Key Words: GEOLOGY UNIT 1.3

Continental drift - the large-scale horizontal movement of continents during geological time

Tillites - ancient glacial deposits preserved within a rock sequence

Evaporites - minerals formed by the exaporation of saline water

Mid-ocean ridges - large mountain chains running down the centre of oceans

Magnetometer - towed behind a ship to measure changes in magnetism. Can detect the strength and direction of the magnetic field

Gravimeter - towed behind a ship to measure changes in gravity

Mafic - describes igneous rocks with 45 to 52% silica e.g. basalt

Pelagic - applied to organisms living in, and sediment deposited from, the main body of sea water

Planktonic - applied to organisms that float in sea water

Clastics - made up of fragments of pre-existing rock

Continents - situated on crust with an average thickness of 35km and a mean composition…