I is answer. Don't open link. It is most likeky unsafe.
Similar to the other types of muscle, smooth muscle contraction is caused by the sliding of myosin and actin filaments over each other. Calcium initiates contractions in a different way in a smooth muscle than in a skeletal muscle.
Smooth muscles use less energy to generate the given amount of force, can substain contractile force without fatigue & uses calcium from the sarcoplasic reticulum & extracellular space.
The answer is sediments because sediments break down and are every where on earth also break down due to weathering
