Chapter 18
Geomorphology
Landscape Evolution: Topography is a Balance Between Erosion 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 ridge formed by near- are areas of deeply gullied Landforms is an asymmetric ridge in
Desert and Semi-arid cuesta hogback
A dipping sedimentary rocks as the Flatirons. A vertical, resistant sedimentary rock. (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 • • • • • • • •