Geology (Term Paper Sample)

Name
Geology 1022:
7th Feb. 2014
Assignment #1
1 Numeric dating is a scientific approach of determining possible age or rocks and other sediments by studying the radioactivity behaviour of the rocks. Ideas about decomposition rates of radioisotopes is the basic principle behind this kind of dating. Relative dating on the other hand involves use of observable futures to make assumptions on possible age of rocks. For instance, the strata layers can be dated according to their position on earth’s crust. Numeric dating is more pronounced for igneous rocks while relative dating is preferred for sedimentary rocks.
2 Principle of cross cutting relationships. Using this principle, we study the position of a fault cut in relation to the sediment beds. The principle states that faults that occur after deposition appear to have been broken layers. However, if tilting occurred before deposition, the tilted cuts will be unbroken.
3 Index fossils are decayed, once living, species that were believed to exist in certain geological times. When we find such fossils on rock strata, we can compare the position of the fossil relative to the strata. It is expected that the extinction dates of the index fossils are known. One can then say a strata is of the same age as the fossil if it is found lightly embedded on it. Also, when several strata layers are found on over the index fossil, one can conclude that the strata is younger than the index fossil thus a formation date can be postulated. Whenever we have more than one index fossil, a more elaborate dating procedure will be carried out since their position relative to the strata is the guiding principle.
An example of index fossil is the Trilobites believed to be 500 million years old. If we find this embedded in a strata, then the strata is likely to be more than 500 million years old.
4 Currently there are no complete geological columns. However, According to Morton (2001), geological columns have been found to exist. An example is the North Dakota geological column. Today, geological columns have been viewed more theoretical than as a series of rock layers. A complete sequence does not exist however for the available ones seem broken. We always expect a total of 12 columns to make a complete geological column. Some argue that earth degradation processes as erosion are responsible for wiping out other layers that will provide full evidence. A lot of controversy still exists in the issue as it draws conflict between those who believe in biblical creation theory and geologists.
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Correlation is a process of studying stratigraphic records seeking for specific clues and evidence to match rocks. It entails a deep study of parameters to try and determine rocks with similar formation periods even if they are located in different positions. Fossils stand out as powerful correlation tools because of the following reasons:
* Similar fossils can be found in various positions thus used to compare age of rocks
* Fossils have distinct extinction times and thus approximation of ages can be made easily
* Fossils are restricted to limited thickness of a given strata, thus, it is limited in age ranges
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Igneous rocks- radiometric dating involves studying a rocks particles and using radioactive techniques of half-life to determine the age of a rock. Since igneous rocks have fine grained particles that are similar in characteristics, the dating is accurately achieved for a larger piece of igneous rock. Metamorphic rocks also have relatively small particles although the process is not recommended. Sedimentary rocks cannot be dated using this method because the particles are very large, and it would mean conducting tests on every crystal.
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* What is the new atomic number of the atom (after that loss)?5
Since the atom lost two protons, the new number of protons will be:
10-2=8
Atomic number corresponds to number of protons, thus the new atomic number is 8
* What is the new atomic mass number of the atom (after that loss)?5
Atomic mass number = Mass of protons + mass of neutrons
= 8+10 (since no neutrons are lost)
= 18
* 200,000b. 50,000c. 100,000d. 25,000