Geological Principles: Principle of Superposition: In a sequence of sedimentary

Question

Geological Principles:

Principle of Superposition: In a sequence of sedimentary rock layers, each layer must be younger than the one below.

Principle of Original Horizontality: The surfaces on which sediments accumulate are nearly horizontal, therefore layers of sediment are also nearly horizontal when originally deposited

Principle of Original Continuity: Sediments generally accumulate in continuous sheets that are continuous laterally.

Principle of Cross-cutting Relations: If one geologic feature (dike, fault, erosional surface) cuts across another, the feature that has been cut must be older.

Principle of Inclusions: A rock unit that is included within another rock is always older. If a layer of sediment overlying an igneous rock includes pieces of the igneous rock, the sedimentary layer must be younger. If an igneous intrusion contains fragments of another rock (xenoliths), the igneous intrusion must be younger.

Principle of Faunal Succession: Fossil fauna (animals) and flora (plants) follow one another in a definite, recognizable order.

1. Arrange the labeled (A-G) units and features (rock strata, intrusions, faults, and erosional surfaces, tilted strata, etc.) in a sequence from oldest to youngest event. Create a simple list (table) of the sequence by arranging the letters from oldest to youngest event.

2. For each labeled unit or feature (A-G), determine what your justification is for its order in the relative dating sequence is by selecting one of the geological principles listed above (1-6) that matches the logic that was used to identify the order of events. List the justification (number) next to the letter for the event in your table. Note: you may not need to use all the principles listed above and some of the principles will be used multiple times to explain the sequence of events. Include the table at the start top of your submission.

3. Write a 200 word (or more) essay that briefly explains the sequence of events in your list and discusses how you applied the specific geological principle to determine the sequence of events. In your essay, provide a plausible description of the sequence of events. Include within your essay some information about the type of features you observed in the cross section. For example, identify all types cross-cutting features, such as faults, plutons, and erosional contacts. While composing your essay, consider the following: if we knew that the unit labeled F was dated to be approximately 11 million years old and the unit labeled B (an igneous pluton) was approximately 50 million years old, how would this help us to determine the ages of some of the other units in this figure? Include your thoughts about the answer to this question in your essay.

Explanation / Answer

1) First Rock deposited, a period of erosional and non depositional,strata tilted and fault form and intrusion takes place.

2) principal of stratigraphy, principal of original horizontalality,prin princ of original continuity, principal of cross cutting relationship.

3)First of all sediment deposited According to principal of original horizontalality these sediment deposits always in horizontal way with continuously if there is no major break in deposition takes place.If there is period of non deposition and erosion found there will be unconformity found.Uncoformity shows that after the deposition of sediment there is a period of non deposition and erosion found.After that deformational activity takes place like fold fault and tilt strata found and intrusion takes place .

If given that fault takes place at 11 ma and intrusion takes place at 50ma it means that after intrusion of magma rocks goes deformational stages like faulting and folding.

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