GEO PRE Lab-Quiz 12

(Q003) An angular unconformity is evidence that

there is an incomplete geologic record preserved in an area.

(Q005) The principle of inclusions states that

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

(Q009) A nonconformity occurs when

a series of sedimentary rocks sits upon eroded igneous rocks.

(Q002) The numerical age of a sedimentary rock can be determined in the field from which type of feature or characteristic?

a.graded bedding b.the fossils it contains ->c.none of the possible answers are correct.<- d.mud crack orientation

(Q012) The longest interval of geologic time is a

eon

(Q007) If a sequence of sedimentary rocks has been folded and is now vertical,

graded bedding can help determine whether some beds are older or younger than the beds next to them.

(Q008) A disconformity occurs when

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

(Q001) The term relative age refers to

whether a feature is older or younger than another.

(Q006) If a fault offsets a sequence of sedimentary rocks, what must be true about the fault?

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

(Q013) After three half-lives have elapsed for an element, the percentage of parent element atoms present will be

12.5%.

(Q011) A sedimentary rock contains zircon clasts that have been dated radiometrically as ranging from 1 billion to 250 million years old. The oldest that the rock can be is

250 million years.

(Q004) The principle of superposition can be used to determine the relative ages of all of these except

folded sedimentary rocks.

(Q010) In order for a fossil to be used as an index fossil, the species must have existed for a

very short span of geologic time and lived throughout the world

(Q014) The shorter the half-life of a radiogenic element, the more useful it will be for dating

very young events