Final answer:
Parallel structure, also known as stratification, is a characteristic of most sedimentary rocks. Stratification refers to the layering observed in sedimentary rocks, with different thicknesses and shapes. Ripple marks and cross-bedding patterns are examples of stratification.
Step-by-step explanation:
Parallel structure, also known as stratification, is a characteristic of most sedimentary rocks. Stratification refers to the layering that can be observed in sedimentary rocks, with thicker layers called beds and thinner layers called laminations. These layers can vary in thickness and shape, ranging from several millimeters to several meters. Examples of stratification include ripple marks and cross-bedding patterns.