DO NOW QUESTION

The Appalachian Mountains (6,684 feet) formed 480 million years ago and used to be as tall as the Alps (15,780 feet) and the Rocky Mountains (14,440 feet). What do you think caused the Appalachian Mountains height to decrease?

Chapter 4.1: The Rock Cycle

1) What is a rock?

A naturally occurring solid mixture of one or more minerals and organic matter

2) List the 4 processes needed to form sedimentary rock.

Weathering: water, wind, ice, and heat break down rock into sediment (rock and mineral pieces)

Erosion: sediment is moved from its original location

2) List the 4 processes needed to form sedimentary rock.

Deposition: sediment that has been moved comes to rest at a new location

Compaction & Cementation: sediments are pressed and “glued” together by minerals dissolved in water

3) What processes form metamorphic rock?

Heat and Pressure: high temperatures and the weight of overlying layers of rock cause metamorphism

4) What processes form igneous rock?

Melting: Extreme heat melts rock creating magma (molten rock)

Cooling: Magma eventually decreases in temperature and solidifies (hardens) into rock

5) What is uplift?

Movement within the Earth that causes rock inside the Earth to be moved up to the Earth’s surface

6) What is the rock cycle?

A continuous process of new rock forming from old rock material

Rock is changed by geological processes into different types of rock

Rocks can follow various pathways

6) What is the rock cycle?

7) What is composition?

The minerals a rock contains

8) What is texture and how can it vary for each rock type?

Texture: determined by the size, shape, and position of grains that make up a rock

Sedimentary Rock: fine-grained, medium-grained, or coarse-grained, depending on the size of the grains that make up the rock

Sedimentary Textures

ShaleFine-grained

SandstoneMedium-grained

ConglomerateCoarse-grained

8) What is texture and how can it vary for each rock type?

Igneous Rock: fine-grained or coarse-grained, depending on how much time magma has to cool

Metamorphic Rock: fine-grained or coarse-grained, depending on the degree of temperature and pressure the rock is exposed to

Igneous Textures

RhyoliteFine-grained

PegmatiteCoarse-grained

BasaltFine-

grained

GraniteCoarse-grained

Metamorphic Textures

PhylliteFine-grained

MarbleCoarse-grained

SlateFine-grained

GneissCoarse-grained