Do Now Please take out your Web Quest

Do Now • Please take out your Web. Quest

Weathering, Erosion, & Deposition Learning Target: I can differentiate between weathering, erosion, and deposition and explain how they contribute to the various features of Earth’s landscape formations.

Weathering The natural wearing down of objects by elements in the environment. Erosion The process of transporting weathered material and always includes deposition of material Main agents of erosion: water & waves, wind, glaciers, and gravity – we will talk more about these later.

Mechanical weathering Physical breakdown of an object into smaller components WITHOUT changing its chemical composition Chemical weathering Breakdown of an object into particles WITH a different mineral composition than original object

Deposition Depositing weathered material and sediment in a different location from original position. Weathering, erosion, and deposition are responsible for continual reshaping of Earth’s surface.

How was the Grand Canyon formed? A Geological Timeline Oldest rocks at the bottom of the canyon ( 1. 6 – 1. 8 BYA) were once covered by mountains taller than the Himalayas.

How was the Grand Canyon formed? A Geological Timeline Hundreds of millions of years of erosion wore the mountain down to just hills just tens of meters tall.

How was the Grand Canyon formed? A Geological Timeline Ancient oceans dominated that area from about 1 billion years ago to about 80 million years ago.

How was the Grand Canyon formed? A Geological Timeline The rising and falling of the ocean deposited Sea shells Limestone Mud Shale Sandstone Time and pressure compressed the layers into

How was the Grand Canyon formed? A Geological Timeline About 70 to 80 MYA, subduction of the Pacific Ocean Plate under the Continental North American Plate caused an upwelling resulting in the Colorado Plateau and the Rocky Mountains.

How was the Grand Canyon formed? A Geological Timeline Meltwater runoff from the snow-capped Rocky Mountains pooled and formed the Colorado river about 5 to 6 MYA.

How was the Grand Canyon formed? A Geological Timeline The Colorado River is special because it drops 10 ft. for every mile it travels. It carries 500, 000 tons of silt, sand, and rocks downstream everyday. The abrasive force of the sediments acts like sandpaper and cut through the plateau to expose the rock layers. This contributed to the depth of the Grand Canyon (1. 6 km deep)

How was the Grand Canyon formed? A Geological Timeline Gravity took over with rain and ice chipping away at the canyon walls weathering the sides and erosion carried the sediments downstream.

How does the formation of the Grand Canyon tie into what we have been learning about in Bundle 3? We started with Pangea and asked “How have the various features of Earth’s landscape formed? ” LS 2 Plate Tectonics LS 3 Rock Layers LS 4 Convection & Density And now in LS 5 we are talking about weathering, erosion, and deposition. How does it all relate?

Four Main Agents of Erosion Gravity: Simple movement of sediment and rocks down slope from an area of higher elevation to an area of lower elevation. Accumulation of talus (pieces of broken rock) at the bottom of a mountain or hillside.

Four Main Agents of Erosion Glaciers: Movement of large masses of ice formed from compacted snow over time. • Plucking – picking up rocks • Abrasion - scraping the surface of rocks • Ice thrusting – pushing rocks forward Rocks can be broken down, worn down, gouged, carved, incorporated, and moved by glaciers.

Four Main Agents of Erosion Wind: Movement of small particles suspended in wind currents or movement of larger particles pushed and rolled along the ground (saltation). Movement depends on size of sediment particle, velocity of wind, and duration of wind current.

Four Main Agents of Erosion Water: Particles can be carried in water stream as • Dissolved load – particle in solution • Suspended load – particles carried without settling to bottom • Bed load – particles bounce off stream bed (saltation) Precipitation > Infiltration = sheet erosion of surface Precipitation impact Wave action Rills Gullies

Depositional Landforms Moraines: Any accumulation of till (unsorted sediment) melted out directly from the glacier or piled into a ridge by the glacier is a moraine.

Depositional Landforms Flutes: Also known as fluted moraine, these are elongate streamlined ridges of sediment that are produced beneath a glacier and which are aligned in the direction of ice flow. Created when the glacier flows around a boulder, creates a cavity that fills with muddy till, then deposit out in a long tail.

Depositional Landforms Continental Glacier: Similar to valley glacier formations, but can be much larger Drumlin - a streamlined, elongate mound of sediment deposited by continental glacier.

Depositional Landforms Glaciofluvial deposits Deposits formed by meltwater streams from glacier • Outwash plain • Esker • Outwash delta Glaciolacustrine deposits Sediments that accumulate at the margins and bottoms of glacial lakes and ponds

Minerals Mineral Identification: • Naturally occurring – not made by people • e. g. humans invented steel by creating a homogeneous mixture of iron and carbon, therefore steel is not a mineral • Inorganic – the substance is not made by an organism. • e. g. wood and pearls and made by organisms, therefore they are not minerals • Solid – not a liquid or gas at standard room temperature and pressure

Minerals Mineral Identification: • Definite chemical composition – consistent ration of chemical elements • e. g. Na. Cl • Ordered internal structure – arranged in a systematic and repeated pattern

Minerals Mineral Characteristics: • Hardness – ability to resist being scratched • Luster – how a mineral reflects light • Color – considered in identifying, but not used as a major identifying characteristic • Streak – the color of the powdered mineral (more useful for identification than whole mineral color) • Specific Gravity – ratio between mass of mineral and mass of an equal volume of water • Cleavage – the way in which a mineral breaks along smooth flat planes • Fracture – when mineral breaks irregularly • Tenacity – how well a mineral resists breakage

Forces of Nature Destructive, Constructive, or Both? Tornado Volcano Hurricane Earthquake

References [Chemical weathering]. (n. d. ). Retrieved April 19, 2018, from https: //www. thoughtco. com/examples-ofchemical-weathering-607608 [Drumlin]. (n. d. ). Retrieved April 19, 2018, from https: //www. pinterest. com/pin/53902526768367351/? lp=true [Flutes]. (n. d. ). Retrieved April 19, 2018, from https: //www. sheffield. ac. uk/drumlins/flutes [Glacier erosion]. (n. d. ). Retrieved April 19, 2018, from http: //slideplayer. com/slide/8152848/ [Glacuifluvial]. (n. d. ). Retrieved April 19, 2018, from https: //www. slideshare. net/wwlittle/glacial-systems How Was the Grand Canyon Formed [Video file]. (n. d. ). Retrieved April 19, 2018, from https: //www. youtube. com/watch? v=-v_RLRT 9930 [Minerals]. (n. d. ). Retrieved April 19, 2018, from https: //physicalgeology. pressbooks. com/chapter/5 -3 mineral-groups/ [Moraines]. (n. d. ). Retrieved April 19, 2018, from http: //glacierhub. org/2015/03/10/glacial-morainesinfluence-new-techniques-in-micro-biomedicine/ National Geographic Society. (2015, August 28). Forces of Nature. Retrieved from https: //www. nationalgeographic. org/interactive/forces-nature/ [Rivers Gullies Valleys]. (n. d. ). Retrieved April 19, 2018, from https: //www. clearias. com/erosion-depositionrunning-water-ground-water/ [Talus]. (n. d. ). Retrieved April 19, 2018, from https: //www. everythingselectric. com/ceres-erosion/ [Tree root]. (n. d. ). Retrieved April 19, 2018, from http: //www. kramertree. com/blog/tree-roots-structures/ [Weathering Erosion Deposition]. (n. d. ). Retrieved April 19, 2018, from Weathering Erosion Deposition [Wind erosion]. (n. d. ). Retrieved April 19, 2018, from http: //milford. nserl. purdue. edu/weppdocs/overview/images/flan 25. gif