Lecture 7

Question 1

How do metamorphic rocks form?

Answer 1

Form by alteration of other rocks at temperatures and pressures greater than at the Earth’s surface.

• Rocks change chemical composition without melting
• Form from a parent rock, which could be igneous, sedimentary, or metamorphic in origin.

Question 2

What does the degree of change in a rock depend on?

Answer 2

On the type and intensity of metamorphic processes involved:

• heat
• pressure
• chemical fluids

Question 3

What is regional metamorphism?

Answer 3

• responsible for most metamorphic rocks, and is the result of mountain building at convergent boundaries

Question 4

What is grade?

Answer 4

legal of temperature and pressure of metamorphism

Question 5

What is foliation?

Answer 5

alignment of platy minerals caused by applied pressures

Question 6

True or False: With increased temperature and pressure, there will be increasing metamorphic grade and foliation.

Answer 6

True

Question 7

When does foliation only occur?

Answer 7

Foliation only occurs when specific platy minerals make up the rocks composition.

Question 8

What is marble made out of?

Answer 8

• calcite and/or dolomite

Question 9

What is limestone parent?

Answer 9

marble

Question 10

What is quartzite made of?

Answer 10

• nearly pure quartz

Question 11

What is quartzite the parent of?

Answer 11

sandstone

Question 12

What is contact metamorphism?

Answer 12

Igneous intrusion “bakes” surrounding rocks

Question 13

What is hydrothermal metamorphism?

Answer 13

Results from percolation of hot watery fluids.

Question 14

What is burial metamorphism?

Answer 14

Similar to regional metamorphism

Question 15

What are sedimentary rocks formed out of?

Answer 15

sediment (bits of previously existing rock/organic matter)

Question 16

How do sedimentary rocks form?

Answer 16

by deposition

Question 17

Why do sedimentary rocks crete horizontal beds called strata?

Answer 17

because they form by deposition

Question 18

What are the major divisions of sedimentary rocks?

Answer 18

• siliciclastic/detrital
• biological
• chemical

Question 19

What are sediments produced by

Answer 19

• weathering, erosion of other rocks
• crystals precipitated from seawater
• skeletal debris of organisms

Question 20

What are siliciclastic/detrital rocks?

Answer 20

• sedimentary rocks composed of class of silicate minerals cemented together with minerals from groundwater after they re buried.

Question 21

What is the basic siliciclastic cycle?

Answer 21

• uplift, causing erosion
• transport through wind and/or water to a centre of deposition
• burial resulting in lithification (often due to cementation via dissolved minerals in groundwater)