Sedimentary RocksMost Sedimentary Rocks: Sediments are eroded
from rocks, perhaps transported, deposited, then compacted and lithified (hardened and turned into a
sedimentary rock).
A Sedimentary Rock is…..
rock formed from the lithification or crystallization of:
1. Minerals in solution2. Organic remains3. Materials produced by living things
(biochemical)4. Clastic Sediments (rock fragments of all
sizes)
So Sedimentary Rocks form through compacting and cementing of sediments.
Lithification-to harden and form rock (Deposition, Compaction, Cementation)
Silica Crystals
Crystallization- Solidification of dissolved minerals from solution.
Sediment- Rock fragments, dissolved minerals and remains of living and nonliving parts of
plants and animals.
Lithification: Step 1 - Deposition
Deposition (to lay down) happens when:
the Transport Agent no longer has the energy/force required to carry the Sediment
Determined by:
Size/Weight of Sediments
Amount of Energy/Force in Transport Agent
Lithification: Step 2 - Compaction
Lithification: Step 3 - Cementation
Types of Sedimentary Rocks(Classified by formation)
• Clastic-Made of fragments of other rocks.
• Chemical-Made from dissolved minerals.
• Biochemical-Made by living things, but was never alive (seashells).
• Organic-Made of the organic remains of living things.
Clastic Sediments- Fragments of pre-existing rock.
Sediments from here
Alluvial Fan
Alluvial Sediments and braided stream
Gravel Bar
Tallus Pile
Glacial Sediment
Sand Bar
Chemical Sediments- Minerals in solution in water.
Biochemical Sediments- Nonliving remains of plants and animals.
Organic Sediments-remains of the living tissues of plants and animals.
Peat- Plant remains
Examples of Sedimentary Rocks
Clastic Sedimentary Rocks
• Clastic-Made of fragments of other rocks.
Clastic Sedimentary Rocks
Claystone
Conglomerate
Shale
Clastic Sedimentary Rock Names: Particle Size
Sediment
Gravel Sand SiltClay
Conglomerate Sandstone Siltstone Shale
Clastic Sedimentary RocksConglomerate and Breccia – have gravels and cobbles
(Coarse-grained)
(Conglomerates have rounded
clasts)
(Breccia has angular clasts)
Clastic Sedimentary Rocks Sandstones – have sands (fine to coarse grained)
Arkose
Clastic Sedimentary Rocks Siltstones – have silts (fine-grained)
Clastic Sedimentary Rocks Mudstones – have clays (very fine-grained)
Sedimentary Rocks of Chemical Origin
• Chemical-Made from dissolved minerals.
Chemical Sedimentary Rocks: Precipitation and Evaporation
Chemical Sedimentary Rocks: Evaporites
Gypsum
Halite
Chemical Sedimentary Rocks: Evaporites
Salt Flats
Chemical Sedimentary Rocks: Carbonates
The Carbonate Sedimenatary Rocks are composed of mostly Calcium Carbonate.
The Carbonates are divided into:
Inorganic Carbonates (chemical sedimentary rocks)
And
Biochemical Carbonates (contains remains of living things)
Chemical Sedimentary Rocks: Inorganic Carbonates
Travertine
Chemical Sedimentary Rocks: Inorganic Carbonates
Chemical Sedimentary Rocks: Inorganic Carbonates
Travertine
Travertine Stalactites
Chemical Sedimentary Rocks: Inorganic Carbonates
Chemical Sedimentary Rocks: Inorganic Carbonate
Travertine
Chemical Sedimentary Rocks: Inorganic Carbonates
Inorganic Limestone
Chemical Sedimentary Rocks: Biochemical Carbonates
Biochemical-Made by living things, but was never alive (seashells).
Stromatolitic Limestone –(remains of photosynthetic process of algal blooms)
Biochemical Limestone –(shells)
Chemical Sedimentary Rocks: Biochemical Carbonates
Biochemical Limestone
Chemical Sedimentary Rocks: Biochemical Carbonates
CoquinaChalk
Chemical Sedimentary Rocks: Silica-based Sedimentary Rocks
Chert (Flint) Nodules
Geodes
• Organic-Made of the organic remains of living things.
Sedimentary Rocks of Organic Origin
Organic Sedimentary Rock - CoalPeat
Sediments Are Classified Based On:
1. Origin and Composition (What
they are made of).
So Remember . . .
Clastic
Sediments Are Classified Based On:
2. Size of the sediment (clastic sediments range in size from clay to boulders)
Sediment Classification II
Gravel
Pebbles
Sand
Sediment Production
Sediments are produced by:
Weathering (breaking down) and Erosion (transport) of
Parent material
by:
Chemical and Physical Processes.
Sediment Transport
WindWater
GlaciersGravity
Volcanic Eruption
Shaping of Sediments
Sorting of Sediments
Sediments are Sorted by their Transport Agents According to:
S I z e of the Sediment
Very Poorly Sorted Very Well Sorted
Sorting of Sediments
Well or poorly sorted??
• Well or poorly sorted??
Well or poorly sorted??
Sorting of Sediments: Glaciers
Sedimentary Rock Structures
Fossils: Molds
Fossils: Casts
Trilobite
Sedimentary Rocks are identified by their horizontal layers
called…….
Sedimentary Formations
Cross-Bedding
Bedding Planes not Parallel
Ripple Marks
Beach
River
Mud Cracks