Knowledge Survey Questions - Petrology

Bloom's Taxonomy Level - 1

• What are the properties of the REE that give them their unique chemical behavior?

Bloom's Taxonomy Level - 2

• Briefly, describe the average composition of continental crust and three ways that this can be estimated.
• Describe the evidence for a change in the composition of continental crust through time.
• Describe how the mineral textures of an igneous rock be used to infer its origin.
• Why are the peak metamorphic conditions of a rock commonly preserved?
• What is a mineral paragenesis?
• Explain how geothermometers and geobarometers work.

Bloom's Taxonomy Level - 3

• Provided a metamorphic rock, determine its metamorphic grade and facies.
• Use the IUGS classification system to classify igneous rock samples.
• Use the trace element and isotope compositions of a suite of rocks to infer their origin and evolution.

Bloom's Taxonomy Level - 4

• Why are shales regarded to be 'representative' of average continental crust?
• Why are chondrites typically used for normalization of REE data? What other normalizing compositions might be used, and when would you use them?
• How would your recognize crustal contamination in a basaltic magma?
• What is an ophiolite? Describe its composition, structure, and origin.
• Compare the metamorphic conditions observed with depth in an accretionary wedge with those in an arc.
• Construct a table that compares the characteristics of magmatism in a variety of tectonic settings. You should select at least one criterion from each of the following categories: petrography, rock types, major element chemistry. Also choose three other criteria that you think are diagnostic. For each of these three additional criteria, also note why you think that criteria is significant.

Bloom's Taxonomy Level - 5

• Formulate a plan for estimating the average composition of continental crust in Minnesota.
• Draw a plot showing the abundances of the elements in the solar nebula. Make sure that key features of the diagram are clearly indicated. Classify the elements on the diagram according to their origin. How are the trends in abundance reflected in the composition of various terrestrial reservoirs?

Bloom's Taxonomy Level - 6

• Evaluate the different models of crustal growth rates through time.
• What is the theoretical base of phase diagrams? How can they be applied to natural rocks? What are their limitations and benefits?
• Evaluate the argument that "dating methods utilizing radioactive isotopes are unreliable because different isotopic systems often yield different ages for the same rock."