Physical Geology - Online Lab Quiz 06

The numerical age of a sedimentary rock can be determined in the field from the fossils it contains. graded bedding. mudcrack orientation. none of the above

none of the above

An angular unconformity is evidence that the local rocks contain fossils. there is an incomplete geologic record preserved in an area. igneous rocks have intruded sedimentary rocks and metamorphosed them. lava flows have erupted onto sedimentary rocks.

there is an incomplete geologic record preserved in an area.

The shorter the half-life of a radiogenic element, the more useful it will be for dating very young events. very old events. sedimentary rocks. faults.

very young events.

A nonconformity occurs when rocks have been folded and eroded before deposition of a younger layer of sediment. rocks have been tilted and eroded before deposition of a younger layer of sediment. there has been some uplift and erosion but no folding between deposition of rocks above and below the nonconformity. a series of sedimentary rocks sits upon eroded igneous rocks.

a series of sedimentary rocks sits upon eroded igneous rocks.

A disconformity occurs when rocks have been folded and eroded before deposition of a younger layer of sediment. rocks have been tilted and eroded before deposition of a younger layer of sediment. there has been some uplift and erosion but no folding between deposition of rocks above and below the disconformity. a series of sedimentary rocks sits upon eroded igneous rocks.

there has been some uplift and erosion but no folding between deposition of rocks above and below the disconformity.

After three half-lives have elapsed for an element, the percentage of parent element atoms present will be 75%. 50%. 25%. 12.5%.

12.5%.

The longest interval of geologic time is a year. era. eon. period.

eon.

In order for a fossil to be used as an index fossil, the species must have existed for a very long span of geologic time and lived throughout the world. very long span of geologic time and lived in a very small geographic area. very short span of geologic time and lived throughout the world. very short span of geologic time and lived in a very small geographic area.

very short span of geologic time and lived throughout the world.

The term relative age refers to ages of siblings and cousins. how many years ago a particular geologic feature formed. whether a feature is older or younger than another. the difference in years between the ages of two features.

whether a feature is older or younger than another.

The principle of inclusions states that all factors must be included in evaluating the relative age of two materials. a sedimentary rock must be younger than the clasts that it contains. an igneous rock must be younger than the rocks it cuts across. fossils must be older than the rocks in which they are found.

a sedimentary rock must be younger than the clasts that it contains.

If a fault offsets a sequence of sedimentary rocks it must be older than the rocks based on the principle of superposition. older than the rocks based on the principle of inclusions. younger than the rocks based on the principle of cross-cutting relationships. none of the above: it could be older or younger depending on the kind of fault

younger than the rocks based on the principle of cross-cutting relationships.

A sedimentary rock contains zircon clasts that have been dated radiometrically as ranging from 1.0 billion to 250 million years old. The oldest that the rock can be is 1 billion years. 500 million years. Correct Answer 250 million years. 50 million years.

250 million years.