sedimentary

Everyday

1. Sedimentary rock is rock made from layers of sand, mud, shells or tiny bits of other rock that are pressed together over a very long time. tree →
2. Sedimentary means made from sediment, the bits that settle at the bottom of water. tree →

In the lessons

In science lessons there are three main types of rock: igneous (from melted rock), sedimentary and metamorphic (changed by heat and pressure). Sandstone, limestone, chalk and shale are sedimentary rocks; fossils are mostly found in them. In the rock cycle, rocks are worn down, carried by rivers and laid down as layers.

Examples

• Sandstone is a sedimentary rock. tree →
• Fossils are often found in sedimentary rocks. tree →
• The cliff showed many sedimentary layers. tree →
• Chalk is a soft sedimentary rock made of tiny shells. tree →
• Sedimentary rocks form at the bottom of seas and lakes. tree →
• The oldest layers are at the bottom of sedimentary rock. tree →

Note

A science word; no comparative. Related: sediment (the bits), sedimentation (the settling). Sedimentary rocks are often softer and can crumble; igneous rocks like granite are usually harder.