Geochemistry

Carbon 14 has a half-life of 5,730 years, and therefore it can be used to date very accurately a large majority of things, particularly wood and so on.

It is only not useful for ancient things where all the carbon 14 will have gone, or almost gone – and for these there are other isotopes of other elements, that can be used with a much longer half-life.

Sedimentary rocks have a clue to their origin in the name – sediment.

They are the products of lots and many dead marine creatures, which piled up on the sea floor as they were formed in water. These piled up together over a period and the pressure of them all caused the formation of rock.

Magma is part of the layer just under the crust.

It reminds us that whilst everything seems solid underfoot actually that is not quite so, and there are only relatively thin layers on top that move and float on a sea of magma underneath, it is this that moves the continents around the surface of the planet, all be it very slowly indeed.

Granite is a hard, igneous rock. It is made up of mica, quartz, feldspar and sometimes bits of other rocks as well. Granite is usually pink, white, or grey. It is crystalline and so shines.

One in academia for instance will spend the day doing research and writing papers and lecturing.

Others will be involved in practical work in the field, examining rocks and structures and making deductions about age and formation and so on.