Working “out in the field” is an incredibly exciting activity, but how do archaeologists and paleontologists know where to dig?
How do archaeologists know where to dig?
Archaeologists use an array of different sources and techniques to determine locations for archaeological excavations. Here are some of the key ways archaeologists identify potential dig sites so they can choose where to dig and excavate:
Historical research: Archaeologists study historical documents, maps, and records to identify areas of past human activity or settlements when choosing to explore new locations to excavate.
Surface surveys: By walking across landscapes that are in archaeologically rich areas, researchers conduct visual surveys to look for artifacts, structures, or other signs of past human presence visible on the ground surface.
Test pits or shovel tests: A tried and true method archaeologists use is to dig small exploratory holes to sample subsurface deposits. If anything is found, then further excavation will be undertaken.
Geophysical surveys: Archaeologists have found that new technologies like ground-penetrating radar, magnetometry, and electrical resistivity help to detect subsurface structures. These technologies are becoming more widely used since they don’t require unnecessary digging unnecessary test pits and shovel tests.
Aerial and satellite imagery: Researchers analyze aerial photographs and satellite images to spot unusual patterns or features in the landscape that may indicate buried structures or sites.
Local knowledge and oral histories: Consulting with local communities and indigenous groups is incredibly important to gather knowledge about sites that have been spoken about over time.
Previous archaeological work and layered sites: Given that many civilizations were literally built on top of and close to one other, archaeologists revisit locations in and around past excavations. An example is Maree Project in Ireland, which was excavated in the 1940s and is now excavated again. Rathgurreen Ring Fort was in use from 4th to 12th century AD. However, archaeologists are newly working the site in the belief that it may have been in use since the Stone Age (8000-4000 BC).
Accidental discoveries: One of the most prolific sources of dig locations is through accidental discoveries by construction workers, farmers, or members of the public. England has so many accidental discoveries, that the country instituted Ancient Monuments legislation that compensates landowners for archaeological discoveries made on their land. This encourages citizens to share their discoveries with researchers and museums.
How do paleontologists know where to dig?
To find fossils, paleontologists primarily rely on geology to know where to dig for dinosaurs and other fossils. Paleontologists use five key ways to know where fossils are. These include:
Geological Surveys: Fossils are found in sedimentary rock layers, which are formed from the accumulation of sediments over time. Paleontologists know which layers are fossil-bearing and they also know which formations are fossil-rich. They often begin their search by studying geological maps and formations to target locations that are likely to contain fossils, such as the Two Medicine Formation in Montana.
Surface Surveys: Areas lacking in much vegetation such as the badlands “weather away” regularly, exposing fossils. Paleontologists conduct surface surveys to look for fossils that have been newly exposed. This method involves walking over areas and visually inspecting it for any signs of fossils.
Understanding Erosion and Natural Exposures: Natural processes such as erosion can expose fossil-rich layers that were previously buried. Paleontologists often study areas where erosion has occurred, such as riverbanks, cliffs, beaches or roadcuts, to find fossils.
Previous Discoveries: Paleontologists also rely on previous discoveries in an area to guide their searches. If a particular region has yielded significant fossil finds in the past, it is likely to have more fossils waiting to be discovered. This knowledge helps refine search areas and increases the chances of finding new specimens.
Accidental discoveries: Many fossils have been found by sheer luck! Amateur or vocational fossil hunters and rockhounds literally stumble upon finds that have contributed to the knowledge of paleontology around the world. A recent, well-known accidental find was uncovered by a mining company in Alberta, Canada. What turned out to be a new species of ankylosaur, called Borealopelta markmitchelli was one of the most well-preserved dinosaurs ever found.