Lecture 5: Geomorphology Flashcards
What is an endogenic process?
Process driven by heat energy from beneath the earth’s crust.
What is an exogenic process?
A process driven by energy external to the mantle.
- Mainly solar energy
What are examples of endogenic processes?
Mountain building at convergent boundaries.
Volcanism at convergent/divergent boundaries.
- usually about creating landmass and increasing elevation
What is an examples of exogenic processing?
Chemical weathering
Movement of weathered materials (gravity, tides/ocean currents, wind, etc)
What is the geologic cycle?
Natural cycle of recycling earth’s minerals and elements over time.
What are the main types of rocks and their forming process?
Igneous - created by endogenic process (cooling magma)
Sedimentary - created by exogenic process (weathering & deposition & burial)
Metamorphic - created by exogenic process (deep burial with heat & pressure)
What are the chemical, physical, and biological weather processes?
Chemical: acid rain on silicate rocks
Physical: freeze-thaw cycles and frost wedging
Biological: root spreading
What are the processes that move sediments to shape landscapes?
Gravity (mass wasting), running water (fluvial), flowing ice (glaciers), along sea coasts (tides & waves), wind (eolian)
What is mass wasting?
Mass movement of eroded material due to gravity.
What is fluvial transport?
sediments transported by moving water.
How does fluvial transport work?
Rain allows water on land –> mountains concentrate precipitation & runoff –> erosion and fluvial transport move sediments around
What is the rain shadow effect?
Casting a rain shadow on one side of a mountain
- moist air hits a mountain is forced upwards where it cools and precipitates on that one side of the mountain only
What is a drainage basin?
Rainfall on a mountain drains with gravity into a drainage basin: erosion zone, then transport zone, then deposition zone.
What is an erosion zone?
where water forcefully erodes a landscape over time.
What is a transport zone?
Where little sediment from an erosion zone begins to collect - forms a meandering river system
What is a meandering river?
A river characterized by a winding path, with a single channel that curves and bends across a relatively flat landscape.
What are the three main types of sediments?
Dissolved load (ex: Ca+ ions)
Suspended load (ex: small yet visible mud particles suspended in water)
Bed load (large debris and rocks that roll/slide along the bed)
What is a deposition zone?
where the remainder of the sediments deposit (usually at a coastline)
What is an estuary?
A partially enclosed coastal body of water where freshwater and saltwater mix.
What is a delta?
A landform created at the mouth of a river where sediment is deposited.
