4.2.2 - Technology for Environmental Change

Question 1

Radiometric dating/geochronology

Answer 1

Dating of fossils, minerals, rocks
By the content of radioactive isotopes
* Dating by rate of decay
E.g. uranium 238, carbon 14

Question 2

Technologies to measure radioactivity in rocks

Question 3

Fission track dating

Answer 3

Form of radiometric dating

Electron microscopes identify tracks left in the rock surface by uranium releasing particles and energy. Density of marks is analysed to estimate an age.

Question 4

Gas analysis

Answer 4

Dating of ice cores

To reconstruct atmospheric concentrations (particularly carbon dioxide and oxygen).

• Ancient carbon dioxide levels are used to infer past climates, which would affect the flora and fauna
• The change of atmosphere composition across time can with the current climate crisis.