1. Sediment: Loose minerals, rock fragments, or fossils
7. SEDIMENTARY ROCKS
Sedimentary Rock: Rock formed from sediments that are cemented together.
Sediment: Loose minerals, rock fragments, or fossils

2. PROCESSES OF FORMING DETRITAL SEDIMENTARY ROCKS
SmartFigure 7.2

3. SEDIMENTS SEDIMENTARY ROCKS Organic Detrital Chemical (A) (B) (C)
Searless lake, CA
Halite
(A)
(B)
(C)
Fragments of minerals/rocks
Mineral precipitates
Shells/Fossils
SEDIMENTARY ROCKS
Organic
Detrital
Chemical

4. (1) DETRITAL SEDIMENTARY ROCKS
Rocks that form from loose fragments of rocks (and minerals) at or near the surface of the Earth by processes that include:
Weathering,
Erosion/transportation,
Deposition (accumulation ), and
Diagenesis.

5. 1. WEATHERING : The disintegration and decomposition of rock
Mechanical weathering : breaking of rocks into smaller pieces
Chemical weathering: refers to the chemical reactions that alter or destroy minerals when rock comes in contact with water solutions or air
Weathered granite
Fresh granite

6. Features of weathered rocks

7. Feldspar WEATHERING OF FELDSPAR Acidified water containing (H+) ions
Alteration clay
Unaltered feldspar
Where K, Ca, Na, SiO2 have washed away, a residue of insoluble clay minerals remains.
Potassium ion (K+),
Calcium ion (Ca2+),
Silica (SiO2),
Sodium ion (Na+)
Feldspar

8. SmartFigure 6.13

9. Denver, Colorado
Guatemala
Devil's Hole near Hawthorne, Florida

10. SINKHOLE WARNING SIGNS
Structural cracks in walls and floors;
Doors and windows that don't close properly, which may be the result of movement of the building's foundation.
A circular pattern of ground cracks around the sinking area. Sudden earth cracking should be interpreted as a very serious risk of sinkhole or earth collapse.
Localized, gradual ground settlement or sudden ground openings;
Formation of small ponds, as rainfall accumulates in new areas;
Interrupted plumbing or electrical service to a building or neighborhood due to damaged utility lines;
Slumping or falling trees or fence posts;

11. CLIMATE & WEATHERING
Limestone in a dry desert climate are very resistant to weathering, but in a tropical climate weather very rapidly

12. 2. EROSION: the wearing away of rocks and their transportation by the action of water, ice, wind, etc

15. SORTING Sorting refers to the degree of similarity in grain size.
Poorly-sorted
Well-sorted

16. Grain Rounding: refers to the degree of sharpness of the grain edges

17. 3. DEPOSITION (Accumulation): the settling down of transported sediments in oceans, seas, lakes, on river banks, or foot of mountains.

18. CURRENT VELOCITIES REQUIRED FOR EROSION, TRANSPORTATION, & DEPOSITION

19. 4. DIAGENESIS : Includes
Cementation: deposition of dissolved mineral components in the openings between sediments
Lithification: hardening of sediments into rocks

20. PARTICLE SIZE CATEGORIES AND COMMON SEDIMENTARY ROCKS
Figure 7.3

21. 2. CHEMICAL SEDIMENTARY ROCKS
Evaporites: (1) Rock Salt (NaCl)
(2) Rock Gypsum (CaSO4.2H2O)
Precipitates:
(1) Limestone - from CaCO3 in sea water
(2) Chert - microcrystalline quartz forms from Si and O dissolved in water
Afar rock-salt mine, Ethiopia
Gypsum
Chert

22. AMERICAN ROCK SALT (Upstate NY) is the largest operating salt mine (main use as a de-icing salt) in the United States with a capacity for producing up to 18,000 tons each day.

23. TRAVERTINE CO2-rich water + Limestone Saturated Water [Ca(HCO3)2]
CaCO3
Drop in P Increase T
CaCO3 recrystallizes
Travertine
CO2 gas released

24. The Roman Coliseum (Colosseum)

25. Europe's longest (1,043m) castle in Burghausen (Germany), 1000 years old and mainly composed of travertine

26. THE GETTY CENTER
Brentwood,
Los Angeles, CA

27. The UCLA Medical Center Entire first floor has thick travertine walls

28. 3. ORGANIC SEDIMENTARY ROCKS
Fossiliferous Limestone: mostly calcite cement with some shells
Coquina: predominantly shells; Chalk when the shells are microscopic
Coal made of plant remains
Fossiliferous Limestone
Coquina

29. SIGNIFICANCE OF SEDIMENTARY ROCKS
Lucy: the oldest hominid fossil discovered
Dinosaur bone

30. Because sedimentary rocks contain fossils and other clues about the geologic past, they are important in the study of Earth’s evolutionary history.

31. ECONOMIC IMPORTANCE OF SEDIMENTARY ROCKS
Sedimentary rocks may contain
Fossil fuel: Coal, petroleum, natural
Ground water
Valuable minerals & industrial rocks: Halite, gypsum, gold, diamond, iron, aluminum, manganese, limestone
gas

32. Classify the following sedimentary rocks into detrital, chemical, and biochemical. Justify your answer.
ROCK SALT