What type of mechanical weathering occurs slowly over time and only in certain geographical locations?

Frost Action in temperate regions of the world

Salt weathering in coastal and arid regions

Thermal expansion and contraction in tropical climates

Explanation:

Mechanical weathering is also known as physical weathering, and it entails the disintegration of rocks into smaller fragments.

Weathering processes generally take place slowly with time. Also, they are geography specific. One such means is frost action. In frost action, a freezing and thawing cycle catalyze rock disintegration. When water freezes, it expands 9 percent in volume. The expansion causes stress which forces rock disintegration.

Also, in some coastal and arid regions, salt crystals may grow from saline solutions on evaporation. When these salts crystallize in interstices of rocks, they produce stress and widen pores. This weathering process is very slow.  

Another very effective mechanical weathering process which occurs in tropical regions of the world is thermal expansion and contraction. It's a prolonged process in which daily heating and cooling of rocks cause a rock to expand during the day and contract at night. This alternating process causes cracks to open up in a rock body.