4.1 Geology UK Flashcards
Definition, approximate age, 3 example and location in the UK of igneous rocks.
Created by by volcanic activity when magma or lava cools and forms rocks made of crystals that are hard. It is resistant to erosion and are the worlds oldest rocks aged 350 million years old. It is found in the north west of the UK and are granite, basalt and obsidian
Definition, approximate age, examples and location of sedimentary rock
Sedimentary rocks are formed when layers of sediment, such as tiny shells and skeletons, are compacted together. There are chalk, clay and shales. It is in the south of the UK and is around 200 million years old
Compare metamorphic and igneous rocks
Metamorphic rocks are changed by heat and pressure of other rocks like igneous rocks but igneous rocks are formed by molten rock. Metamorphic rocks are more harder and compact.
Compare the formation and characteristics of granite and carboniferous limestone.
Granite is formed from magma cooling deep underground and contains crystals of quartz and is very resistant. Granite has lots of joints and wear down fast. Carboniferous limestone had rainwater slowly eating away at limestone through joints and creates caverns and gorges.
Compare the formation and characteristics of chalk and slate
Slate forms in layers which create weak planes in the rock and is resistant to weathering. They are often forming rugged upland landscapes, these are impermeable. Chalk forms in escarpments in uk lowlands and at the coast, chalk is impermeable and water can flow through it.
Explain when and how active volcanoes shaped the uplands of the uk
520 million years ago active volcanoes forced magma through the earths crust and cooled to form igneous rocks which are now in the the upland of the UK.
Explain how glacial erosion and deposition shaped the uk uplands
The ice in the upland eroded the landscape due to how powerful the ice was and made u-shaped valleys. The glaciers deposited lots of materials when they melted mostly in the east. Clay and sand was deposited by the glaciers.
Explain when and how sedimentary rocks was formed in the uk lowlands
200 million years ago the uk was under a tropical sea, dead marine organisms where compressed together. The rock then came up due to tectonic movement in the lowland.
Explain how glacial deposition shaped the uk lowlands
Glaciers from the north west picked up sediment they eroded. The glacier carried the sediment south and melted leaving deposition.
Explain how scarp and vale topography forms in the UK lowlands.
An anticline was pushed up due to tectonic processes, the glaciers meltwater cut a u-shape right through it and exposed the chalk. This created an weald with escarpments in the steep areas in the north and south downs. It has a sequence of scarps and dip slopes and valleys which are the vale.
