landforms unit 11
TRANSCRIPT
Diapositiva 1
Unit 11. The evolution of landformsBiology and Geology. 4 ESOIES Antonio Gala
1. An overview of landforms
Landscape Vs. Landform(match both columns)1. LandscapeA. a naturallyformed feature on theEarths surface, having acharacteristic shape or form2. Landform B. visiblefeatures of an area includingboth the natural (mountains,forests, rivers etc) andhuman elements (roads,houses, bridges etc)
.Landforms of varying sizes and shapes, when taken together, are referred to as a landscape The landforms have relationships with each other, which means they form distinctive groupings in these different landscapes.Some landforms are extensive (dune fields) and others are small (group of rocks)Geomorphology examines landforms, concentrated on the surface of the lithosphere, and the processes producing them.
CHANGES ON RELIEF
External energyInternal energy
Sun energy and gravity
EXTERNAL GEOLOGICAL PROCESSESRelief destructionGeothermal energyINTERNAL GEOLOGICAL PROCESSES
Relief construction
ClimateLithologyHuman actionsTectonic plates dynamics
External geological AGENT
External geological PROCESS
LANDFORM of relief
The one who creates the reliefRiver, wind, sea, glacier, rain,The action to create the reliefWeathering, erosion, transportation, sedimentationThe resultdune, beach, valley, caves, cliff, The river erodes the mountain and as a result we have a valley
2. Lithological landforms
2.1. Volcanic landforms
What is this feature and what landform does it belong to?
Lithological landformsVolcanic landformsOriginal landform: lava fields
What is this feature and what landform does it belong to?
Lithological landformsVolcanic landformsOriginal landform: craters and conical edifices
What is this feature and what landform does it belong to?
Lithological landformsVolcanic landforms BASALT (VOLCANIC ROCK)Derived landform: lava plateau (Giants causeway in Ireland)
Columbia river plateau. Washington state. USA
Columbia river plateau. Washington State. USA
What is this feature and what landform does it belong to?Kaguyak volcano (Alaska) 2.5 km in diameter
Lithological landformsVolcanic landformsDerived landform:caldera (Yelowstone caldera)
Yellowstone National Park
2.2. Granite landforms
What are these features and what landform do they belong to?
Lithological landformsGranite landformsDomes (rounded blocks) and outcrops (straight blocks)Boulder (domes generally piled up)
Process of weathering in graniteStep 1At the beginning granite is already fractured in the subsurface. These fractures become more intense with the time and build a network that splits the granite into blocks of cube-like shape.
Step 2When the fractures come into contact with rain water, that seeps into the cracks. At night temperature decreases enough to freeze water into ice, which expands and breaks the corners. The building of boulders starts. The decay of the corners results in granite boulders of spheroidal shape.
Step 3: The last step is erosion of the decayed granite sand that exposes these spheroidally-weathered boulders at the surface.
2.3. karst landforms
What are these features and how are they produced?
Limestone carbonation
aSolid rockDissolved salt (solution)12DissolutionPrecipitation
What are these features and what landform do they belong to?
Lithological landformsKarst landforms: endokarstic landformsCaves or caverns (large cavities formed when smaller spaces join together due to the dissolution of limestone)Stalactites (precipitated calcium growing from the ceiling)Stalagmites (precipitated calcium growing from the ground)
Dissolution and precipitation of limestone
Evolution of karst landforms
What has happended here as time went by very slowly.?
Ceiling of caves can collape or dissolve completelyTorcal de Antequera (Mlaga. Spain)
Canyons
Torcas and RavinesWhich is each one?
3. Climate landforms
3.1. LANDFORMS IN COLD ZONES
Glacial landforms
GLACIER FORMATION1 It severely snows
GLACIER FORMATION2 The snow accumulates in the cirque and it is transformed into ice because of its weight and low temperatures
cirque
GLACIER FORMATION3 Due to the weight the ice goes down and forms the TONGUE
tonguecirque
GLACIER FORMATIION4 On its way down the glacier erodes and transports materials (sediments).
cirquetongue
GLACIER FORMATION5 when the ice melts, rivers are formed and materials are deposited forming moraines
cirquetongueterminus
GLACIER FORMATION6 The glacier disappears thousands of years later but the landforms remain.
cirqueGlacial cirqueU-shaped valley
TaskWrite the name of the landform, agent and process of the following photos.
Glacial cirque Glacier Erosion
Glacial lake Glacier Erosion
Rocks with glacial striations GlacierTransportation
Valle de OrdesaU-shaped valley GlacierErosion
Till /Morrains GlacierSedimentation
3.2. LANDFORMS IN TEMPERATE ZONES
Dry temperate zones: Semi-desert landforms
Gullies, torrential rain, erosion
Morocco
Utah USAHoodoo or fairy chimneys / Torrential rain / Weathering and erosion
Fluvial landforms
Water fall RiverErosion
V-shaped valley RiverErosion
Delta RiverSedimentation
Gorge RiverErosion
MeandersRiverErosion/Deposition
3.3. LANDFORMS IN HOT ZONES
Desert landforms
Mushroom-shaped rock, Wind, Erosion
Crescent (Barchan) Dunes, Wind, Deposition
What is this feature and what landform does it belong to?
What is this feature and what landform does it belong to?
Star Dunes, Wind, Deposition
Arches, Wind, Weathering & Erosion,
4. Structural landforms
What are these features and what landform do they belong to?
Structural landformsLandforms in horizontal regions: table mountains or plateaus, monadrocks or isolated ridges
What are these features and what landform do they belong to?
Structural landformsLandforms in folded regions: hills and crests
What are these features and what landform do they belong to?
Structural landformsLandforms in fractured regions: horst and graben
________ fault?
5. Coastal landforms
Cape /baySeaErosion
CliffSeaErosion
Wave-cut platformSeaErosion
Zumaia, Euskadi
cliffcliffcliffcliffseaseaseaseaEroded materialsAbrasion platformAbrasion platform
Las catedrales, GaliciaArchesSeaErosion
Mar Menor (Murcia)LagoonSeaSedimentation (sand bar)
DoanaMarshSeaSedimentation (in an estuary)
T H E E N D