Science 8
Lab: Geologic Time
Name:
Period:
Try to write down the time (years ago) and major form of life or event for each card in the walk.
Scale:
Precambrian Supereon
Paleozoic Era
Phanerozoic Eon
Mesozoic Era
Cenozoic Era
Periods
21
Quaternary
20
Neogene
19
Paleogene
2.6 mya Ice ages, rise of human ancestors, humans
23 mya First apes. Grasses become abundant.
66 mya Mammals become dominant. Alps, Himalayas, Andes Mtns
18a Major mass extinction, linked to asteroid impact, near Yucatan peninsula, Mexico.
18
Cretaceous
145 mya First flowering plants, angiosperms. Large dinosaurs.
17
Jurassic
201 mya First birds, dinosaurs dominate.
16
Triassic
252 mya First dinosaurs, First mammals, Pangaea breaks apart.
15a Earth’s greatest mass extinction at the end of the Permian. Several poss. causes
15
Permian
299 mya First archiosaurs. Large herbivores and carnivores.
14
Pennsylvanian
323 mya First reptiles, coal swamps.
13
Mississippian
359 mya First land vertebrates, coal swamps.
12
Devonian
11
Silurian
443 mya First boney fish, corals abundant
10
Ordovician
485 mya First land plants, first jawed fish.
9
Cambrian
541 mya First animals with hard parts. Trilobites & brachiopods.
419 mya First insects, First amphibians, First trees.
8a
End of Precambrian Time, the “Cambrian Explosion”
8
635 mya First good fossils of metazoans, multi-cellular life. Still rare fossils.
7
1.2 bya Oldest dated rock in South Carolina, Pickens County, Bad Creek.
6
1.8 bya First more complex life, eukaryotes with an organized nucleus.
5
3.2 bya First stromatolites (layered algal and sediment mounds)
4
3.6 bya Oldest definitive microfossils, single cell, prokaryotes
3
4.0 bya Oldest dated rock, oldest probable microfossils.
2
4.4 bya Oldest dated mineral grain, zircon, in another rock.
1
4.6 bya Estimated time of formation of the Earth, entirely molten.
Lab: Geologic Time Walk
2/8/2016
Science 8
Lab: Geologic Time and History
Name:
Period:
Objective: To demonstrate the length of geologic time and to aid in understanding the order of geologic and biologic
events.
Materials: event cards, meter stick, 10 meter length of string or rope with knots at 1 meter intervals, area for a long
walk.
Procedure:
Using the scale of 1 meter representing 10 million years, the length of geologic time will be demonstrated with
cards at the correct points to show the events in Earth’s history according to the fossil and rock record.
Questions:
1. How many years does 1 decimeter (0.1 m) represent? 1 million years
2. How many years does 1 decameter (10 m) represent? 100 million years
3. How many years does 1 millimeter represent? 10,000 years
4. Which is the longest named unit of geologic time? Precambrian time
5. Which is the shortest geological era? Cenozoic Era
6. Which era do we live in? Cenozoic Era
7. Describe the length of time that humans have been on Earth compared to the length of geologic time.
200,000 years/4.600,000,000 years = 0.0000434 or 0.00434 %
8. Describe the length of time that there has been civilization on Earth compared to the length of time that the
dinosaurs were on Earth.
11,000 years/186,000,000 years = 0.0000591 or 0.00591 %
9. Why do we know the most about only the last 540 million years of Earth’s history?
That is when life first developed hard parts making fossilization much more likely.
10. What is the Law of Faunal Succession?
The Law of Faunal Succession states that for all around the Earth in layers of undisturbed strata there is
always the succession of fossils. For example, from fish to amphibians to reptiles to mammals. They
never first appear all at once together or in a different order.
11. What impressions and conclusions can you draw from today’s activity?
Lab: Geologic Time Walk
2/8/2016