Presentation on theme: "What makes up Earth’s Crust"— Presentation transcript:
1 What makes up Earth’s Crust RocksRocks!What makes up Earth’s Crust
2 Three types of rocks…SedimentaryIgneousMetamorphic
3 What is a rock?A rock is a solid that forms in nature. It may have one or more types of minerals within it (or no minerals at all).
4 Some rocks have minerals, some don’t… Minerals are clearly visible in some igneous rocks like…..There are no mineral crystals in obsidian.Diorite
5 What is the rock cycle? Natural processes that… Rock is reformed FormsChangesBreaks down rocksRock isreformedinto anothertype of rock.
6 The rock cycle in action… shows thethree types ofrocks.IgneousMetamorphicSedimentary Listen and watch how the processes formed the three types of rocks.
7 Igneous Rock Forms when molten rock cools and becomes a solid. Igneous rocks may form inside Earth or on Earth’s surface.Intrusive-forms when magma cools within the Earth.Extrusive-forms when lava cools on the surface.
8 What is a rock’s texture? Texture refers to the size of the mineral crystals: coarse, fine, glassyCoarsePumiceGlassyFine
9 Textures of Intrusive Igneous Rock Intrusive RocksThe size of mineral crystals depends on how quickly the magma or lava cooled.The high temperatures of the interior of the Earth causes magma to cool slowly.Slow cooling allows large crystals to form.
10 How are we able to see intrusive rocks? Ship Rock formed 30 million years ago.Magma cooled to form intrusive rock.Intrusive igneous rockhas been left as weaker rock (like sedimentary) has worn awaydue to weathering & erosion.
11 Textures of Extrusive Igneous Rock The surface of Earth is much cooler than the interior, causing lava to cool quickly.There is no time for large mineral crystals to form.
12 Composition of Igneous Rocks… Most igneous rocks are made up of silicate materialsThe color tells you how much silica the rock has.High levels of silica will be lighter in color.Low levels of silica will be darker in color.
13 What type of rock was carved to create Mount Rushmore? Igneous!
15 Which is formed from cooling magma? Which of these is a rock?A. halite B. granite C. mica D. quartzAnswer: B. graniteWhich is formed from cooling magma?A. metamorphic B. igneousC. sedimentary D. sandstoneAnswer: B. igneous
16 Sedimentary Rocks: “something that settles” Small pieces of rock turn into pebbles, gravel, sand, clay, and plant & animal matter. They tumble down rivers and streams.These pieces settle in a new place and begin to pile up and the sediments form flat layers.
17 Sediments harden into rock in two ways. Compaction- layer after layer of sediments are deposited, they are pressed together tightly to form rock. Cementation- sediments are held together by minerals that have crystallized between them (acting as cement).
18 Sedimentary rocks may be rich in…. Fossils- Remains or trace of an organism from long ago.Coal-Made up of the remains of dead plants. The coal we use today formed millions of years ago in swamps.Limestone-made of carbonate minerals (calcite) from seashells that settle on the bottom of the ocean.
19 COAL: Natures rock…..Coal is made from dead plants and over time pressed into the Earth.
20 Sedimentary Rock tells a story about Earth’s past… These rocks are laid down in layers with the oldest on the bottom.Do you remember what rock layers are called?Law of Superposition or stratification!
21 Do you remember?What layer of rock is the… Oldest?YoungestOldest
22 Metamorphic Rock= Changed Rock SedimentaryMetamorphic
23 Composition and Texture: a way to identify metamorphic rock When mineral grains line up in parallel layers, the metamorphic rock is said to have a Foliated texture.SlateGneiss
24 Non Foliated Metamorphic Rock When a metamorphic rock does not have “foliation” it typically has only one mineral, therefore no parallel banding patterns.Typically made up of one type of mineral so different minerals can not line up in bands.Marble formed from limestoneQuartzite forms from Sandstone
25 Metamorphic Rocks are formed when… ++=Metamorphic Rock
26 How much of Earth’s Crust is made of each type of rock? Surface = 75% Sedimentary Rock Entire Crust = 95% Igneous and Metamorphic Rock
27 What type of rock is the most common on the surface of Earth’s crust? A. metamorphic B. igneousC. sedimentary D. sandstoneAnswer: C. sedimentary95% of Earth’s entire crust consist of what type(s) of rock?A. metamorphic B. sedimentary C. igneous D. igneous and metamorphicAnswer: D igneous and metamorphic