Question

The image shows an example of a sedimentary rock.

Large and small shells embedded in light colored rock.

Which feature of this rock demonstrates that it is an organic rock?

the varying sizes of its rock fragments
the visible pieces of sediment it contains
the ocean animals deposited in its layers
the crystals of dissolved minerals it contains

Answer 1

The feature of this rock that demonstrates it is an organic rock is **the ocean animals deposited in its layers**. Organic rocks, such as fossiliferous limestone, are formed from the accumulation of biological materials, such as shells and other organic remains. The presence of large and small shells indicates that the rock is composed of once-living organisms.