There are 3 types of rock: Sedimentary Metamorphic Igneous Types of Rock
Small particles of rock formed by weathering are transported into the sea where they are deposited (sink) and form a sediment. At this stage dead creatures may become trapped within the sediment giving rise to fossils. Fast flowing water sedimentation Slow water Pressure cementation Sedimentary Rock – Deposition Over millions of years, the pressure of the layers formed above and the effects of salts cement the sediment together to give sedimentary rocks like sandstone and mudstone.
Sedimentation + effects of pressure and minerals. Sedimentary Rock – Sedimentation Layers of sediments getting older
Some sedimentary rock is formed in a different way. Certain minerals are dissolved in seas and lakes. Over millions of years these seas or lakes have dried up. As the water disappeared the dissolved minerals precipitated. Chalk and limestone, common in the UK, are often formed in this way. Dissolved minerals evaporation Precipitation Pressure Sedimentary Rock - Evaporation
Sedimentary rocks consist of lots of small particles and may be soft and crumbly They do not normally contain crystals but may have fossils trapped within them. When viewing a whole cliff face of sedimentary rock it is often possible to see layers where slightly different sediments have been deposited. Sedimentary Rock - appearance Sedimentary rocks consist of lots of small particles.
Sedimentary Rocks sandstone sandstone chalk limestone
sandstone orangey coloured rock looks like lots of sand grains stuck together quite soft
limestone grey/white coloured rock mostly made from crushed sea-shells may contain fossilised shells
chalk grey/white coloured rock. mostly made from crushed sea-shells may contain fossilised shells
Metamorphic rocks are formed by the effect of extreme pressures and temperatures deep within the Earth. This alters the structure of the existing rock. Metamorphic Rock - formation
They are usually denser and harder than sedimentary rocks. They often have layer structures of crystals caused by the effect of heat and pressure. They sometimes show distortions caused by the movements that led to their formation. This may give rise to wavy or zig-zag patterns within the rock. Regular layers of crystals that sometimes also have a wavy or zig-zag arrangement Metamorphic Rock - properties
Metamorphic Rocks marble slate Enlargements on next two slides
marble High temperatures cause the shells in limestone to break down into crystals giving a harder smoother rock.
slate Pressure and some heat makes the particles in mudstone line up in one direction. This makes a rock that can be split into sheets.
Deep within the ground is molten rock called magma. Sometimes this bursts through the surface in the form of volcanoes. extrusive igneous rock intrusive igneous rock magma Igneous Rocks - Formation • Igneous rocks are formed when molten magma cools and solidifies. • This may happen within the ground, or in the case of volcano lava, above ground.
The appearance of igneous rocks is affected by how fast they cool. Igneous Rocks – Rate of Solidification Rocks formed within the ground are known as intrusive igneous rocks . They cool slowly and this gives time for large crystals to grow. Rocks formed once the magma has burst through the surface are called extrusive igneous. They cool quickly. As a result crystals are much smaller.
Igneous Rocks - intrusive granite A hard grey rock consisting of randomly arranged crystals.
Igneous Rocks - extrusive pumice Extrusive igneous rocks, like pumice and basalt, do not have large crystals and tend to be less dense than intrusive rocks like granite.
Igneous Rocks - extrusive basalt - pillars
Igneous rocks are hard. They contain crystals. The the size of the crystals depends on how quickly the rock solidified. The crystals are disordered (unlike some metamorphic rocks.) They never contain fossils. Igneous rocks consist of a disorderly collection of crystals Igneous Rocks – Properties
Am I igneous, sedimentary or metamorphic? Description I am formed by heat and pressure. I contain some really big crystals. I am mudstone. I contain many small grains “cemented” together. My particles are arranged in bands that are easily split apart. I am pumice. I contain many fossils. Type metamorphic igneous (intr) sedimentary sedimentary metamorphic igneous (ext) sedimentary
Rock Formation rocks are broken up by the action of weather transportation and deposition rocks rise to surface by uplift and erosion volcano Igneous rocks basalt sea Sedimentary rocks mudstone Igneous rocks granites rises to surface where it cools rapidly high pressure and temperature slow solidification Metamorphic rocks slate and marble melt magma
Rocks take part in a rock cycle. Molten ___________ solidifies at or near the surface of the Earth to form ___________ rocks. These undergo ___________ where they are broken up by ___________ and chemical processes. Fill in the gaps in the sentences. magma weathering sedimentary physical igneous metamorphic magma igneous weathering physical
The fragments of rock are carried to the ___________ by rivers. Here they sink and form ___________ rocks. Over millions of years heat, ___________ and movement may change these sedimentary rocks into ___________ rocks. Some of these will sink deep into the Earth and turn into ___________ and the cycle is repeated. Fill in the gaps in the sentences. magma pressure sedimentary sea igneous metamorphic sea sedimentary pressure metamorphic magma
What type of rocks do these diagram represent? igneous metamorphic sedimentary
A Intrusive Igneous B Extrusive Igneous C Metamorphic D Sedimentary 1. What type of rock is granite?
A Intrusive Igneous B Extrusive Igneous C Metamorphic D Sedimentary 2. What type of rock is slate?
A Intrusive Igneous B Extrusive Igneous C Metamorphic D Sedimentary 3. What type of rock is limestone?
A Intrusive Igneous B Extrusive Igneous C Metamorphic D Sedimentary 4. What type of rocks are pumice and basalt?
A Intrusive Igneous B Extrusive Igneous C Metamorphic D Sedimentary 5. What type of rock is mudstone?
A Pumice B Limestone C Slate D Granite 6. What type of rocks is made from mudstone or shale?
A 1 B 2 7. In this diagram showing a cross section of a volcano, where would granite form? 1 2