Unit Three - Rocks and Minerals - Sedimentary Rocks Flashcards
How is a Sedimentary rock formed (5)?
Accumulation of sediment that is derived from preexisting rocks and other materials.
(Lithification)
- Rock formed from different sediments
- Comes from many different rocks and other materials
- Builds Up
- Join together through compaction, cementation and/or chemical action
- Creates a rock!
Texture
When it comes to sedimentary rocks
The size, form and orientation of the CLASTS of a rock
Texture is the main factor of sedimentary rock identificication
Clast - Individual Fragment
What are Clastic Sedimentary Rocks?
Rock fragments that are compacted and cemented together.
The texture that identifies the type of rock.
What are Crystalline Sedimentary Rocks?
Rocks formed from Chemical Action
Ex: Halite or Salt
Bioclastic
Rocks that FORMS from the remains of plants and animals!
What are the three types of sedimentary rocks?
- Bioclastic
- Clastic
- Crystalline
What are three ways that a sedimentary rock forms
Under bodies of water
- Cementation
- Compactation
- Chemical Action
What is cementation?
Sedimentary Rocks
- When rock particles join together, there is water in between them
- Water Evaporates
- Remaining material glues the particles together.
What is compaction?
A reduction of volume in sedimentary layers due to the increasing weight of overlying sediemnts
(Rocks lose pore space and becomes tightly packed)
Chemical Action
- Dissolved Minerals
- Water Evaporates
- A Crystalline Mass of Fine Crystals (Crystalline Sedimentary) is formed
What are characteristics that help identify sedimentary rocks?
- Clastic Texture/Horizontal Layers
- Fossils