Question 1 5 out of 5 points The single word which is the familiar label for the mainstream geologic perspective that "The present is the key to the past" is _________ Selected Answer: uniformitarian ism Correct Answer: Evaluation Method Correct Answer Exact Match uniformitarianism Question 2 5 out of 5 points Explain what is meant by the quotation in question #1. Selected Answer: Changes in the Earth's crust during geological history resulted from the action of continuous and uniform processes. Observation can be used to predict future geologic events. The future will resemble the past. Correct Answer: Uniformitarianism is the view that geologic processes observed today, both in type and in their speed (called "rate" in geology), are the same as those that operated in the past. For example, if erosion is removing an inch per year from a mountain now, then erosion in the past did the same; this allows an estimate of the mountain's age. Generally, catastrophic changes, when rates and even processes themselves are radically different from those at present, are excluded by uniformitarianism. Today, most geologists allow for a mix of uniformitarian processes and a number of catastrophes in Earth history. But in all perspectives about Earth history, the underlying Laws of Nature are held to be constant, without change. Response Feedback : [None Given] Question 3 0 out of 5 points There are several kinds of unconformities. Identify the particular kind that applies to the following description: The presence of a mild or extreme erosional boundary between (otherwise generally parallel) sedimentary strata is an example of a/an ___________________ . Selected Answer: discorda nt Correct Answer: Evaluation Method Correct Answer
Exact Match disconformity Exact Match disconformities Response Feedback: Not angular unconformity, because the strata are parallel. Not nonconformity, because the strata above and below are both sedimentary. Question 4 6 out of 6 points Name at least two methods for correlating strata that are far apart horizontally and impossible to trace from one location to another. Selected Answer: Lithologic correlation which uses physical and chemical characteristics to determine spatially isolated strata to be continuous. Fossil correlation uses fossils with known stratigraphic ranges to determine temporal equivalence of two bodies of rock. Correct Answer: 1. Comparison of the stratigraphic sequences; in particular, the sequences of types of rock in vertical order. 2. Comparison of the fossil assemblages in the stratigraphic sequences.
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- Spring '14