Which phrases describe clastic sedimentary rocks? Check all that apply.

grouped by color

formed by mechanical weathering

grouped by size of rock fragments

formed from dead plants and animals

formed when rock fragments are squeezed together

-formed by mechanical weathering

-grouped by size of rock fragments

-formed when rock fragments are squeezed together

The correct answers are:

- formed by mechanical weathering;

- grouped by size of rock fragments;

- formed when rock fragments are squeezed together;

The clastic sedimentary rocks are made out of fragments of pre-existing minerals and rocks. The term clastic comes from the word clast, which basically means fragments of geological detratus, smaller grains and chunks of rocks that have been broken off from other bigger pieces of rock, as a result of physical weathering.

These rocks are classified by their grain size, texture, clast, and cementing material composition. The size of the grains varies a lot, from clay, through silt, gravel, cobble, up to boulder sized fragments.