Which of the following sedimentary rocks is mechanically formed?

Mechanically formed sedimentary rocks are formed through the accumulation and compaction of pre-existing rock fragments or other mineral materials that have been transported by mechanical means such as water, ice or wind. Out of the given options, shale is the mechanically formed sedimentary rock. Shale is made up of compressed clay, silt, or mud that has accumulated and compacted over time. The particles in shale are usually too fine to see with the naked eye, and they have been transported by water, making it a mechanically formed sedimentary rock. Chalk and limestone are formed from the accumulation of the remains of marine organisms such as coral or shells. Coal, on the other hand, is formed from the remains of ancient plants and trees that have undergone a process of carbonization. These processes are not considered to be mechanical, so chalk, limestone, and coal are not mechanically formed sedimentary rocks.