4-3 Flashcards
weathering
The breakdown of rocks into smaller particles called sediments
differnt kinds of physical weathering
Frost wedging, abrasion, Root action, exfoliation
frost wedging
Repeated freezing
And thawing of
Water in the cracks or rocks (pot holes)
abrasion
Bumping and rubbing of rocks as they Collide. Rocks become smaller, smoother
rounder (pebbles forming near water)
root action
Roots grow into and under
Rocks. Roots pry the rook apart (cracks in concrete)
exfoliation
Granite at the surface under less pressure
Expands and breaks
chemical weathering
A change in the rock that forms a new compound
Occurs on the surface of rock materials
kinds of chemical weathering
oxidation, carbonation, hydration
oxidation
Iron atoms combine
With oxygen to form
Ironoxide (rust)
carbonation
Acid dissolves rocks
Containing the
Imeral calcite (Limestone bedrook dissolves
When its in contact with acid groundwater
Forming caves and sinkholes)
hydration
Water weakness
Some minerals in rocks
(Feldspar becomes
Clay after
Long exposure to
water)
soil
The mixture of weathered rocks and biological activity over long periods of time
layers of soil
Dark brown to black soil with high organic content
Tan to orange soil with high clay content, some rock fragments
Light gray to black soil, coarse rock fragments
Residual soil
Soil that has not been eroded (transported)
Similar mineral content in soil and parent bedrock
transported soil
Soil that have been eroded and deposited in a new area
Made of completely different material than underlying bedrock
Typical soils of new York due to past glaciation
streams
Any body of water with a current (brooks,creeks,rivers)
- Moving water is the most erosive force on earth - Always flows downhill
tributary river system
A system that flows into a larger system
watershed river system
The geogrpahic area drained by a particular river or stream
Dendritic (drainage system)
Most common stream pattern, Found on flat surfaces
Looks like tree branches
Radial (drainage system)
Forms on a volcano or mountain top, Looks like spokes on a wheel
Annular (drainage system)
Occurs on an eroded dome, Circular pattern
Rectangular (drainage system)
Occurs along folds and faults
(looks like parallel liens with lines going into each path)
Solution (How sediments transported in a stream)
are dissolved (salt)
Suspension (how sediments transported in a stream)
Sediments remained mixed in with the after for a long time
Flotation (how sediments transported in a stream)
Sediments float on water
traction (how sediments transported in a stream)
Sediments roll on the stream bed
Ways sediments are transported in a stream
soultioun, suspension, flotation, traction
stream gradient
Steepness of land stream flows down
stream discharge
The volume of water flowing past a fixed point in a given period of time
Velocity
As the water velocity slows down, sediments begin to settle out and deposition increases
shape
Rounder particles settle faster than flatter
size
Larger particles settle faster than smaller particles
Density
Most dense particles settle faster than less dense particles
Horizontal sorting
When a stream enters a large body of water, the velocity of the stream slows and the largest particles
Settle out first at the mouth of the stream
vertical sorting
Sorting of sediment from bottom to top in still water
Largest, roundest, most dense particles settle out first and are on the bottom
Often occurs after a major event (landslide, volcanic explosion, earthquakes, hurricanes)
gradded bedding
A series of depositional events that occur at different
times
You can count the events by counting the beds
Erosion
transportation of sediments
agent of erosion
the force that moves sediments (gravity, water, wind, or ice)
Deposition
release or settling of weathered rock material by water, wind, ice, gravity, and waves.
Agent of Deposition
the force that drops sediments, usually when it slows down
sorted sediments (how they’re deposited)
when larger, more dense, rounder particles settle out first
unsorted sediments (how they’re deposited)
when sediments drop out in no particular order (all mixed up)
Mass movement
Downhill movement of rock or sediment without being carried by wind,
water, or ice. Caused directly by the force of GRAVITY
sediment evidence
Sediments that were eroded by gravity are unsorted and angular
How does wind deposit sediments?
Picks up small particles, such as sand, silt, and clay and carries them to different
locations.
wind abrasion
Rocks and sediments eroded by wind tend to have a frosted and
pitted appearance
ventifacts
wind-worn rocks that have flat surface
Barrier islands
Long, narrow strips of sand forming islands that protect inland
areas from ocean waves and storms (Jones Beach, Fire Island)
