Structural Geology and Plate Tectonics
Geology is an overall study of planet Earth—“its composition, structure, process, and history” (Shipman, Todd, & Wilson 602). Geology also plays a role in the study of the Moon and other solar system objects is primarily the province of astronomy. “None of the remarkable scientific advances of the twentieth century revealed with certainty the composition and structure of the Earth’s interior” (603). Present ideas presently rest on indirect evidence provided by earthquake body waves, their speed and direction identifying the types of materials through which they move, meteorites whose composition is believed to be similar to the Earth’s, spacecraft measurements of gravity and magnetic variations, and laboratory
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Ultramafic rocks have special significance, in that they probably are derived from the mantle. They are relatively unstable on the Earth’s surface, and are typically metamorphosed. In nature and in simplistic interpretation, igneous rocks that make up most continental crust typically have a felsic composition (such as rhyolite and granite). The mafic rock basalt is the dominant rock type that makes up most ocean crust. Rocks of intermediate composition are derived from the mixing of continental and oceanic crust (USGS …show more content…
However, it was not until this century that nuclear age technology was developed that uses measurements of radioactivity in certain types of rocks to give us ages in numbers of years. These ages, usually called radiometric ages, are used in conjunction with relative dating principles to determine at least an approximate age for most of the world 's major rock formations (USGS). “Radiometric dating is the determination of age by using radioactivity, has become geology’s best tool for establishing absolute geologic time” (Shipman, Todd, & Wilson 704). The atomic nuclei that decay of their own accord are said to be radioactive. The decay product—or daughter nucleus, as it is commonly called—may be stable. If so, the transformation reaches completion in a single step. However, the daughter nuclei of many naturally occurring isotopes are themselves radioactive and hence undergo further decay”
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Encyclopaedia Britannica also states that it is “proved to be a versatile technique of dating fossils and archaeological specimens from 500 to 50,000 years old” (1998). This method of age determination is dependent upon the decay of nitrogen and radiocarbon (Carbon-14) (Encyclopaediea Britannica, 1998; Opinions of Radiocarbon Dating, 2011). Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere (Encyclopaediea Britannica, 1998; Opinions of Radiocarbon Dating, 2011) and all living things exchange the gas carbon-14 with the atmosphere surrounding them. The amount of carbon-14 exchanged into the living organism is perfectly balanced with its surroundings, but when an organism dies, they stop taking in the gas and that equilibrium is damaged. Because Carbon-14 slowly decays at a known rate called its “half-life” in a dead organism, scientists can figure out how long ago it had stopped exchanging carbon with its atmosphere. Thus, its age can be determined by measuring the amount of Carbon-14 in a sample (Hirst, 2017; Opinions of Radiocarbon Dating, 2017; Oxford Radiocarbon Accelerator Unit Research Laboratory for Archaeology, n.d.; Earthsky, 2017; Cram, 1993). With the utilisation of Radiocarbon Dating, scientists have been able to discover that Lindow
Patterson determined the age of the Earth using information regarding lead and uranium. Patterson knew the rate of decay of uranium, and he knew
of the effects of plate tectonics acting over geologic time. The story begins with the
Geology is the study of earth surface. Geology deals with the outdoors, which attracts most people. Geology deals with learning about the planets and satellites in the Solar System.
Scientist are able to use modern instruments to accurately date these rocks by measuring radioactive decay. These rocks are approximently 1.7 billion years old, less than half the age of the earth. These black rocks tell scientist not only how old they date back but
L. Vardiman, A.A. Snelling and E.F. Chaffin (Eds.), Radioisotopes and the Age of the Earth: Results of a Young-Earth Creationist Research Initiative, Institute for Creation Research, Santee, California, and Creation Research Society, St. Joseph, Missouri, 2000.
Before the discovery of radiometric methods to determine the age of the Earth, the first few attempts were off by thousands of millions
Relative dating does not establish a specific age of a something. In geology, scientists analyze the rock layers above and below a specific segment of rock to determine its relative age.
The older the fossil the less carbon-14 it contains. But radiocarbon dating can be used to study fossils that are up to about 40,000 years old. For fossils older than this, other method which uses other radioactive elements such as uranium, rubidium, etc. are used. These can accurately determine the age of fossils that are billions of years old.
For millions of years the Earth has experienced geologic catastrophes. Since the existence of Theia itself, the Earth’s crust has been formed, deformed, and even demolished. The crust has never been a completed masterpiece due to this. Why is this? The most recent physical changes were caused by the theory of plate tectonics and earth’s crust displacement. Plate tectonics and its movement resulted in our continents drifting across the earth’s surface, and the creation of mountain belts, volcanoes, and the faults of today’s Earth.
Radiometric dating is a technique that utilizes unstable isotopes of natural elements. Because these unstable isotopes eventually decay at a constant and singular rate despite any environmental changes such as temperature or moisture changes. The unit used as measurement is a half-life which is the amount of time it takes 50% of the original isotope to decay into the next isotope or daughter isotope. Basically the amount of half-lives is multiplied by the length of the half-life to estimate the age of the object being tested. Every element used has a different half-life and that makes each useful for measuring certain types of material. Some have longer a half-life and thus a longer effective dating range. Potassium-argon dating is useful for dating material that is extremely old. This method is used by geologists to replace relative ages based on rock formation with absolute ages. The dates found from the radiometric technique are accurate because the sources, the individual radioactive isotopes, are unchanging and unaffected by environmental factors. This means that the radiometric data will always be precise unlike relative dating which relies on the theory of uniformitarianism, the theory that geological history is made up of endless and uniform
Earth is in fact an intricate planet that has multiple layers of differing compositions. To be exact the earth has four main layers. The uppermost layer is the one humans come in most contact with, the crust. The crust consists of “thin silicate rock material”(Structure of the). Although the crust is not entirely the same. Actually there are two distinct types of crust, oceanic and continental. “The continental crust is made up of mostly rocks similar to granite while the oceanic crust is much denser and made up of a material similar to basalt”(Structure of the, Rose). The second layer is called the mantle. “The mantle is much denser than the crust and contains similar to the crust mostly solid silicate crust”(Structure of the). “As we travel further down the earth we wind up in the outer core. The outer core is a core of molten nickel and iron. Finally there’s the inner core. The inner is a solid metal core made up of nickel and iron”(Structure of the). All these layers functioning together cast out a magnetic
For millions of years, tectonic plates have been determinate of changes in the physical face of the earth, and they continue to do so today. These massive plates move underneath the surfaces of the oceans and the continents, producing earthquakes, volcanoes and uplifts. This paper will discuss the composition, movement and history of tectonic plates, the theory of plate tectonics and its history, and tectonic plates affect the surface of the earth today and will continue to do so in the future.
Fluorine dating is a method is centered on the principle that the element fluorine from the soil is absorbed by fossil bones. The elements fluorine is buried in the soil and therefore the lengthier they are buried, the bones will have more fluorine. However, this method requires several samples taken from an immediate location.