Power washing is used to clean off any dirt that could be on the rock or outcrop so that the geologist can observe and document the geology. A jet of water from a pressure pump is used to loosen and remove most clays or dirt. This is especially important in areas like Northern Ontario where the rocks are often covered in a thick layer of clay.
Once the rocks have been cleaned, it will make it easier for the geologist to see what types of soil and rocks they will be dealing with. The geologists will also be able to take better rock samples without any sand or gravel interfering with the sample. This is important because it allows for more accurate documentation of the geology in an area. power washing is thus an essential tool for any geologist working in Canada, especially in regions like Northern Ontario where the outcrops are often covered in a thick glacial till.