Question

2. A break in time in continuous sedimentary rock layers that is due to erosion is called?

a. Siccar Point

b. Contact

c. Unconformity

d. Eon

3. What do we use to numerically date rocks?

a. Radioactive isotopes

b. Minerals

c. Fossils

d. Acid

4. Regarding principles used to determine relative age, what does "Cross Cutting Relationships" recognize?

a. The layers at the bottom are older

b. The layers at the top are older

c. Layers go one horizontally forever

d. The rock that is cut into is older

5. What is something that you could use to correlate rock layers to each other across large areas?

a. Fossils

b. Limestone

c. The Upside Down

d. Silica

6. What's the element that's mostly used to radiometrically date rocks?

a. Uranium

b. Carbon

c. Silicon

d. Hydrogen

7. What's a Half-Life referring to?

a. It's another term for hobbits.

b. It's half the time it takes for magma to cool into a rock.

c. It's the time it takes for a given amount of radioactive isotope to be reduced by half.

d.It's half the time it takes for a bone to fossilize.

8. The concept of: "The present is the key to the past" is called what?

a. Catastrophism

b. Uniformitarianism

c. Relative Age Dating

d. Numerical Age Dating

9. When did the dinosaurs go extinct?

a. About 650,000 years ago

b. About 4,500,000,000 years ago

c. About 65,000,000 years ago

d. About 12,000 years ago

10. How many times does 1000 fit into 1 million?

FYI, 1000 is only 0.1% of 1 million.

I'm just trying to bang into your head just HOW BIG 1 million is.

a. 1000

b. 10

c. 100

d. 1

Answer 1

Answer 2: Option c - unconformity, is correct. An unconformity in a sequence of strata depicts a period of erosion of the lower strata before the upper strata was deposited.

Option a is wrong because Siccar point is a promontory found in Berwickshire that is popular for having the Hutton's Unconformity but it is not the correct answer.

Option b is wrong because a Contact can be any contact between two strata formed by erosion, intrusion, deposition and even a period of non-deposition. It is not restricted to “erosion” as the question states.

Option d is wrong because Eon is a term used to classify time in geology. Other such terms include Eras, Epochs etc.

Answer 3: Option a- Radioactive isotopes, is correct. Numerical dating is an absolute dating method used to give the exact age of a rock strata. This is done by using a variety of radioactive elements like uranium, lead etc and studying their decay in the rock body.

Option b is wrong because minerals are naturally occurring rock compositions that are not specific to absolute dating.

Option c is wrong because fossils actually are only used for relative dating or for determining a range of period. They cannot be used to give a precise numerical date of the strata in which they are found.

Option d is wrong because acid can only be used to see if the rock that it is poured on has carbonates in its composition since acids cause carbonate rocks to effervescence.

Answer 4: Option d, the rock that is cut into is older, is correct. The law of cross-cutting states that if one rock strata intrudes another, the rock strata intruded will always be older. This is one of the laws of stratigraphy used for relative dating.

Option a is wrong because this statement satisfies the Law of Superposition that states that in an undisturbed sequence of strata, the layer on top is younger than the layer below.

Option b is wrong because this is also part of the Law of Superposition.

Option c “layers go horizontally” is a part of the Law of Uniformitarianism that states that the same processes that occur today responsible for shaping the Earth have been occurring throughout its past. Thus these processes apply for the entire Earth.

Answer 5: Option a Fossils, is correct. Fossils are used to correlate specific strata in different core samples or stratigraphic sequences. This goes in line with the Law of Uniformitarianism.

Option b is wrong because Limestone itself does not have a specific place in geology i.e it can be formed in similar environments anywhere on the planet. However, if it is a specific type of limestone that is unique, then we can use it for correlation but that is not accounted for in this question.

Option c is wrong because Upside Down is a term used for a sequence of strata that is turned (younger below and older at top) due to processes like folding and subsequent erosion.

Option d is wrong because Silica is not itself a distinguished composition that can be used for correlation. In the earth’s crust, after oxygen, silica is the most abundant element.

*Post other questions individually.