Module 6

Question 1

absolute geologic age

Answer 1

understanding when in time events actually happened

Question 2

relative geologic age

Answer 2

understanding when events happened relative to one another

Question 3

how can you tell the sequence of events in a cross-section

Answer 3

a series of stratigraphic principles

Question 4

principle of superposition (steno)

Answer 4

in any undisturbed series of sedimentary rocks, the oldest layer will be at the bottom, successively younger layers on top

Question 5

principle of original horizontality (steno)

Answer 5

beds of sediment laid down in water form horizontal or near-horizontal layers

Question 6

principle of cross-cutting relationships (steno, hutton, lyell)

Answer 6

a geological feature that cuts across or penetrates another body of rock must be younger than the rock mass penetrated

Question 7

principle of inclusions (lyell)

Answer 7

fragments included in the host rock are older than the host rock

Question 8

what is correlation

Answer 8

determining time equivalency of rock units, and similarity in lithology and/or fossils

Question 9

principle of faunal successions (smith)

Answer 9

fossil species succeed one another in a recognizable order, so we can index fossils to relate to specific time periods

Question 10

example of cross-cutting relationship

Answer 10

portugal

Question 11

example of superposition and original horixontality

Answer 11

grand canyon

Question 12

unconformity

Answer 12

represents a gap in the geological record, that most often is from an erosion surface. There are three types to identify

Question 13

disconformity

Answer 13

layers above and below the unconformity are parallel to one another

Question 14

angular conformity

Answer 14

younger beds overlie tilted or folded beds

Question 15

nonconformity

Answer 15

younger beds overlie much older metamorphic or plutonic (igneous) rocks