how can you deduce different geological stractures from the magnetic map and when in field?

Question

especially fault, shear zones, fold,foliation. help mi im confused!!!

Answer 1

The only time a magnetic map will be helpful in field work is when there are magnetic anomalies in the rocks beneath the surface. Very few minerals have magnetic properties, and of them only magnetite has strong magnetic properties. Magnetite is commonly found in mafic rocks, such as basalt. Providing you have a layer of basalt as you survey an area the magnetics would suddenly change when crossing a normal or reverse fault, but might not change when crossing a transverse fault. A shear zone might have erratic readings. An anticlinal fold might gradually increase, reach a maximum and then gradually decrease, while the opposite would occur for a synclinal fold. I can't see how foliation would show up on a magnetic map, since it is associated with metamorphic rocks and is seen in the hand sample, not on a field scale.