Transcript Birth of the Universe

Sediments
and
Sedimentary
Rocks
Sediments and Sedimentary Rocks
And
Sedimentary
Rocks
Metamorphic
Rocks
Weathering/Erosion
Heat and Pressure
Magma
Sediment
Igneous
Rocks
Sediments (soft)
Material (such as gravel, sand, mud, and
lime) that is transported by wind, water, ice,
or gravity;
Material that is precipitated from solution;
Deposits of organic origin (such as coal and
coral reefs).
Sedimentary Rock (hard)
Rock formed by the accumulation and
consolidation of sediment.
Sediments - unconsolidated
particles created by
1. The weathering of rock
2. The secretions of organisms or
decomposition of organic matter
3. Chemical precipitation
Sedimentary Rocks
Composed of lithified sediments
- by compaction
- by cementation
Two (Textures)
clastic (detrital)
non-clastic
Types of Sediments
Clastic
Non-clastic
1. Biochemical
2. Chemical
Igneous Rocks
Sedimentary Rocks
1. Phaneritic
1. Clastic
2 .Aphanitic
2. Non-clastic
* Glassy
* Vesicular
* Biochemical
* Chemical
Types of Sediments
1. Clastic – broken fragments of
rock produced by weathering.
Range in size from largest boulder
to smallest clay particle.
Classified according to size.
Found everywhere on the Earth.
Clastic Texture
Texture - Size, shape, and distribution of
particles that collectively make up a rock
•Size
•Rounding
•Sorting
Clastic Sediment Size
Clastic Texture
Roundness – the shape of sediment
grains.
Related to the distance a sediment has
been transported.
Roundness / Sphericity of
Sediments
Size
Rounding
Sphericity
Sorting
Clastic Sediments Sorting
Sorting – separation of sediments
by grain size and density.
Poorly sorted – sediment with a
wide range of grain sizes.
Well sorted – sediment with a
small range of grain sizes.
Sorting of Sediments
Sorting - a function of transported
1. Water
2. Wind
3. Glaciers
Texture and Transport
Distance
In general, as transport distance increases,
rounding and sorting increase.
Examples:
Breccia – cemented close to source
Conglomerate – transported then
cemented
Depositional Environments of Sedimentary Rocks
Smaller….Rounder…..Better Sorted
Clastic Sedimentary Rocks
Nonclastic Sedimentary Rocks
Basin
Source
Downstream
Beach
Offshore
(Playa Lake)
Halite, Gypsum, Chert
(Evaporites)
Coal
Reef
Swamp
Coquina
Limestone
Transport by Water
Saltation – particles move downstream in
short jumps.
Bed load – material transported by saltation
Suspended load – material carried in water
for long distances
Transport by Water
Sorting by Water
Graded Beds
Graded Beds
Fining
up
Sorting by Wind
Cross Bedding – water or wind
Sorting by Glaciers
Clast Size / Rock Name
Relationship
Large Clasts
Small Clasts
Breccia Formed at the source
Conglomerate –
Formed near the source
Sandstone –
Down stream to
just off shore
Tidal Flat Deposit
Stream Deposit
Off-Shore Environments
Strata
Stratum
Stratigraphy
Stratigraphic
- relating to layered
sedimentary rocks
Bedding – Layering or stratification
in sedimentary rock
Types of Sediments
2. Biochemical (non-clastic)
– composed of remains of plants
or animals.
Biochemical Sediments (non-clastic)
Terestrial Sediments - mainly plant matter
Marine Sediments - mainly carbonates
Corals - Large components of reefs.
Bivalves, Gastropods, Foraminifers - Whole or
partial skeletons form sand and gravels.
Aglae, Crinoids, Echinoderms, Bryozoans disintergrate to form some sand particles and
lime mud.
Diatoms, Radiolaria – Bedded chert SiO2
Coral (carbonate)
Foramanifera
Diatoms
Types of Sediments
3. Chemical (non-clastic)
– formed by minerals precipitating
from solution.
- Inorganic process, no biological
activity involved.
Bonneville Salt Flats
Chemical Sediments
(non-clastic)
1. Terestrial - Evaporites:
Gypsum - CaSO4 . H2O
Anhydrite - CaSO4
Halite NaCl
2. Marine Carbonates - CaCO3 (Whitings)
Sedimentary Rocks
Clastic Rock – composed of fragments
of preexisting rocks.
Non-clastic Rock – composed of
chemical precipitates or biogenic matter.
Ripple Marks
Mud Cracks
Burrows
Depositional Environments
Where sedimentary rock live!
Delta building into lake. SE Alaska.
small fan emerging from a wineglass canyon. Death Valley, CA.
Ripples on tidal flat, SE Alaska
Son-Kul River, Tien Shan Mtns., Kyrgyzstan
Peanut Brittle Conglomerate in Southern Illinois