Sedimentary rocks
What are Sedimentary Rocks?
Sedimentary rocks are rocks formed from layers of small pieces of rocks, minerals, and remains of plants and animals that get pressed together over a long time.
Definition.
Sediment is tiny broken pieces of rocks and organic matter that settle down in layers.
Example.
Sand on a beach.
Mud in a river.
Dust carried by wind.
How Sedimentary Rocks Are Formed.
Sedimentary rocks are formed through a process that happens in four main steps:
1. Weathering
2. Erosion & Transportation
3. Deposition
4. Compaction & Cementation
What is Sediment?
Sediment means small pieces of rocks, minerals, and remains of plants and animals that have been broken down by wind, water, or ice.
Key Points
Formed from layers of sediments pressed and glued together.
Made from broken rocks, minerals, and organic matter.
Soft rocks compared to igneous rocks.
Often have layers.
May contain fossils of plants and animals.
Formed by compaction and cementation.
Examples: Sandstone, Limestone, Shale, Coal.
Found near rivers, lakes, and oceans.
What is Cementation?
Cementation is the process where minerals in water act like glue and stick sediments together to form solid rock.
What is Compaction?
Compaction is the process where layers of sediments are pressed together by the weight of the layers above.
How water acts like glue in rocks.
Water has dissolved minerals
Water moves through sediments
Minerals harden and stick particles
Fun Fact
Many sedimentary rocks have fossils.