If you order your research paper from our custom writing service you will receive a perfectly written assignment on How Do We Calibrate the Geological Time Scale?. What we need from you is to provide us with your detailed paper instructions for our experienced writers to follow all of your specific writing requirements. Specify your order details, state the exact number of pages required and our custom writing professionals will deliver the best quality How Do We Calibrate the Geological Time Scale? paper right on time.
Our staff of freelance writers includes over 120 experts proficient in How Do We Calibrate the Geological Time Scale?, therefore you can rest assured that your assignment will be handled by only top rated specialists. Order your How Do We Calibrate the Geological Time Scale? paper at affordable prices!
In the calibrating of the Geological times scales, two methods are used. One is the measurement of relative time and the other is the radioactive decay of an element. The measurement of relative time is based on the fact that sedimentary rocks are deposited in layers, younger above older, and contain fossils that are of distinctive ages. Whereas radioactive decay is based on the radioactive decay of an element. Because a specific radioactive element decays into a specific stable element at a known rate, both can be used to measure absolute time, the age of objects in years. Then the Geological Time Scale is calibrated.
By determining the relative ages of rocks in one locality or region and then comparing or correlating them with those of other regions, geologists can establish the chronological ordering of geologic events in the Earths history. This is done by studying the formations of rocks, observing the principle of original horizontality (which states that sediments are deposited parallel to the Earths surface), observing to the principle of superposition (which states that each layer is younger than the layer beneath it and older than the one above it), studying the unconformity between the layers of formation (angular, nonconformity, and disconformity) and the principle of cross-cutting relationships (which states that a fault or intrusive body must be younger than the rocks it affects).
Geologists can also tell a great deal about the history of rock formations by observing their unconformity. An unconformity is an erosion surface between layers of markedly different ages. In angular unconformity, the strata rest upon the upturned edges of the strata beneath. In nonconformity, strata rest on eroded metamorphic or igneous rocks. A disconformity is an irregular contact between parallel strata. By observing these and those principles listed above, geologist can determine a lot about earth's history.
Correlation is the process of demonstrating age equivalence. There are three methods of local correlation lateral continuity, physical similarity, and similarity of sequence. Fossils are used to correlate widely separated rocks.
Write a research paper on How Do We Calibrate the Geological Time Scale?
Yet another tool used to correlate fossils and strata is the principle of faunal succession. This principal states that fossil assemblages succeed one another in an orderly fashion. Therefore, matching fossil assemblages can correlate strata of the same relative age.
Superposition and the fossil record form the basis of the relative geologic time scale, the events of the Earths history used in chronological order, Strata from various localities constitute standard sections for given intervals of the relative geologic time scale. Index fossils are useful in correlation because they have narrow ranges wide geographical distributions. The relative time scale is divided into eons, eras, periods, and epochs, order of decreasing magnitude. For example, the Phanerozoic eon is divided into Paleozoic, Mesozoic, and Cenozoic eras. The Precambrian comprises percent of the geologic time scale.
To determine absolute age, geologists use radioactive atoms that decay at a steady pace over long periods. The process by which unstable atoms emit or capture subatomic particles is called radioactive decay. There are three forms alpha decay, beta decay, a beta (electron) capture.
As a result of radioactive decay, a parent isotope is eventually turned into a stable (non radioactive) daughter product. The age of a sample is determined by the ratio of parent to daughter and by known decay rate. The decay rate is expressed in terms of the half-life of the parent, the time it takes for half (50 percent) of the remaining parent to decay.
The effective time range is the interval over which a radioactive isotope yields useful dates. Some radioactive isotopes used in dating are uranium-5 and uranimum-8, which decays to lead-07 and lead-06, respectively; potassium-40 which decays to argon-40; and rubidium-87, which decays to strontium 87. The 570-year half-life of carbon-14 makes this isotope extremely useful for dating relatively young materials of organic origin. This is how the Geological Time Scale is calibrated.
Dolgoff, A. (18). Physical Geography. New York, New York Houghton Mifflin Company.
Please note that this sample paper on How Do We Calibrate the Geological Time Scale? is for your review only. In order to eliminate any of the plagiarism issues, it is highly recommended that you do not use it for you own writing purposes. In case you experience difficulties with writing a well structured and accurately composed paper on How Do We Calibrate the Geological Time Scale?, we are here to assist you. Your persuasive essay on How Do We Calibrate the Geological Time Scale? will be written from scratch, so you do not have to worry about its originality.
Order your authentic assignment and you will be amazed at how easy it is to complete a quality custom paper within the shortest time possible!
