Earth sci chapter notes for quizzes

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Earth sci chapter notes: Chapter one Summary: In Europe, scientific investigation was not well-coordinated or disciplined until the late 19th century. There were competing methods, theories, and systems, and science was intertwined with alchemy, folk tales, and religious dogma. Greek and Medieval philosophy aimed to connect scientific speculation with the divine structure of the universe, subjecting scientific ideas to religious scrutiny. However, independent thinkers began to challenge this traditional approach. In the 18th century, geology posed a threat to religious dogma by introducing the concept of evolution and the process of change. Nicolaus Steno, a Danish natural philosopher, studied the Earth's surface and developed hypotheses to interpret geological history. His work marked the beginning of modern geology. Thomas Burnet, an Anglican clergyman, interpreted creation literally and attributed the Earth's uneven features to Noah's flood. Steno's work was overshadowed by Burnet's initially, but today Burnet's books are considered pseudoscience. Answers: 1. What were they famous for? (e.g., who was the father of geology?) - Nicolaus Steno  Nicolaus Steno is considered the "father of stratigraphy" and made significant contributions to the interpretation of geology.  He is considered one of the pioneers of modern geology and is often referred to as the "father of stratigraphy," which is the study of rock layers and sediments.  Steno's work was groundbreaking because he approached the study of the Earth's surface in a logical and systematic manner. He observed various geological processes such as weathering, sediment transport, and the formation of layered sediments in lakes. Based on these observations, Steno sought to understand the history of the Earth's surface and how it had changed over time. - James Hutton:  James Hutton is considered to be the father of modern geology.  James Hutton, a Scottish geologist and physician, is famous for his contributions to the field of geology and his theory of uniformitarianism. In the context of the article, Hutton's ideas challenged religious dogma and had revolutionary consequences for both religion and society.  Hutton's theory of uniformitarianism proposed that the Earth's geological processes have been occurring gradually and uniformly over long periods of time. This theory contradicted the prevailing belief in catastrophism, which suggested that geological changes were the result of sudden and catastrophic events, often attributed to divine intervention. - Thomas Burnet:  Thomas Burnet was famous for his work on the interpretation of the Earth's history and its relationship to religious beliefs. In the article, it is mentioned that Burnet, an Anglican

clergyman, assumed a literal translation of creation as told in the Bible. He believed that the uneven features of the Earth's surface resulted from Noah's flood, which he believed came from inside the Earth and subsided back there when the flood was over.  Burnet published four volumes of his ideas, which were considered pseudo-science mumbo- jumbo by modern standards. However, during his time, his work was praised by influential figures like Isaac Newton and many clergy members. - Charles Lyell:  This geologist built strongly on Hutton’s work on the theory of uniformitarianism and further popularized the concept of uniformitarianism in his own influential work, "Principles of Geology,". Lyell was true. brilliant man, and an amazing speaker, and his public lectures were always filled. - James Ussher:  James Ussher was famous for his work in the field of chronology and biblical studies. He is particularly known for his attempt to calculate the age of the Earth based on the genealogies and events mentioned in the Bible. Ussher's most famous work is "Annals of the World," in which he meticulously calculated the dates of biblical events and concluded that the Earth was created on October 23, 4004 BC.  In the context of the article, Ussher's work is relevant because it highlights the influence of religious dogma on the study of science during the time period discussed. The article mentions that there was no separation between science and religious beliefs, and Ussher's calculations exemplify this connection. His work was widely accepted and praised by the clergy of his time, demonstrating the influence of religious authority on scientific investigations.  However, it is important to note that Ussher's calculations have been widely criticized and are not considered scientifically accurate today. The pursuit of scientific investigation has since evolved, and the methods used to evaluate scientific theories have become more rigorous and evidence based. - Cuvier:  Cuvier became famous for his work on the sedimentary rocks of the Paris Basin and his interpretation of the geological formations found within.  Cuvier's study of the sedimentary rocks in the Paris Basin led him to recognize a repeated series of layers consisting of boulders above layers of fine-grained sands. He interpreted this as evidence of repeated stages of sudden flooding that had affected the region. Moreover, he proposed that these flooding events were caused by a series of huge catastrophes, which were sudden, violent, overwhelming in force, and completely unpredictable. Cuvier associated the final flooding event with Noah's flood and linked earlier flooding events to mythological accounts of great floods from various ancient cultures.

 Furthermore, Cuvier's interpretation of the geological processes extended beyond the Paris Basin. He consistently attributed the final geologic process to Noah's flood, while allowing for variations of earlier catastrophes in other regions. This perspective led Cuvier to accept sedimentary rock layers containing fossils as evidence of extinct animals that had perished in global and catastrophic floods. - William Smith:  William Smith: He was a canal engineer who noticed that individual layers in sedimentary strata contained distinct characteristic fossils. He was the first to identify the same layer in different parts of the country based on its fossil content. This observation led to the development of the Principle of Faunal Succession, which states that fossils can be used to determine the relative age of sedimentary layers. Smith's work allowed geologists in the 19th century to assemble a stratigraphic column of younger-upon-older strata, which helped understand the order in which sedimentary layers had been deposited. - Henri Bequerel:  Henri Bequerel: In 1896, Bequerel discovered that some atoms of certain chemical elements, such as uranium, are inherently unstable and undergo predictable breakdown, a property known as radioactivity. This discovery paved the way for modern estimates of absolute time and the determination of the age of Earth. By studying the decay of radioactive elements, scientists can establish absolute age dates for rocks and minerals. 2. What did each of them believe in terms of how nature works: Catastrophism vs. Uniformitarianism? - Catastrophism:  Steno's work was influenced by the concept of catastrophism, which suggests that Earth's geological features were primarily formed by sudden and violent events or catastrophes.  Cuvier's beliefs aligned with the catastrophist viewpoint prevalent during his time. As a catastrophist, he held the following beliefs: the history of Earth was a record of unique events, there was no natural evolution of anything (biological or inorganic), and it was impossible to predict nature.  Archbishop Ussher believed that nature worked in accordance with a literal interpretation of the Bible. He conducted extensive calculations of births and deaths mentioned in the Bible, as well as examined other official documents, to determine that the Earth came into existence at sunset on October 22nd, 4004 B.C. Ussher's findings were used and misused for centuries, despite the limited scientific facts available to him at the time. - Uniformitarianism:

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 Burnet, on the other hand, believed in a form of uniformitarianism, which suggests that Earth's geological features were formed by gradual and ongoing processes over long periods of time.  Charles Lyell was a proponent of uniformitarianism rather than catastrophism. During Lyell's time, there was no consensus on how scientific theories should be evaluated, and scientific investigation was not a well-coordinated, disciplined activity. The pursuit of scientific investigation in Europe was influenced by various methods, theories, and systems, and there was no clear separation between science and religious dogma.  Hutton's ideas were shaped by his observations of the natural world and his understanding of geological processes. He believed that the Earth was constantly undergoing changes and that these changes occurred over long periods of time. Hutton proposed the concept of uniformitarianism, which states that the same geological processes that we observe today have been shaping the Earth's surface for millions of years. 3. Define Catastrophism and Uniformitarianism: - Catastrophism: Catastrophism is the belief that Earth's geological features were primarily formed by sudden and violent events or catastrophes. - Uniformitarianism: Uniformitarianism is the belief that Earth's geological features were formed by gradual and ongoing processes over long periods of time. 4. Explain the theories of Catastrophism and Uniformitarianism: - Catastrophism: The theory of catastrophism suggests that major geological changes occur as a result of sudden and catastrophic events, such as floods, earthquakes, or volcanic eruptions. These events were believed to have shaped the Earth's surface and caused the formation of mountains, valleys, and other geological features. - Uniformitarianism: The theory of uniformitarianism proposes that the geological processes that shaped the Earth's surface in the past are the same processes that are still occurring today. It suggests that the Earth's features were formed over long periods of time through gradual processes like erosion, deposition, and uplift. 5. Examples of what a catastrophist versus a uniformitarian believes: - A catastrophist would believe that the Grand Canyon was formed by a catastrophic event, such as a massive flood, that rapidly carved out the canyon. - A uniformitarian would believe that the Grand Canyon was formed over millions of years through the gradual erosion of the Colorado River. 6. Identify one or more problems with either of these theories:

- Catastrophism: One problem with the theory of catastrophism is that it does not account for the vast amount of time required to form certain geological features. It also does not explain the absence of evidence for catastrophic events in the geological record. - Uniformitarianism: One problem with the theory of uniformitarianism is that it assumes that the rates of geological processes have remained constant throughout Earth's history, which may not always be the case. It also does not account for the occurrence of rare and catastrophic events that can have significant geological impacts. Chapter two The age of the Earth and the oldest materials: To determine the age of the Earth, scientists have used various methods and evidence from the geological record. One of the oldest materials found on Earth is meteorites obtained from primitive asteroids. the oldest mineral (incorporated inside a rock as it formed) is a crystal of zircon, and it dates from 4.404 billion years. These meteorites represent material that formed as the Solar System first began to take shape. The age of these meteorites has been consistently measured to be 4.567 billion years, which provides a rough estimate of the age of the Solar System itself. When it comes to the age of Earth, scientists look at meteorites as a reference because Earth gradually accreted from the same solids that compose these meteorites. While we may not be able to precisely determine how long it took for Earth to form, it is estimated to be around 4.54 billion years ago. This estimation is based on the average age of meteorites, which is 4.54 billion years. The principles of stratigraphy: Stratigraphy is the study of rock layers and their formation. There are five fundamental principles of stratigraphy that geologists use to understand the relative ages of rocks and the events that occurred during their formation: 1. Principle of Original Horizontality : - This principle states that sedimentary rocks are originally deposited in horizontal layers. If we observe rocks that are tilted or folded, it indicates that some geological forces have acted upon them after their formation. 2. Principle of Superposition : - According to this principle, in an undisturbed sequence of sedimentary rocks, the oldest rocks are found at the bottom, while the youngest rocks are found at the top. This principle allows geologists to determine the relative ages of rocks based on their position in the rock sequence.

3. Principle of Lateral Continuity : - The principle of lateral continuity states that sedimentary rock layers extend laterally until they thin out or reach a barrier. This principle helps geologists correlate rock layers across different locations. 4. Principle of Cross-Cutting Relationships : - When a geological feature, such as a fault or an igneous intrusion, cuts across existing rock layers, it is younger than the rocks it cuts through. This principle helps determine the sequence of events in a geological area. 5. Principle of Faunal Succession : - This principle is based on the observation that fossil assemblages change through time. By studying the fossils found in different rock layers, geologists can correlate and date the rocks based on the fossils they contain. Summary :  By applying these principles, geologists can create a composite geological column that represents the relative order of rock layers and the events that have shaped the Earth's surface over geological time. This composite column helps scientists understand the Earth's history, including the timing of geological events, changes in climate, and the evolution of life on our planet. It's a valuable tool for reconstructing the past and studying the processes that have shaped the Earth's surface. Unconformities: An unconformity is a gap in the geological record where there is a discontinuity in the sequence of rock layers. It represents a period of erosion or non-deposition. There are three main types of unconformities: 1. Angular Unconformity : This type of unconformity occurs when horizontally layered rocks are tilted or folded, eroded, and then covered by new horizontal layers. The angular unconformity represents a time gap between the older tilted/folded rocks and the younger horizontal layers. 2. Disconformity: A disconformity is an unconformity where there is a gap in the rock record between parallel layers of sedimentary rocks. The layers above and below the disconformity are parallel, indicating a period of erosion or non-deposition.

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3. Nonconformity : A nonconformity occurs when sedimentary rocks overlay older igneous or metamorphic rocks. It represents a significant time gap where the older rocks were uplifted, eroded, and then covered by younger sedimentary layers. Scientists in the chapter and composite geological column:  The article mentions that there are more scientists introduced in the chapter, building upon the list from Chapter 1. While the specific names of these scientists are not provided, it is important to understand their contributions to the field of geology and how they have contributed to our understanding of the Earth's history.  The principles of stratigraphy, as mentioned earlier, allow geologists to form a composite geological column. By studying the different rock layers and their relative ages, geologists can create a timeline of Earth's history. This composite geological column helps us understand the sequence of events that have occurred over millions of years. Time divisions and the appearance and disappearance of fossils: In this stage of the course, it is not necessary to know the names of different geological eras or periods. However, it is important to understand how time divisions were designated based on the appearance and disappearance of fossils. Fossils provide valuable information about past life forms and their distribution in the rock layers. By studying the fossils found in different rock layers, geologists can determine the relative ages of the rocks and establish a timeline of Earth's history. Isotopes and half-life:  An isotope is a variant of an element that has the same number of protons but a different number of neutrons. Isotopes of an element have the same chemical properties but different atomic masses. For example, carbon-12 and carbon-14 are isotopes of carbon.  Half-life is the time it takes for half of the radioactive isotopes in a sample to decay. Radioactive isotopes are unstable and undergo radioactive decay, transforming into other elements over time. By measuring the ratio of parent isotopes to daughter isotopes in a sample and knowing the half-life of the radioactive isotope, scientists can determine the age of rocks or organic matter. Relative and absolute age dating:  Relative age dating : Relative age dating involves determining the relative order of events or objects. It relies on the principles of stratigraphy and the study of rock layers to establish the

sequence of events. Relative age dating does not provide an exact age but helps understand the relative timing of events.  Absolute age dating : Absolute age dating, on the other hand, provides a numerical age for rocks or organic matter. It relies on techniques such as radiometric dating, which uses the decay of radioactive isotopes to determine the age of a sample. Absolute age dating provides more precise and accurate ages but requires specific isotopes and measurement techniques.  Both relative and absolute age dating techniques are still useful today and help scientists understand the Earth's history and the timing of geological events. Chapter 3 Plate Tectonics Introduction: o For geological engineers, plate tectonics is important because it explains, in large part, why and where significant deformation. of Earth’s surface occurs (thus where not to build bridges, for instance). To economic earth scientists, it explains the type and location of many metallic mineral deposits. It explains the global distribution of earthquake and volcanic hazards, although the timing and magnitude of natural disasters are a bit trickier! Continents, ocean basins, and mountain ranges – all are produced by plate tectonics. 2.0 Early Development of the Theory 2.1 Continental Drift: o The theory of plate tectonics was assembled by a number of scientists working over many years. The first steps toward formulation of a theory were made by Alfred Wegener; he grouped his ideas under the heading ‘continental drift’ and published them in 1912. o He figured the fit was so good, that coincidence was impossible. Add to that the wonderful fit of glacial terrain of continents in the southern hemisphere when those land masses were fitted together (Fig.2), the continuity of old geological structures and fossil stratigraphy from continent to continent (Fig.3), and Wegener had some pretty strong ideas to sell. o In the early 1940s, during the war, it became thoroughly obvious there was a need to detect both sunken ships and lurking submarines, so very sensitive magnetometers. o Following the war, two lines of research (one to hunt for natural mineral resources, and the second simply to map the geographic and geologic features of ocean floors) began to produce

the first comprehensive maps of the ocean floors (Fig.5). This work began in the late 1940s and through the 1950s. In the Atlantic Ocean, the most amazing discovery was the definition of a huge volcanic ridge that extended right from the far north and connected with other similar ridges in the far south. Not only that, but it was also discovered that the volcanoes defining the ridge were active for almost its whole length – the largest volcanic system anyone had ever seen. Harry Hess: o In 1960 Harry Hess, a professor at Princeton University, conjectured that these ridges represented spreading centers where Earth’s crust was moving in opposite directions like conveyor belts (Fig.6), allowing new ocean floor to be built from volcanic rock at the ridges. He calculated that, because of this activity, the Atlantic Ocean was widening by about 2.5 cm/year (about the same rate that your fingernails grow). If you took that rate and worked backward, North/South America and Europe/Africa were in contact some 180 million years earlier.

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