Geophysical exploration for metals

Question 1

Gravity surveys

Answer 1

Positive gravity survey

High density mafic intrusion which may contain cumulate ore deposits from magmatic differentiation and gravity settling

Presence of dense metallic ore minerals

Negative gravity anomali

Low density silicic intrusion, which may have hydrothermal mineral veins around it

Question 2

Magnetic surveys

Answer 2

Magnometer

Minerals rich in iron minerals provide positive magnetic anomalies

Mafic intrusion which contain cumulate ore deposits

Presence of the mineral magnetite

Question 3

Electromagnetic surveys

Answer 3

Metal sulfides eg chalcopyrite

Question 4

Electrical resistivity survey

Answer 4

Good conductors will have low resistance and metals are good conductors