Sedimentary Rocks: Sedimentary rock is formed from sediments that have settled at the bottom of a lake, sea or ocean and have been compresed over a long peirod of time (usually a few million years). The sediment comes from eroded rocks carried there by river or ice and also the skeletons of sea creatures. Sedimentary rock is very smooth!
Examples include sandstone and chalk.
Metamorphic Rock: Metamorphic Rocks are those that have been subjected to a great heat and/or pressure, causing them to change into another type of rock. They are usually resistant to weathering and erosion and therefore are very durable. The most common types of metamorphic rocks include Slate and Schists.
vIgneous Rock: Igneous rock is fromed by, when the Earth is hot, it is often hot enough to melt rocks. The Molton Rock is called Magma, which then when the Magma Cools and Solidifies, a type of rock called Igneous Rock Forms. Igneous rock contains randomly interlocking Crystals. The size of the Crystal depends on how quickly the molten magma solidifies. The more slowly the Magma cools, the bigger the crystals.
Examples Include Basalt and Granite.
Rocks in the UK
We have sedimentary rock in the UK, as in the past their were large areas of the UK, that were covered by warm tropical seas. Marine deposits from these seas has caused the creation of chalk along the coast.
We have igneous rock in the UK, as in the past their was volcanic activity in the UK, meaning the Uk was on the edge of a tectonic plate boundary, at some point in history.
Basalt is found in the UK and cools on the surface.
Granite is also found in the UK, and cools on the earth's crust.
rock in the
we have the
Formation of Sedimentary Rock
1: Eroded sediments end up in the water and begin to settle. (Sedimentation)
2: With time more layers pile up and press down lower layers. (Compaction)
3: More layers and further compaction forces out water from the layers.
4: Salt crystals
glue the layers
The rock mass
Tors: Tors are a rock outcrop formed by weathering, usually found near the summit of a hill.
Weathering: Weathering is caused by conditions asscosiated with the atmosphere, such as temperature and rainfall. Weathering breaks down rocks into smaller and smalle pieces. Rock is broken down "in situ" which means the broken bits of rock aren't taken away.
Phyiscal (Chemical) Weathering is when the rock is broken down into smaller peices. The chemical compositon of the rock isn't changed.
Freeze Thaw Weathering: 1: Freezing and Thawning of the rock has caused a small gap to be created in the rock (Timescale 100 years +) 2: The gap is filled with rain water and speeds up the Freeze Thawning process, causing a bigger crack to open. 3:This eventually causes a crack that splits the rock into 2 small peices of rock.
Diurnal Temperature Range: The difference between the highest and lowest temperature in a area.