Clastic and Biochemical (quiz)

clastic sedimentary rocks

range from conglomerates/breccias to shales

form near Earth’s surface

form from pieces (clasts) of pre-existing rocks

mudrocks/shales

The most abundant sedimentary rocks

clay-sized sedimentary particle

measures less than 1/256 mm

well sorted

an aggregate of sediment consists of particles that are all about the same size

breccia vs conglomerate

the particles are more angular in a breccia

Chalk

forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates (coccoliths) shed from micro-organisms called coccolithophores

All sedimentary rocks form:

At or near Earth's surface

Which is best classified as a biochemical (organic) sedimentary rock?

Fossilferous limestone that is made of calcite extracted from seawater by marine organisms.

coal

a sedimentary rock that form from the accumulation of plant remains.

quartz

most common mineral in sand