1. An Introduction

2. What does a rock want to be when it grows up?
A ROCK STAR

3. We’ve already learned about something called the
WATER CYCLE
so we know a cycle is a process that
REPEATS

4. There are three types of rocks:
Igneous
Lava
Sedimentary
Metamorphic
Sediments
Magma Pool

5. The Rock Cycle . . . is a group of changes
The ROCK CYCLE is NOT a circular cycle but rather a process by which one rock changes into another which can take billions of years.

6. What do you do to a
baby rock?
ROCK IT!

7. Most of the Earth’s crust is made up of rock
Did you know?
Most of the Earth’s crust is made up of rock
Rocks are made up of one or more minerals and
have been formed by heat or pressure in the earth
95% of the Earth’s crust is igneous rock and
metamorphic rock
Sedimentary rock is less than 5% of the Earth’s crust
but it covers 75% of the Earth’s continental surface

8. Classification Rocks are classified by: 1. How they were formed
2. Composition – what the rock is made up of
3. Textures – sizes, shapes, and positions of grains

11. The ROCK CYCLE M M C H/P Metamorphic W/E H/P Sedimentary Magma C/C W/E
Sediments
W/E
Igneous
M = Melting W/E = Weathering & Erosion
C = Cooling H/P = Heat & Pressure C/C = Compacting & Cementing

13. What is a rock’s favorite cereal?
Cocoa Pebbles

14. Rock that forms from the cooling of magma or lava
Igneous Rock
Rock that forms from the cooling of magma or lava

15. Magma

16. Origins – How rock melts
1. Temperature increases
2. Composition changes = lowers the melting point of the rock
3. Pressure on rock decreases
(pressure released)

18. Composition & Textures
The amount of time it takes for magma or lava to cool determines the texture
Glue or paste your Composition & Texture table in this section of your foldable

20. Formation of Igneous Rocks
Pyroclasts
Extrusive
Intrusive
Porphyry:
partially
crystalline
Fig. 5.3

21. Granite rocks are igneous rocks which were formed by slowly cooling pockets of magma that were trapped beneath the earth's surface. Granite is used for long lasting monuments and for trim and decoration on buildings.
Scoria rocks are igneous rocks which were formed when lava cooled quickly above ground. You can see where little pockets of air had been. Scoria is actually a kind of glass and not a mixture of minerals.
Pumice rocks are igneous rocks which were formed when lava cooled quickly above ground. You can see where little pockets of air had been. This rock is so light, that many pumice rocks will actually float in water. Pumice is actually a kind of glass and not a mixture of minerals.
Obsidian rocks are igneous rocks that form when lava cools quickly above ground. Obsidian is actually glass and not a mixture of minerals.

22. How Igneous Rock Is Formed
Igneous rocks are called fire rocks
and
are formed either underground or
above ground

23. Intrusive Igneous Rock
Split the section labeled ROCK FORMATION into two sections
Intrusive Igneous Rock
Underground – Inside
Magma becomes trapped in small pockets
Magma cools SLOWLY underground - bakes
Usually coarse-grained

24. Extrusive Igneous Rock
Above ground - Outside
Formed when volcanoes erupt
Magma above the earth is called lava
Lava cools QUICKLY above ground and in water
Usually fine-grained

25. Magma is molten rock that is Magma forms “intrusive” igneous rock
deep underground
Magma forms “intrusive” igneous rock

26. Lava forms “extrusive” igneous rock
Basalt is an extrusive igneous rock that is very dark in color.
It is the most common type of rock in the Earth's crust and it makes up most of the ocean floor.
This is an image of
the eruption of
Stromboli volcano

27. Sedimentary Rock Rock that forms when sediments are
compacted and cemented together

28. Origins of Sedimentary Rock
Erosion - bits of earth
washed downstream and
settles to the bottom of the
rivers, lakes, and oceans.
Eroded earth is deposited
on top of each other.
Layers are pressed down and
turn into rock

29. Sandstone rocks are sedimentary rocks made from small grains of the minerals quartz and feldspar. They often form in layers as seen in this picture. They are often used as building stones.
Limestone rocks are sedimentary rocks that are made from the mineral calcite which came from the beds of evaporated seas and lakes and from sea animal shells. This rock is used in concrete and is an excellent building stone for humid regions.
Shale rock is a type of sedimentary rock formed from clay that is compacted together by pressure. They are used to make bricks and other material that is fired in a kiln.

30. Composition Clastic – rock & mineral fragments stick together.
The size & shape influences their name

31. Cathedral Rock in Arizona is made of a clastic rock called sandstone
Cathedral Rock in Arizona is made of a clastic rock called sandstone. . These rocks are more than 250 million years old and are now being weathered and eroded away by the creek.
The rocks that make high ridges are much more resistant to weathering than the surrounding rocks.

32. This stream carries sediment that has weathered from mountains in Alaska

33. Sediment (A) may someday become a clastic rock (B) if compacted and cemented together.

34. 2. Chemical Sedimentary Rock -
Forms when minerals crystallize out of a solution like sea water and becomes rock

35. Conglomerate rocks are sedimentary rocks
Conglomerate rocks are sedimentary rocks. They are made up of large sediments like sand and pebbles. The sediment is so large that pressure alone cannot hold the rock together; it is also cemented together with dissolved minerals.
Gypsum rocks are sedimentary rocks made up of sulfate mineral and formed as the result of evaporating sea water in massive prehistoric basins. It is very soft and is used to make Plaster of Paris, casts, molds, and wallboards.

36. These pebbles were deposited in a stream that once flowed over this area in Indiana, USA thousands of years ago.

37. Ripples in beach sand , such as those in the upper photograph (A) may someday become a rock like the sandstone in the lower photograph (B).
This sandstone was part of a beach over 200 million years ago in the Triassic period.

38. 3. Organic Sedimentary Rock -
Forms from the remains of organisms

39. Coquina

40. Structures Features tell the story of formation
Layers are called strata
Strata differs depending on the kind, size and
color of the sediment
The rate of deposition can affect the thickness of layers
What could affect the rate of deposition (deposits)?
The amount of rain – more = flooding & less = drought
Weathering (wind & water) affects the design of
sedimentary rock

41. Weathering
(wind & water) affects
the
design of
sedimentary rock

42. The pre-existing rock is often referred to as the
Metamorphic Rock
Rock that forms when the texture and composition of pre-existing rock CHANGES due to heat or pressure
The pre-existing rock is often referred to as the
“Parent Rock”

43. Origins of Metamorphic Rock
Rocks that have
“MORPHED”
into another kind of rock
Contact Metamorphism – Rock comes into “contact” with magma and cooks
2. Regional Metamorphism – Enormous pressure builds up in deeply buried rock

45. Schist rocks are metamorphic
Schist rocks are metamorphic. These rocks can be formed from basalt, an igneous rock; shale, a sedimentary rock; or slate, a metamorphic rock. Through tremendous heat and pressure, these rocks were transformed into this new kind of rock.
Gneiss rocks are metamorphic. These rocks may have been granite, which is an igneous rock, but heat and pressure changed it. You can see how the mineral grains in the rock were flattened through tremendous heat and pressure and are arranged in alternating patterns.

46. The more you try to be gneiss, the more you get taken for granite!

47. Composition
Scientist understand the history of the rock based on the minerals present and how they have changed

48. Textures
Metamorphic rock is described by two types of textures: Foliated and Non-foliated
Foliated – minerals are aligned and look like pages in a book (A distinct pattern)
2. Non-Foliated – minerals don’t appear to be in any pattern

49. Start
Apply increasing
heat
&
pressure
Finish

50. Here's a chart of some of the key characteristics that can help you identify the rocks within these three main classes.

51. Crystals: Small, flat surfaces that are shiny or
sparkly, like tiny mirrors.
Fossils: Imprints of leaves, shells, insects, or
other items in the rock.
Gas bubbles:
"Holes," like Swiss cheese, in the rock.
Glassy surface: A shiny and smooth surface, like colored glass.
Ribbon-like layers: Straight or wavy stripes of
different colors in the rock.
Sand or pebbles: Individual stones, pebbles, or
sand grains visible in the rock.

52. Review: There are how many types of rocks? 3
Rocks are put in one of these categories (classified) by three things. What are they?
1. Composition 2. Texture How it formed
Igneous rock is classified by composition - being light or dark but we use what words?
Mafic or Felsic
Igneous rock is classified by texture – coarse-grained or fine-grained but we use words to describe where they formed. What words do we use?
Intrusive or Extrusive

53. Sedimentary rock is classified by composition – how it was formed in one of three ways. What are the three ways?
1. Clastic Chemical Organic
Metamorphic rock is classified by composition – What minerals are present and by texture – but we describe the texture based on the presence of a pattern or a lack of a pattern. What words do we use to describe the pattern or lack of a pattern?
Foliated or Non-foliated

54. Igneous rock forms how?
From the cooling and solidification of lava or magma
Sedimentary rock forms how?
From the erosion and weathering of rock
What type of rock can become sedimentary rock?
All types
Metamorphic rock forms how?
From intense heat & pressure changing pre-existing rock

55. The ROCK CYCLE M M C H/P Metamorphic W/E H/P Sedimentary Magma C/C W/E
Sediments
W/E
Igneous
M = Melting W/E = Weathering & Erosion
C = Cooling H/P = Heat & Pressure C/C = Compacting & Cementing

56. The END!