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Flashcards in Geologic Deck (40):
1

In ____, who proposed the idea of continental drift?

Alfred Wegener, a german scientist, in 1912

2

Why did the other scientists reject/accept Alfred's ideas at the time?

Alfred could not provide credible mechanism for the process of continental drift

3

When was Pangaea formed?

250 million years ago

4

What were Alfred's 4 pieces of evidence?

- Jigsaw fit
- Glaciation
- Fossils
- Mountain chains

5

How is glaciation support the evidence of continental drift?

South America, South Africa, India, and Australia indicate they experienced glaciation at about the same time (glacial striations are left when boulders are dragged beneath glaciers; scratch surface, creating grooves). In their current positions, the striation point to continental glaciers originating in different locations. However, by aligning the continents, the striations point to 1 continental glacier at the pole

6

What is the Earth's thickest layer?

Mantle

7

What is the Earth's thinnest layer?

Crust

8

What elements are in the crust?

Granite + basalt

9

What elements are in the core?

Nickel + iron

10

Which layer of the Earth is liquid?

Outer layer

11

What is the lithosphere?

Crust + upper mantle, divided into tectonic plates that are solid

12

What is the asthenosphere?

Tectonic plates float on this hot, semi-liquid upper mantle, beneath lithosphere

13

What are the convection currents in the Earth caused by?

Hot material of lower mantle rising, cooling dropping, heating, etc.

14

When was the Precambrian era? What organisms were there?

4600 - 570 million years ago

Fossils + bacteria

15

When was the Paleozoic era? What organisms were there?

50 - 245 million years ago

Reptiles, fish, shells, amphilbians

16

When was the Mesozoic era? What organisms were there?

245 - 66 million years ago

Dinosaurs, ammonites

17

When was the Cenozoic era? What organisms were there?

66 - 0 million years ago

Neanderthals, mammals

18

What can happen at convergent boundaries?

Subduction zones = volcanoes, tsunamis, earthquakes
Collision zones = mountains

19

What can happen at divergent boundaries?

Seafloor spreading = mid-ocean ridge, new ocean floor

Rifts = New sea/ocean, new tectonic plate

20

What can happen at transform boundaries?

Strike-slip fault = Earthquakes

21

What are volcanoes?

Openings to Earth's core

22

What is pyroclastic flow?

Dense mass of hot ash, lava, gas from volcano @ high speeds

23

What is lahar?

Flows of hot ash and mud

24

What is a volcano bomb?

Large rocks hurled out as far as 5 miles from crator

25

What is lava?

Magma at the surface

26

What are the pros + cons of volcanoes?

- Soil
- Geothermal energy (heat from Earth)

- Seismic activity that could damage stuff
- DANGER!

27

What are hot springs?

Remains of ancient active volcanoes

28

What are the 3 types of volcanoes?

Cinder cone, composite, shield

29

What type of volcano is Mexico's Paracutin?

Cinder cone

30

What type of volcano is Mt St. Helen's?

Composite

31

What type of volcano is Hawaii's Kilauea?

Shield

32

What type of volcano is Italy's Mt Vesuvius?

Composite

33

What type of volcano is Mt. Stromboli?

Composite

34

What are 3 examples of igneous rock?

Granite, basalt, obsidian

35

Igneous rock have ________ and _______

Gas bubbles + glassy surface

36

What are 3 examples of sedimentary rock?

Shale, limestone, conglomerate

37

What are 3 examples of metamorphic rock?

Granite = GNEISS
Shale = SLATE
Limestone = MARBLE

38

Sedimentary rock have ________ and _______ and ________

Sand + pebbles + fossils

39

Metamorphic rock have _________ and ________

Crystals + ribbon-like layers

40

What are the 5 processes of the rock cycle?

Heat and pressure
Melting
Cooling
Weathering & erosion
Compacting & cementing