in his publication Einiges zur palaeo-geologischen Geographie (Boué, 1875, p. 2). Palaeogeography focuses on the distribution of land and sea, the spread of mountains and volcanoes and the expansion of glaciations, among others. The results are presented in geographic depictions called palaeogeographic maps. A special kind of palaeogeograpahical map is palaeobiogeographical maps depicting the distribution of
...s from the Paleozoic, Mesozoic, and Cenozoic periods show proof of how animals have gone through evolution and why certain fossils look very similar. The Law of Original Horizontality and the Law of Superposition both express true when looking at modern rock layers today. The Law of Original Horizontality happens when sediments are constantly deposited over old layers of rock forming new layers over millions of years, while the Law of Superposition is the law that older rock layers lie beneath the newer layers. Also, Pangea and Panthalassa are now the seven continents and four oceans of the world today as a result of Continental Drift. All things considered, Rock layers are therefore evidence of Evolution for, rock layers holds proof of evolving animals seen through fossils, the plates in the earth separated Pangea, and the relation of evolution and rock layers.
In 1785 James Hutton could no longer credit what the biblical inscriptions were stating about how old the Earth was, so he decided to try to find out the history and what the true age of the Earth. This breakthrough took two men to complete and justify; uniformitarianism is a “theory that processes that occurred in the geological past are still at work today” (Larsen 2017 pg25). With evidence that Hutton collected, he came to the conclusion that the Earth’s surface changed due to natural forces which include the wind and rain. These changes have been recorded from the multiple layers of rock or the strata, that have been discovered on multiple mountains and canyons. From the different strata’s that Hutton gathered evidence from he was able to, “… calculate Earth’s age in the millions of years” (Larsen 2017 pg24). Although this discovery was forgotten about, it remained and became the work of Charles Lyell, he made it his mission to oversee and confirm that uniformitarianism was accurate. Lyell gathered evidence and personal observations that tested Hutton’s idea in order to prove that it is a theory, which he was able to accomplish.
Tectonic Activity The continents of the world are all separated by different tectonic plates which when collide is called Tectonic Activity. There are different forms of tectonic activity and different processes and landforms, which are involved during and as a result of the collisions. As and when these collisions are going to take place we can't determine because current technology hasn't allowed us to dig as far into the earth to the point of pressures which causes the plates to collide. These pressures are believed to be eruptions of liquid magma deep inside the earth.
Man has believed, for most of his existence, that the earth was only a few thousand years old. But a new theory surfaced in the 19th century called "Uniformitarianism". This is the belief that nature can be explained by natural causes.
regions of the earth can indicate which rock layer is older than the other. Trilobite fossils
The Permian Period was the last period of the Paleozoic Era. During this geological time period’s earlier stages glaciation was extensive. Middle Permian began to warm, and by the late Permian the environment was hot and dry. The environmental conditions were so extreme that the marine and terrestrial life forms were greatly affected. According to research the drastic climate change could have been caused by the formation of Pangaea. In 1912 Alfred Wegener while studying his theory of the continental drift, discovered Pangaea’s very existence. A combination of all of Earth’s landmasses joined together and covered 1/3 of Earth’s surface. Pangaea was f...
The going theory of the First Americans is the ever-popular land bridge hypothesis, which connected Siberia and Alaska. This is believed to have happened at least twice during the ice ages between 32,000 and 36,000 years ago and, again between 13,000 and 28,000 years ago. This repeated connection took place where the eastern and western hemispheres come the closest to one another. The best illustration that I found explaining the land bridge was the analogy made to a seesaw. On one side being the glaciers and on the other side is sea level. When the glaciers get bigger or "go up" the sea level withdraws or "goes down". Basically when all the earth's water is in the form of snow or ice sea level is lowered. At least 180 feet lower to form that Siberian land connection. Direct proof of this...
Although geographers don’t all agree on one theory as to why the ice ages may have happened, there are a couple theories that many believe could have caused the beginning of the ice ages. One of the leading theories for the cause for ice age involves the idea of another theory, the plate tectonics theory, which proposes that the Earth’s surface, which are divided into plates, are constantly moving. The theory suggests that the plates of the Earth moved away from the equator where it is generally warm, and towards a colder place, an area where the sun’s rays were not very strong, which made land very cold. This is a logical theory be...
Earth was formed 4.8 billion years ago (3) . It became the home for hazelnuts because it had an atmosphere and environment which allowed for life to prosper in later years. Earth’s surface was once composed of a single landmass, known as Pangaea (1).Over time it was broken up into seven different plates which were free to move as a result of movements in the hot, semi-liquid magma beneath the...
Thomas Kuhn, one of the most widely recognized contributors to the discipline of the philosophy of science, raises the argument within The Structure of Scientific Revolutions that advancement within the field of science occurs in a revolutionary manner as opposed to one more progressive or cumulative. Kuhn makes the observation that scientific research is conducted cumulatively where every piece of evidence contributes towards gradually understanding a specific scientific phenomenon (Kuhn, 96). However, lasting scientific advancement only transpires when previously accepted scientific theories are overturned with entirely different, more suitable theories. Kuhn makes reference to the Copernican Heliocentric model as an instance to validate his assertion (Forster). Applying Kuhn’s argument to this revolutionary theory will provide clarity and further understanding necessary to demonstrate how this philosophical approach can be applicable towards relatively modern scientific theories such as plate tectonics.
Since this time, the term uniformitarianism has been manipulated, altered, and redefined to mean a variety of different meanings spanning various fields of science. However, in the field of geology, uniformitarianism (or actualism) means something very specific. The term does not denote that every process we see before us now has been going on for eons, rather it stand for the chemical and physical laws that govern today’s processes. Evidence shows that the ancient atmosphere of the earth is extremely different from the one we can see today. There fore, the means by which erosi...