LESSON 7 Geological Processes on Earth.pptx

Exogenic Processes

1. Geologic Processes on Earth

2. Geological processes are natural mechanisms that shape the Earth’s surface and interior.

3. Geological p rocesses Geological processes are dynamic actions or events at the Earth’s surface caused by natural forces like gravity, temperature changes, freezing and thawing, chemical reactions, seismic activity, wind, and moving water, ice, and snow. When these forces exceed the strength of Earth materials, they cause deformation, movement, or chemical changes. These processes can also interact with external factors like impact cratering and vary in importance over time and location on a planet’s surface.

4. Geological processes are divided into two main categories: Exogenic Processes Endogenic Processes

5. Exogenic Processes

6. Exogenic Processes it is formed or occuring on the surface of Earth i t is usually driven by gravity, water, wind, and organisms.

7. Types of Exogenic Processes a. Weathering b. Mass Wasting c. Erosion and Transportation d. Sedimentation

8. W EATHERING It is the process of disintegration and decomposition of rocks , soil and minerals.

9. W EATHERING There are three types of weathering: Physical or Mechanical Weathering Chemical Weathering Biological Weathering

10. 1. Physical or Mechanical Weathering - is a breakdown of rocks by mechanical forces Types of Weathering

11. Physical or Mechanical Weathering ICE/ FROST WEDGING Ice wedging is a form of mechanical weathering or physical weathering in which cracks in rock or other surfaces fill with water, freeze and expand, causing the cracks to enlarge and eventually break.

12. FACTORS THAT AFFECT PHYSICAL WEATHERING ICE WEDGING ~> H 2 O s e e ps i n r o c k , e x p a n ds, c r a c k r o c k s into s m alle r pieces. RELEASE OF PRES S U R E ~> Surface r o c k e r o d es, roc k fla k es li k e o n ion la y e r s. GR O WTH OF PLANTS ~> R o ots g r o w into crac k s a n d p u sh r oc k s a p a r t. A N IMALS ~> Bur r o w an d push a p a r t r o c k . A B R A S I ON ~> San d an d r o c k carrie d by wi n d, w a te r , i c e w e a r s a w a y s u r face r o c k w h e n r o c k s collide. Mos t com m o n in win d y a r e a s

13. 2. Chemical Weathering the changes in the composition of rocks due to the chemical reactions below: dissolution hydrolysis oxidation Types of Weathering

14. Chemical Reactions Affecting Chemical Weathering DISSOLUTION is the process by which rocks break down by chemical reactions. Weathering by water Ex. Halite the formation of stalactites and stalagmites in caves are brought about by this chemical reactions.

15. Chemical Reactions Affecting Chemical Weathering S talactites and S talagmites Halite Tafoni

16. HYDROLYSIS The chemical breakdown of a compound due to reaction with water. When rocks sit in water for extended periods of time they begin to break down and have a clay-like texture. Chemical Reactions Affecting Chemical Weathering

17. OXIDATION the response of oxygen with minerals. if the iron oxidizes, the mineral in rock descomposes. rusting is an example of this chemical reaction. Chemical Reactions Affecting Chemical Weathering

18. FACTORS THAT AFFECT CHEMICAL WEATHERING W A TER ~> W ater dis so l v es rock che m i cal l y . OXY G EN ~> Rock s that ha s iron in it mi x e s with ox y ge n an d rusts. CARB O N DIOXIDE ~> CO2 diss olves in ra i nwat er an d weat hers marble an d l i mest o ne. LIVING OR G ANIS M S ~> Aci d s from p l a nts and roots ch emic a l l y we ather ro c k. ACID RAIN ~> Air pollutio n reacts with clouds an d fa l l s on rock as acid ra i n.

19. 3. Biological Weathering - occurs when living organisms cause rocks to weather , or break down. - is the weakening and subsequent disintegration of rock by plants, animals and microbes. Types of Weathering

20. This refers to the movement of large masses of materials down a slope or a steep sided hill or mountain due to the pull of gravity. Debris flow, Mudflow, Slump examples are fall, slide, avalanche, and flow. Mass Wasting

21. Fou r main classes of Mass Wasting Falls Slides Creeps Flows. Mass Wasting

22. 1. Falls - This type of mass wasting can involve a single rock or thousands of rocks. For a mass wasting event to be classified as a fall, it must travel at a high rate of speed down a very steep slope Fou r main classes of Mass Wasting

23. 2. Creeps In geology, slow downslope movement of particles that occurs on every slope covered with loose, weathered material. Fou r main classes of Mass Wasting

24. 3. Slides A slide happens when a section of soil or rock suddenly gives way and moves down a slope. Fou r main classes of Mass Wasting

25. 4. Flows - A flowing mixture of debris and water, usually moving down a channel. Fou r main classes of Mass Wasting

26. DEBRIS FLOW - Happens when large amount of sediments, usually rocks of various sizes, falls down the slope. Flows

27. MUDFLOW - Happens when combined soil and water flow down a slope. Flows

28. SLUMP - Is a slow movement of soil along with a curved surface. - A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a slope. Movement is characterized by sliding along a concave-upward or planar surface. Flows

29. Erosion - It is the process by which earth’s surface is worn away by wind, water, or ice. - Process of erosion moves rock debris or soil from one place to another.

30. EROSI O N BY W A TER Erosion by w a t er changes the shape of coastlin e s. W av e s constan t ly cr a sh against shores. T h ey p o u n d rocks i n to pe b b l es and reduce peb b les to sand. W ater sometimes tak e s sand a w a y from beach es . T h is moves the coastline farther i n lan d .

31. EROSI O N BY WIND Ero s ion by w i n d carries dust, s an d , and v olcanic ash from one place to an o the r . W ind can somet i mes blow s a nd into to w ering d u n e s.

32. EROSI O N BY ICE Eros i on by ice can erode the la n d. In frig i d ar e as and on some mou n taint o p s, g l acie r s move sl o w ly d o w n h i l l and ac r oss the lan d . As they move, they pick up ever y th i ng in t h eir path, from ti n y grains of sand to h u ge b o u l ders.

33. EROSI O N BY GR A VITY Gravity p u l ls any l o ose b i ts d o w n the side of a h i ll o r mou n tain. Gravity Erosion is better kn o w n as Mass Movem e n t.

34. - It is the accumulation of materials such as soil, rock fragments and soil particles settling on the ground. SEDIMENTATION / D EPOSITION