Geologists work with the earth as it is now to understand how it was in the past and how it might be in the future. Certain tools and instruments make a geologist's job easier to complete. Some of these tools are very simple and haven't changed much over decades, while others are more high-tech, specialized and expensive.
The Brunton compass is a specific type of magnetic compass created by geologist David W. Brunton in the 1890s. With this compass, a geologist can measure "strike and dip" -- the physical orientation of rock layers, faults and other geographical features. By knowing the exact measurements of sediment layers, the geologist can make more accurate guesses as to when, why and how the earth was disrupted. The Brunton compass has been a fixture of geological surveying since its invention, though nowadays it may be accompanied by all-purpose GPS devices and computer or smart phone applications that help calculate strike and dip.
A hand lens, also known as a magnifying glass, is used to give a geologist a magnified view of the earth or rocks she’s examining. Sediment, fine-grained earth, soil and rocks often have much more detail than the human eye can see without magnification. Many geologists use small foldable hand lenses that can be worn on a cord around the neck so that they are always at the ready.
Hammers & Chisels
Geologists use a series of small hammers and chisels for breaking rocks. The outer surface of a rock is rougher and more eroded than the protected inside. To uncover the history and composition of a rock, a geologist will split it in half to reveal the inside layers. The color, texture and patterns of the inside of a rock can help a geologist discern things about the immediate environment. A geologist can also determine what the rock is made of based on how easily it splits, and the way it splits, chips or breaks.
Rock hammers come with pointed tips, best for igneous or metamorphic rocks, or chisel tips, best for sedimentary rocks and soils. Chisels, paired with small sledge hammers called crack hammers, are additional precision tools for working with minerals and fossils.
A geologist working outside requires a durable field book, both for quick reference and for taking field notes. Charts, tables, shorthand notes about rocks, soil and minerals, and blank paper for taking new notes are included in a field book. Field books are often water- and weather-proof to withstand harsh conditions. Detailed field books include a scale against which to compare rock, mineral, soil and fine-grain samples. Waterproof pens and topographical maps are also key accessories included in a geologist's daypack.