Answer: When limestone undergoes change in the pressure and temperature condition (or undergoes metamorphism), then it turns into marble. Limestone is a sedimentary rock whereas marble is metamorphic.
Fault line has no direct relation to the limestone formation. In order to form limestone, sediments and fossils must be deposited in a fluvial or shallow marine environment. This fault line if present during its formation, then it could have helped in the accumulation of the required sediments.
