Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the field and the laboratory.

In his paper, he explained his theory that the Earth must be much older than had previously been supposed to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea, which in turn were raised up to become dry land.

[7] Some geologists also work for a wide range of government agencies, private firms, and non-profit and academic institutions.

They are usually hired on a contract basis or hold permanent positions within private firms or official agencies (such as the Geological Survey and Mineral Exploration of Iran).

[citation needed] Local, state, and national governments hire geologists to work on geological projects that are of interest to the public community.

The investigation of a country's natural resources is often a key role when working for government institutions; the work of the geologist in this field can be made publicly available to help the community make more informed decisions related to the exploitation of resources, management of the environment and the safety of critical infrastructure - all of which is expected to bring greater wellbeing to the country.

[citation needed] Geologists in academia usually hold an advanced degree in a specialized area within their geological discipline and are employed by universities.

[9] The rules and guidelines codified in National Instrument 43-101 were introduced after a scandal in 1997 where Bre-X geologists salted drill core samples at a gold exploration property in Busang, Indonesia.

The falsified drilling results misled Bre-X investors and upon discovery of the fraud, the company collapsed in the largest gold mining scam in history.