Classification of Sedimentary Rocks
- Created by: SophieDaniel
- Created on: 28-12-15 12:12
View mindmap
- Classification of Sedimentary Rocks
- Breccia
- Coarse Grains
- Clastic (composed of pre-existing minerals and rocks)
- Angular
- Some finer grains set in a matrix
- Poorly Sorted
- Commonly formed as scree/alluvial fans
- Volcanic breccia are pyroclastics from an eruption
- Conglomerate
- Coarse grains
- Clastic (composed of pre-existing rocks and minerals)
- Rounded (transported for longer)
- Finer grained matrix
- Poorly sorted
- Commonly formed in beach or river channel
- Sandstones
- Main rock for oil reservoirs and aquifers of water
- Building stones
- Well cemented - low porosity
- poorly cemented - high porosity
- quartz is the main component
- Mica, muscovite, k feldspar are common
- Found in all sedimentary environments
- Orthoquartzite
- A type of sandstone
- Only quartz grains in a quartz cement
- Well sorted
- Well rounded (transported for longer)
- Less stable minerals not present - well weathered
- Common in beach or shallow marine deposits
- Desert Sandstone
- Not fully quartz, iron oxide coats the grains
- Very well sorted
- Very well rounded
- 1mm grains
- Red in colour
- Class cemented by silica or iron minerals
- Form in arid environments as wind blown sands
- Arkose
- Medium to coarse grained
- At least 25% potassium feldspar
- Moderately sorted
- Sub angular to sub rounded grains (not transported far)
- Commonly formed in alluvial fan environments in arid areas
- Greywacke
- Fine to coarse grains
- Dark colour
- Poorly sorted
- Angular to sub angular
- Mainly rock fragments (lithic clasts)
- >15%of the rock is clay matrix
- Commonly formed as turbidite deposits - often show graded bedding
- Breccia
Similar Geology resources:
Teacher recommended
Comments
No comments have yet been made