Exogenic Processes PDF

ENDOGENIC PROCESSES Weathering, Erosion, Mass Wasting, Deposition TODAY’S FOCUS Weathering Erosion Mass Wasting Deposition  EXOGENIC PROCESSES Processes occurring on the Earth's surface and that generally reduce relief. These processes include weathering and the erosion, tran...

ENDOGENIC PROCESSES Weathering, Erosion, Mass Wasting, Deposition TODAY’S FOCUS Weathering Erosion Mass Wasting Deposition  EXOGENIC PROCESSES Processes occurring on the Earth's surface and that generally reduce relief. These processes include weathering and the erosion, transport, and deposition of soil and rocks; the primary geomorphic agents driving exogenic processes are water, ice, and wind.  WEATHERING It is a process where rocks, soil and minerals are broken down or worn away over time by natural elements like wind, water or even plants and animals. It can take many years and is essential in shaping our Earth’s landscapes. TYPES OF WEATHERING Mechanical Involves the physical breakdown of rocks without change in their chemical composition TYPES OF WEATHERING Chemical Involves the change in composition and structure of rocks and minerals through chemical reactions TYPES OF WEATHERING Biological Breakdown of rocks through the activities of organisms, such as plants and burrowing animals  WEATHERING CHALLENGE Identify whether each example exhibits mechanical, chemical or biological weathering. CHEMICAL BIOLOGICAL MECHANICAL Rounded rocks and Squirrels dig and Carbonic acid Sand dunes and pebbles alongside create burrows in forms the rock formations a riverbank rocky areas shapes observed shaped by winds in caves ANSWER KEY WEATHERING CHALLENGE Identify whether each example exhibits mechanical, chemical or biological weathering. MECHANICAL BIOLOGICAL CHEMICAL MECHANICAL Rounded rocks Squirrels dig and Carbonic acid Sand dunes and and pebbles create burrows in forms the rock formations alongside a rocky areas shapes observed shaped by winds riverbank in caves  EROSION It is a process where natural forces like wind, water or ice transport rocks, soil and other materials on Earth’s surface. Moving air and water can deposit these materials in new locations.  EROSION IN ACTION! Let’s take a look at some real-life examples of erosion around us. The Twelve Apostles in Victoria, Australia Ocean waves and winds gradually carved out caves and arches in the limestone cliffs, ultimately forming these sea stacks.  EROSION IN ACTION! Let’s take a look at some real-life examples of erosion around us. Nitmiluk National Park, Northern Territory The Katherine River has carved out this stunning deep gorge over millions of years. MASS WASTING Bulk displacement of soils and rocks downslope due to the action of gravity. Can be differentiated based on the rate and direction of the movement. TYPES OF MASS WASTING Creep Downward movement of the ground. Over a long period of time occurrence. TYPES OF MASS WASTING Fall Happens in very steep and almost vertical slopes. TYPES OF MASS WASTING Slide occurs when a portion of the soil or rock along a steep slope suddenly gives away and moves downhill, usually aided by heavy rainfall. Sliding mass movement occurs on slopes weakened by weathering such as landslides, rockslides, and mudslides. TYPES OF MASS WASTING Flow Happens rapidly due to waterlogged soil particles that move with it. Happens after extreme and prolonged rainfall. TYPES OF MASS WASTING Slump a type of slide (movement as a mass) that takes place within thick unconsolidated deposits (typically thicker than 10 m). TYPES OF MASS WASTING Spread the complex lateral movement of relatively coherent earth materials resting on a weaker substrate that is subject to liquefaction or plastic flow. TYPES OF MASS WASTING Topple Topple failures involve the forward rotation and movement of a mass of rock, earth or debris out of a slope. DEPOSITION general term for the dislodgement and downslope transport of soil and rock material under the direct application of gravitational body stresses  TYPES OF DEPOSITION Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rain wash, sheetwash, slow continuous downslope creep, or a variable combination of these processes.  TYPES OF DEPOSITION Alluvial is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings.  RACE AGAINST TIME Have you ever wondered how long it takes for a rock to weather or for soil to erode? Weathering Erosion Weathering can happen over various Erosion can also happen quickly timescales, from a few years for softer during a storm or over millions of materials like soil and sandstone to years due to slow processes like millions of years for harder rocks. wind and water erosion.  REVIEW Weathering Types of Race and Erosion Weathering Against Time Weathering is the Weathering can be Weathering and breakdown or decay of categorised into three: erosion can occur fast rocks, soil and minerals mechanical, chemical or for softer materials like at the place where they biological. soil or over millions of are found. years for harder rocks like granite. transport Erosion is the of broken down materials or soil from one place to another.