earth science

A natural substance made when geological processes occur. It is composed of solid crystals or different minerals.

The gluing together of sediment by new mineral crystals — Cementation can cause sediment grains to stick together, forming sedimentary rock.

The squeezing of sediment by the weight of overlying layers — Compaction can cause sediment grains to stick together, forming sedimentary rock.

Crust that lies beneath a continent — Continental crust is about 25–70 km thick and is less dense than oceanic crust.

The movement of continents around the surface of Earth — Continental drift theory was proposed by Alfred Wegener in 1912 but was widely accepted only in the 1960s.

divergent boundaries

A place where two tectonic plates move towards each other — At convergent boundaries, mountain ranges, ocean trenches and volcanoes can form.

oceanic-oceanic: the plate subducts beneath the other, making a trench, and sinks into the mantle to melt into magma. This magma then rises to the weakened part of the plate to form underwater volcanoes

convergent - oceanic: the oceanic crust which is denser, subducts beneath the continental crust, creating a trench where the oceanic sinks into the mantle to form magma. This magma also makes volcanoes with eruptions.

Cleavage, hardness, lustre, streak, colour

Most crystals are minerals made up of a crystalline structure.

A place where two tectonic plates move away from each other— At divergent boundaries, rift valleys and mid-ocean ridges can form.

Two oceanic plates separate and make a mid-ocean ridge. The plate is also weakened, allowing magma to seep through

Two plates made up of continental crust split and create a rift-valley. The plates are both weakened allowing magma to rise through and form a volcano.

Rift valleys are formed from divergent boundaries and overtime, water rises through to become a mid-ocean ridge. This turns into a basin and magma rises through to make an underwater volcano. While all of this is taking place, it expands the oceanic crust

The theory of plate tectonics states that Earth’s surface is broken up into rigid slabs of rock. These are called tectonic plates. The plates are made up of the crust and the solid upper layer of the mantle. Taken together, these are known as the lithosphere. The lithosphere sits on a layer of the mantle that is partially melted. This semi-liquid layer allows the plates to move horizontally, carrying the continents with them.

The outermost layer of the earth - part of the lithosphere

A place where two tectonic plates slide past each other At transform boundaries, earthquakes often occur as pressure along faults is suddenly released.

The sudden shaking of Earth’s surface — An earthquake is a natural hazard that occurs when two slabs of rock suddenly slip against each other.

The wearing away and removal of rock — Eroded sediment is transported by wind, water or ice.

When rocks are changed in their substances or they are broken down by chemicals

their hardness

weathering that occurs physically and breaks down rocks into small fragments

CO2 + Water = carbonic acid Iron + Oxygen = iron oxide (rust) acid rain