Geologists use a wide variety of methods to understand the Earth's structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, and numerical modelling.In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change.
Geology also plays a role in geotechnical engineering and is a major academic discipline.
The majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth.
By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth.
Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates.
Free 5-day trial Geologic time extends back 4.6 billion years.
Because the earth is so old and rocks formed millions of years ago, geologists needed a way to date rocks and rock units called strata.
So, basically it's the difference between saying 'I'm 25 years old, and my sibling is 20 years old' and 'I'm older than my sibling.' Geologists use a variety of techniques, or principles, to determine the relative age of a rock unit.
Principle of original horizontality: This principle simply states that deposition of rocks occurs horizontally or nearly horizontally. Most deposition occurs as the ocean deposits sediment flat and horizontally on existing rock, either on the ocean floor or on the continent.
Your goal is to study the smooth, parallel layers of rock to learn how the land built up over geologic time.