Chronology and time scales

Question 1

Relative ages

Answer 1

Based upon order of formation

Qualitative

Question 2

Absolute ages

Answer 2

Actual number of years since event

Quantitative

Question 3

Tools for determining relative age

Answer 3

uniformatization ,superposition, original horizontality, continuity, cross cutting relationships, inclusions, baked contact

Question 4

Uniformitarionism

Answer 4

The present is key to the past

Question 5

Horizontality and continuity

Answer 5

settle out of fluid by gravity

settle horizontally

Question 6

Superposition

Answer 6

an undeformed sequence of layered rocks

Each bed is older than the one above

Question 7

Three types of unconformity (3)

Answer 7

Angular unconformity
non-conformity
disconformity

Question 8

Angular unconformity

Answer 8

deformed by orgogenesis
Mountains eroded completely away Renewed marine invasion
New sediments deposited

Question 9

Non-conformity

Answer 9

igneous/metamorphic rocks capped by sandstone

Question 10

Disconformity

Answer 10

parallel strata bounding nondeposition
interruption by sediment
pause in deposition
sea level pauses

Question 11

fossil range

Answer 11

first and last appearance

Question 12

fossil correlate strata

Answer 12

1) Regional
2) Globally
3) locally

Question 13

Types of stratiographic correlations (2)

Answer 13

1. Lithologic correlation

2. Fossil correlation

Question 14

Lithologic correlation

Answer 14

Regional

sequence - in the order the rocks occur

Question 15

Fossil correlation

Answer 15

Based on fossils within the rocks

Question 16

Eons

Answer 16

largest subdivision

hundreds to thousands of years

Question 17

Eras

Answer 17

subdivisions of an eon

65 - hundreds Ma

Question 18

Periods

Answer 18

Divisions of an era

2-70 Ma

Question 19

Epochs

Answer 19

divisions of a period

.011 - 22 MA

Question 20

Time classifications

Answer 20

Eon : largest
Era
Period
Epochs : Smallest

Question 21

Names of Eons (4)

Answer 21

Phanerozoic
Proterozoic
Archean
Hadean

Question 22

Phanerozoic

Answer 22

visible life” (542 Ma to present)
appearance of hard shells
diversity quickly over time

Question 23

Proterozoic

Answer 23

” before life” (2.5-0.542 Ga)
build up of O2
increased photosynthetic organisms
plate boundary formations

Question 24

Archean

Answer 24

“ancient” (3.8 to 2.5 Ga)
birth of continents
earliest forms of life

Question 25

Hadean

Answer 25

“Hell” (4.6-3.8 Ga)

formation of oceans and secondary atmosphere

Question 26

Names of eras (3)

Answer 26

1. Cenozoic
2. Mesozoic
3. Paleozoic

Question 27

Cenozoic Era

Answer 27

“recent life”

65Mya to present

Question 28

Mesozoic Era

Answer 28

“middle life”

251-65mya

Question 29

Paleozoic era

Answer 29

“Ancient life”

542-251mya

Question 30

Isotopes

Answer 30

same number of protons but different number of neutrons

Question 31

Fusion

Answer 31

coming together of particles

Question 32

Fission

Answer 32

splitting apart of particles

Question 33

Radiometric dates

Answer 33

give the time a mineral began to preserve all atoms of parent and daughter isotopes
- requires cooling below blocking temperature