Relative Dating Essays

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

For example, The appalachian Mountains were formed by a massive continental collision over 300 million years ago. According to page 88 in my science notebook, the rocks in the Chattooga River is evidence of the continental collision. Mountains are formed when two continental plates collide, and form the mountains. The Appalachian mountains, were formed during Pangea. The North American Plate and the African Plate collided. When this happened the Appalachian Mountains were formed. These mountains then grew bigger, but as soon as it started growing, it also eroded. Erosion and

Until the early 1900's, scientists used several methods of measurement in their efforts to determine the age of the Earth. They studied sedimentation and erosion, stratification (with fossil evidence), measured the salinity of the oceans, and used thermodynamics to determine loss of heat since the Earth's beginning. Each of these approaches yielded estimates that the Earth was anywhere from 24 to 100 million years old.

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

Structural Geology – When large bodies of rocks are formed these did not happen in one day. They have history within that can be studied. Structural Geology discovers this history to be able to tell what happened before, what kind of tectonic plate occurred. Structural Geology supports other Geology areas such as Petrology to discover natural gas or petroleum to say the least.

Determine the relative age each of the geologic structures shown in the geologic cross section below (Figure 9.17) from youngest to oldest; then answer the questions below. As before, a wiggly line running across the geologic cross section indicates an unconformity and a fault is indicated with a bold straight line.

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

4. Choose one of the geological periods listed in figure 3.8 and find out all you can about it. How are rock formations from that period identified? What are its most characteristic fossils? Where are the best samples of rock from your chosen period?

The idea that one giant flood is responsible for all the erosional formations on the Earth is a grand assertion which ignores the vast complexity and rich diversity of the Earth’s landscape. The power of water based erosion is responsible for carving landscapes, and the deposition of sediment across wide distances, a process which cannot occur rapidly.

Dating the rocks of the Grand Canyon is a scientific way to find out the age of this mysterious landmark. The age of the Earth and the Grand Canyon is a question both of a biblical interpretation and scientific investigation. It can be viewed by an old earth creationist and young earth creationist. The two creationists have a difference of opinion concerning the formation and age of the Grand Canyon rocks.

The fossils in the lower silty layers were most likely formed below water by normal geological processes. The sea level rose covering the organisms and the layers of silt settled above them. In the upper sandy layers the fossils could have been formed above water by a sudden catastrophic event as a result of ongoing erosive processes. The conditions in which the fossils formed were likely a result of wave action which eroded the coast line until it was unstable. When the sea level receded there was a landslide covering the

Nicolas Steno, a Danish anatomist, geologist, and priest came up with the idea to recognize sequences of historical events in an outcrop of sedimentary rock layers. Steno used the basic principle of superposition which means that each bed sedimentary rock or any kind of rock is older than the bed above. This principle can also be applied to other surface-deposited materials, such as lava flows and beds of volcanic eruptions. By using this principle we can tell if a bed of rock is in its rightful place or if that bed of rock was manmade. Another principle that Steno is credited for is the principle of original horizontality. The principle can be summed up as if rock layers are flat, it means that they have not been shaped up and are original horizontality. However, they are folded or inclined at a steep angle, then they have been moved into that position by crustal disturbances. The principle of lateral continuity, principle of cross-cutting relationships, principle of inclusions and unconformity are other examples of how to tell historical

This method is used to determine the exact age of fossils, artifacts and the earth. This involves, examining several strata of the crust of the earth to show the time intervals of one layer of rock to another layer as well as use the layering principle to confirm the series of cultures.

When we think of history, we think of important people, places, cultures, events, and much more. The backbone of history rests on its chronology. It gives us the "when" of basic analysis. It gives us a frame of reference, the order of things. Before having an "absolute" way of determining dates, history was based in guesses and assumptions. Many attempts were made to organize the dates of the past. Some of these attempts were made by geologist. Geologist used the idea of "stratigraphic succession" (Renfrew, 1973) which is based on the "principle that when successive layers or strata are observed in position, the underlying ones are the earliest." (Pg. 23 Renfrew, 1973) By setting the layers in

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.