4.1 Geology Flashcards
(11 cards)
What is glaciation?
During the most recent ice age glaciers were brought to the Pennines. They had 2 effects:
They altered river valleys, making them deeper and widening the, into U- shaped troughs
As they melted, the glaciers left features like Malian Cove with a spectacular waterfall
What is the role of geology?
Geology is used to figure out how old a certain area is based on it rock type. 250 to 350 million years ago the U.K. Was covered by tropical seas. As the fish and coral died their skeletons fell to the ground forming strata. As the layers built up pressure was created which squeezed out the water compacting the skeletons into rock, while in other cases calcium carbonate would crystallise around the fragments, cementing them together and even preserving some fossils intact.
What are some past tectonic processes that affected rocks in the Pennines?
- The plate on which the UK sits shifted, away from the tropics.
- Convection currents beneath the plate uplifted rocks from below the sea- becoming land.
- During uplift, some rocks snapped and moved along faults in a series of earthquakes over thousands of years. Each moment disturbed the strata so that they tilted. Sometimes, the faults form a steep edge where uplift has raised some parts more than others. An example of this is the Giggleswick Scar.
How are igneous rocks formed?
Igneous rocks are formed by the the cooling of lavas and magma. They were once molten, then cooled and crystallised.
How are sedimentary rocks formed?
Sedimentary rocks are formed by sediments eroded and deposited by rivers, the sea or on the sea bed.
How are metamorphic rocks formed?
Metamorphic rocks are sedimentary rocks that were heated and compressed during igneous activity- shale becomes slate and limestone becomes marble.
Name a property of a igneous rock.
Most are resistant to erosion
Name a property of a sedimentary rock.
Some are resistant while others crumble easily.
Name a property of metamorphic rocks?
They are hard and resistant.
What rock types are mainly found in the UK’s Upland?
Metamorphic and igneous rocks.
What rock types are mainly found in the UK’s lowland?
Sedimentary rocks.
