Glossary AT 2 Flashcards
Weathering
Rocks being broken down into smaller pieces over a long period of time. Happens through natural processes (usually wind or water, temp changes, etc)
Erosion
Legit just weathering + the movement of the broken down pieces. Changes shape of land
Deposition
The end part of erosion - The movement of eroded materials has finished and have been deposited at a new location
Mass Wasting
A rapid form of erosion that works primarily due to gravity in combination with other erosional agents. It occurs very quickly and can result in either small or large scale changes to the landscape depending on the type of event.
Karst landscapes
Terrain shaped by dissolution of limestone or other carbonate rocks, resulting in features like caves, sinkholes, and underground rivers.
Forms cause of carbonation (usually)
Kinda like MC amplified world but realistic scale
Dissolution
The process of a substance being dissolved into a liquid, in geo referring to minerals or rocks dissolving in water.
Igneous rock
Forms from the cooling and solidification of molten rock (magma or lava).
Sedimentary rock
Formed from the accumulation and cementation of sediments like sand, silt, and shells.
Metamorphic rock
Formed when existing rocks are transformed by heat, pressure, or chemical reactions.
Silicate Materials
- A silicate material is a substance that contains silicon, oxygen and usually one or more metals.
- Very common in rocks and minerals (90% of all rocks in Earths crust)
(~95% of igneous rocks and a huge part of metamorphic and sedimentary rocks are silicate minerals)
Foliation
When metamorphic rocks form in thin layers (bands) due to pressure and heat.
These layers create ‘weak spots’ that make it easier for mechanical weathering (like freezing or plant roots) to break the rock apart.
Fracture + Fault + Joint
Fracture = a general term for any break/crack in a rock, meaning it includes both faults and joints
Fault = A fracture where the rock has clearly shifted, (could be up/down, or it slid sideways) caused by tectonic forces
Joint = A fracture where there is no movement on either rock - the rocks cracked, but hasn’t shifted at all. Caused by cooling, pressure release, weathering
Bedrock + Carbonic Bedrock
The solid, unbroken layer of rock that lies beneath the soil, sediment, and other surface materials + forms foundation of Earth’s crust.
Carbonic bedrock refers to bedrock thats made up of carbonate rocks (limestone, dolomite, etc) which reacts with carbonic acid. Carbonic bedrock is more susceptible to carbonation.
Pedestals/Mushroom rocks
Pedestals - rocks where the bottom half has been more heavily eroded than the top, kinda like an upside down triangle but not as drastic.
AKA mushroom rocks.
monadnocks are huge rising rock in an otherwise barren or very flat landscape
Inselberg/Monadnocks
Inselbergs are huge rising mountains/hills that rise sharply in an otherwise barren or very flat + gently sloping landscape. Uluru.
AKA monadnock
Bornhardt
A tall, large rock hill with a roundish pointy tip (like a -ve parabola), that forms when softer surrounding rock erodes, leaving tough rock (granite, gneiss, etc) behind as a hill which stands out in a flat area.
Somex bornhardts are inselbergs, and it only is one if its standing alone in an open, flat landscape
Runoff
Excess water that flows over the land’s surface, bc the ground can’t absorb it all. Happens after heavy rain and can carry soil, nutrients, or pollutants into rivers and lakes.
Rill
A rill is a small, very shallow stream of water formed on the surface of soil by running water. Usually temporary.
Like little streams of runoff
Gully
A ravine formed by water - deep, wide channels carved by concentrated runoff and erosion. Begin as rills but with more water becomes gullies.
More extreme version of rills
Arêtes
A sharp ridge that forms between two glacial valleys after glaciers erode both sides of a mountain. They are temporary; eventually they’ll erode.
mountain, E and W is eroded by glacier, leaves long, skinny, elevated part in middle thats travelling N-S. (ts part is the arete)
Plucking
When a glacier freezes onto a piece of rock (usually cracked or loosened), then carries the rock pieces along with it as it moves. It shapes rugged mountain valleys and adds broken rock to the glacier’s base
Glacial Striae/Striation
Long, narrow scratches or grooves left on rock surfaces by debris dragged along the base of a moving glacier. They show the direction the glacier was moving and how it shaped the land.
Angle of Repose
The steepest angle at which loose material like sand, gravel, or rocks can stay stable without sliding. If the slope becomes steeper than this angle, the material will start to slide down.
Unconsolidated materials tend to stabilize near an angle of 35° however this balance is easily disrupted by changes in environmental
conditions
Talus/Scree
Pile of broken/weathers rock fragments that collect at the bottom of cliffs/steep mountain slopes. Rocks fall due to the slope angle exceeding angle of repose, weathering, or gravity. Forms as a sloped heap at the bottom
