sedimentary rocks rocks

Sedimentary Rocks Rocks

Schwichtenberg

Sedimentary Rocks Pieces of solid material that have been broken

down over time by wind, water, gravity, and other natural processes

Sediments get cemented together – depends on weathering & erosion

How Are Sedimentary Rocks Classified?

Based on how they were formed

Three Main Groups of Sedimentary Rocks

1. Clastic (Detrital) Sedimentary Rock- Most common type of sedimentary rock- Clasts Present - Formed from loose sediment deposits on earth’s

surface

Three Main Groups of Sedimentary Rocks

2. Chemical Sedimentary Rock- Rocks formed by chemical weathering- Clasts not present- Change from one form to another- Change Mineral Content

Three Main Groups of Sedimentary Rocks

3. Organic Sedimentary Rock- Rocks formed from once living things- Organic Material – contain carbon

How are Sedimentary Rocks Classified?

Clastic vs. Chemical

clasts present clasts not present

particles visible particles not visible

Clastic (Detrital)Course

Conglomerate Breccia

Detrital Sedimentary Rock

Chemical Sedimentary Rock

Two Types of Weathering

Chemical Weathering

Occurs when minerals within a rock are dissolved or become chemically changed

Physical Weathering

Minerals that are chemically unchanged break along fractures or grain boundaries

Physical properties are changed

Results of Weathering

Clastic Sediments Rock & Mineral Fragments

Boulder Cobble Pebble

Sand Silt Clay

Sediment Particle Size Rock ExplanationBoulder Watermelon Breccia

/ConglomerateRounded to Angular

Cobble Orange Breccia /Conglomerate

Rounded to Angular

Pebble Grape Breccia /Conglomerate

Rounded to Angular

Sand Sandstone Sand Sized Grains

Silt Fine Grained mud

Siltstone Fine Grained

Clay mud Shale Fine Grained

Sediment Particle Size Rock ExplanationBoulder Watermelon Breccia

(Conglomerate)Rounded to Angular

Cobble Orange Breccia (Conglomerate)

Rounded to Angular

Pebble Grape Breccia (Conglomerate)

Rounded to Angular

Sand Sandstone Sand Sized Grains

Silt Fine Grained mud

Siltstone Fine Grained

Clay mud Shale Fine Grained

LARGEST

SMALLEST!

Erosion

Transport & Movement of sediments

Jebel Kharaz, Jordan

Four Main Methods of Erosion

1. Wind

2. Water

3. Ice/Glaciers

4. Gravity

Formation of Sedimentary Rocks

1. Deposition - When sediments are laid down on

surfaces or sink to bottom of bodies of water

- Sediments are settling out

Formation of Sedimentary Rocks

2. Burial

- Repeated deposition & layering over time

- Banding may occur

Formation of Sedimentary Rocks

Lithification3. Compaction

4. Cementation

Lithification

3. Compaction

- Squeezing out of fluids from intense pressure

- Causes a physical change

Lithification

4. Cementation

- Sediments come together to form a solid rock

HOW?Cementing materials carried in solution by water through pore spaces and between particles.

Have compaction and temperatures rise.

Causes a chemical & mineral change and particles join

Cementation

Sequence How Sedimentary Rock is Formed From Clastic Sediments

Sequence How Sedimentary Rock is Formed From Clastic Sediments