Geologic History Review

Question 1

Half life is 1000 years. What is the age of the sample represented by the diagram?

Accepted Answer

2000 yrs

Question 2

Which isotope is used to date organic material?

Accepted Answer

Carbon

Question 3

A fossil is 11,400 years old (C-14). What's the total amount of original C-14 still present?

Accepted Answer

25%

Question 4

What is a characteristic of a good index fossil?

Accepted Answer

Lived for short time and widespread

Question 5

In which NYS landscape region is the trilobite fossil Cryptolithus found in?

Accepted Answer

Tug Hill Plateau

Question 6

Which graph best represents the radioactive decay of C-14?

Accepted Answer

D

Question 7

What fossil group does the fossil manticoceras belong to?

Accepted Answer

ammonoids

Question 8

Which two letters represent bedrock of the same age?

Accepted Answer

D and H

Question 9

Which sequence shows the order of Earth's geologic eras from youngest to oldest?

Accepted Answer

Cenozoic -> Mesozoic -> Paleozoic

Question 10

Which event occurred earliest in geologic history?

Accepted Answer

Abundant eurypterids

Question 11

Which index fossil has been found in SIlurian-age bedrock?

Accepted Answer

D

Question 12

What is the name of the feature shown by line AB?

Accepted Answer

Unconformity

Question 13

What percentage of Earth's history represents human existence?

Accepted Answer

Less than 1.0%

Question 14

What's the largest sized particle that can be found in sandstone?

Accepted Answer

.2 cm

Question 15

Scientists believe that Earth's early atmosphere changed in composition as a result of...

Accepted Answer

Appearance of oxygen-producing organisms

Question 16

A sample has about 12% of its original C-14. What is the age of the sample?

Accepted Answer

17,100 yrs old

Question 17

Layers of volcanic ash often serve as useful geologic time markers because...

Accepted Answer

they deposit quickly over a wide area

Questions 17