geophysical techniques

• Desk studies are office based exercises that involve gathering published and available information. It can identify broad areas where deposits are likely to occur. 
• Geophysical methods fill detail between boreholes to search for anomalies before drilling. 
• Methods:

  • Magnetic survey 
  • Electrical surveys 
  • Electromagnetic 
  • Seismic
• Aerial surveys are initial surveys that are carried out by plane, they cover a large area and provide continuous readings. They can identify the best area for more detailed ground surveys. Useful for dangerous or inaccessible areas. Gravity, magnetic and electromagnetic surveys can be done from the air.