Chapter 18

Geomorphology

Landscape Evolution: Topography is a Balance Between and Tectonic Uplift Topography is a Balance Between Erosion and Tectonic Uplift

in an area is the Relief

relief

We have about 7000 feet of relief between Boulder and the Continental divide. – The maximum difference between the highest and lowest elevation. • Relief and increase erosion

Mountains control weather Isostasy:

Mountains Have Roots s

a continuous area of s i

is a large mass of rock that

is an area of low relief typically is a large low-lying area of low

mountain mountain range valley basin

A projects above surrounding terrain. A high elevation and relief. A formed by and drained a single stream. A relief. In arid areas basins commonly have closed topography (no river outlet to the sea). • • • • Mountains and Valley Mountains

Horn Arête Vertical Cliffs Alluvial Fans – – – – Typically occur in ranges. Glaciated forms Desert Mountains • • • :

Horn

Mountain Landforms Deserts: Vertical Cliffs and Alluvial Fans (depositional flood plain)

(Glacial) (Active Water erosion) (Fault) Valleys (Basins)

U-shape V-shape Flat-floored Tectonic origin San Luis Valley Jackson Hole Great Basin

Valleys and Basins – – – – – – – River Valleys Tectonic • • U-shaped Valley: Glacial Erosion V-shaped Valley: Active water erosion Flat-floored Valley: Depositional Flood Plain Flat Floored Valley Colorado National Monument Canyonlands

is formed by near- are areas of deeply gullied Landforms is an asymmetric ridge in

Desert and Semi-arid hogback

A dipping sedimentary rocks as the Flatirons. A vertical, resistant . (Dakota Ridge) Badlands topography unsuitable for agriculture. • • • a

Cuest Hogback Hogback Cuesta Bad- lands Alluvial Fan U-shaped Valley V-shaped Valley Cuesta Hogback Badlands • • • • • •

Landform Terms

Relief Mountain Mountain Range Isostasy Valley Basin Horn Arête • • • • • • • •