8.1 Flashcards
(22 cards)
Name 3 different types of rock
Igneous, metamorphic , sedimentary
What are the five steps of sedimentary rock formation
1 weathering : breaking up of rocks into smaller pieces
2 erosion: movement or transportation of pieces of rock
3 deposition: pieces of rock rest on surface
4 compaction: compressing rocks together
5 lithification: dissolved minerals crystalline and cement rocks together
Sedimentary rocks make up 3/4 of all rocks on earth what do they contain and what are they made up of
They contain fossils and made up of clasts (pieces of other rock s)
Characteristics of sedimentary rock and example
Clastic, chemical may contain crystal very hard, organic layers of different sediment
Eg limestone, coal
How Are metamorphic rocks formed
Under earth surface fro metamorphis that occurs due to intense heat and pressure
Characteristics of metamorphic rocks
Ribbon like layer, shiny crystals, harder than sedimentary rocks, precious gems eg sapphire and ruby
Used for flooring, jewellery
What are fossils
Evidence of plants and animals that once lived, the remains have been preserved in rock
Types of fossils
Mold and cast : physical characteristic impressed into rock, usually hard part of organism teeth skeleton
Trace: imprint left and found in soft segments eg tracks
Amber: trapped In tree resin and wholly preserved in a suspended state
What is igneous rocks
Rocks that cool quickly while underground eh molten or magma
What is the rock cycle
Is a cycle geologist use to explain the cycle of change rocks undergo from one form to the other. There are four processes, 1 heat and pressure, 2 melting and cooling, 3 weathering and erosion, 4 compacting and cementing
What causes changes in our landscape
Weathering, erosion, deposition
What is weathering
The process of physical and chemical weathering (breaking down ) of rocks. Weathering can occur from temperature change, action of water and ice, crystallisation of salts. Wind and living plants
Chemical weathering
Involves chemicals in water and air reacting with rock and changing it. Gases, water and acid
Erosion
Weathering breaks up surface of rock, erosion wears away and removes loosened material, eg of erosions are rivers ice sea wind
What is sedimentation
The process of depositing eroded rock particles
What are the key characteristics of soils?
Texture - determined by the size of the particle that make up the soil.
Structure - refers to how well the soil particles join up to form clumps
Water Holding Capacity - measure of how much water a particular amount of soil can hold
Permeability- measure of how fast water enters the soil
Consistency - the tendency of soil particles to stick together
List the agents of erosion?
Water, wind and ice
Explain how temperature change and water can split a rock?
Ice can split rocks by cooling them rapidly. Ice also widens cracks in rocks
What are sedimentary rocks
Rocks made from sediments
Name the 3 main types of sedimentary rocks
Clastic - have layers, may contain fossils
Chemical sediments - soft and most contain crystals
Organic sediments - can be layered, usually soft
What are metamorphic rocks
Rock that has changed form. Happens when high temperature and pressure alter igneous and sedimentary rocks
Name the Model geologists use to explain the changes in rock from one type to another.
The rock cycle. Try and draw
