Non Invasive Archaeological Methods
Archaeological Techniques: Non-Invasive and Survey
1. Magnetometry with a magnetometer
The process of magnetometry identifies the changes which occur in the magnetic properties of the soil. The magnetic properties of the soil can be effected by the burning of materials like brick, and the filling of differing soils over time.
2. Electrical resistance tomography
A process which takes a great deal of time, however electrical resistance tomography (ERT) can provide details about changes in straitgraphy and geology at great depths and across large plains.
Resistivity works by implementing a machine which passes an electrical current inbetween two probes. These probes measure the amount of time it takes for a current to travel between mobile vs static probes. A quickly passing current identifies a ditch while a slow moving current identifies a wall or track.
4. Ground Penetrating Radar
This method is used to see what is underneath the ground. A radar beam is sent through the ground and a measurment is taken calculating how long it takes the radar beam to bounce back. A three-dimensional image of objects under the soil is created up to a depth of about 10 meters. This process is not widely used because it is costly and the processing of data is complicated.
5. Geochemical survey
Soil samples are taken from the top level of soil using a coring device. After the samples are gathered, they are sent to a lab where they are turned into pellets. These pellets are ran through an EDX-RF device which anyalyzis the core samples element composition. the amount of elements in each core sample gives insight to what type of occurences took place in the location the sample was gathered. Areas of high phosphate levels allude to an area where livestock were kept. Areas of high calcium content suggest burial grounds or sedimentary rock deposits.
6. Light Detection and Ranging (LiDAR)
LiDAR (Light Detection and Ranging) remotely gathers 3-
dimensional point cloud data of the Earth’s surface. This technology is fast, relatively cheap and can map vast areas in a quick manner, even in areas covered in dense vegetation.