Geography Exam 3 Chapter 14
Karst Topography
limestone region with a specific landscape of pitted, bumpy surface topography, poor drainage, & well developed solution channels underground (due to chemical weathering)
Debris Avalanche
mass of falling and tumbling rock, debris, and soil
Slope Erosion
material loosened by weathering susceptible to erosion and transportation, for material to move downslope forces of erosion must overcome other forces (friction, inertia & cohesion of particles to one another)
Unstable Slope
materials are weaker than the weathering and erosion processes (steep slope, sand soil)
Mudflow
more fluid than earthflow
Water content in the slope material is highest during which of the following types of mass movement? a)Mudflow b)Earthflow c)Rockfall d)Debris avalanche e)Translational slide
mudflow
Landscape System
open b/c has inputs of energy and materials, inputs are water from precipitation, rocks from tectonic activity
Exfoliation occurs because a)water combines with minerals and increases their size, thereby causing surrounding minerals to pop out of the rock matrix b)water freezes in joints and expands c)overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture d)All of the above are possible causes of exfoliation
overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture
Bedrock
parent rock from which weathered regolith and soils develop
Mass Movement Mechanics
physical and chemical processes weaken surface of landscape and make it more susceptible to pull of gravity
Geomorphic Threshold
point at which there is enough energy to overcome resistance against movements
Uplift of the landscape creates ___________energy which is converted to _________energy when materials begin to move downslope. a)kinetic; potential b)potential; kinetic c)potential; chemical d)kinetic; chemical
potential; kinetic
Climatic Conditions
precipitation, temperature, and freeze-thaw cycles, physical weathering in drier/cooler climates, chemical weathering in wetter/warmer climates
Weathering
process breaks down rocks by disintegrating into mineral particles or dissolving into water
Subsurface Water
promotes weathering from below by acting slowly and decomposing near-to-surface rock material
In most areas, the upper surface of bedrock is partially weathered to broken-up rock called a)parent rock b)bedrock c)sediment d)regolith
regolith
Potential Energy
related to elevation
Kinetic Energy
related to motion
Frost Wedging
repeated freezing (expanding) and thawing (contracting) of water is frost action, or freeze-thaw, breaking rocks apart
Angle of Repose
represents balance between driving force (gravity) and resisting force (friction and shearing)
Physical Weathering
rock breakage without any chemical alteration
Pressure-Release Jointing—Exfoliation Process
rocks peel or slip-off in sheets instead of breaking up into grains, removal or shedding of an outer layer by a pressure release from the removal of an overlying rock
Human-induced mass movements produce a category of processes known as a)debris flows b)denudation c)scarification d)translational slides
scarification
Geomorphology
science of landforms including origin, evolution, form, and spatial distribution of landforms
Exogenic processes develop...
sequential landscapes (low relief, gradual change, and stability)
A slow, persistent mass movement of surface soil is called a)a debris avalanche b)soil creep c)a soil slide d)a rock fall
soil creep
Earthflow
soil is saturated, flow will occur
Stable Slope
strength exceeds the weathering and erosion processes (gentle slope, hard rock)
Landslide
sudden rapid movement of a cohesive mass of regolith or bedrock that is not saturated with moisture (traditional or rotational)
Rockfall
volume of rock that falls through the air and hits a surface
After a threshold is crossed, the landscape a)remains unstable there after b)adjusts to a new equilibrium condition c)looks identical to the landscape that existed prior to the crossing of the threshold d)Any of the above are equally likely to occur
adjusts to a new equilibrium condition
Denudation
any process that wears away or rearranges landforms (weathering, mass movement, erosion, transportation, deposition)
Dynamic Equilibrium
balancing act between tectonic uplift and reduction by weathering and erosion
Regolith
broken-up rock due to weathering
Vegetation
can protect rock by shielding it from raindrop impact, roots can stabilize soil
Parent Material
consolidated or unconsolidated material from which soils develop, ranging from unconsolidated sediments and weathered rock to bedrock
Slope Orientation
controls slope's exposure to Sun, wind, and precipitation, (facing away from solar radiation are cooler, moister, more vegetated than slopes in direct sunlight... aka don't bake under sunlight (-: )
All processes that cause reduction and rearrangement of landforms are included in the term of a)mass movement b)erosion c)weathering d)denudation
denundation
Delicate Arch in Utah is an example of a)a geological structure created by flowing ice b)a volcanic dome c)differential weathering d)an extinct shield volcano
differential weathering
Mass Movement Types (4)
fall, slide, creep, flow
Joints
fractures or separations in rock that occur without displacement of the sides, increases the surface area of rock exposed to both physical and chemical weathering
On which part of a slope would rocks tend to fall at the highest speed? a)Concave slope b)Convex slope c)Debris slope d)Free face
free face
Scarification
humans cause disturbance of a slope by highway roadcut, surface mining, housing development, forest clear-cut
Erosion
includes weathering & transport of materials to different locations
Endogenic processes build...
initial landscapes
Geomorphic Cycle
1)Equilibrium stability 2)A destabilizing event (i.e., exceed geomorphic threshold) 3)A period of adjustment 4)Development of a new and different condition of equilibrium
5 Factors Influencing Weathering Processes
1.Rock composition and structure (jointing) 2.Climatic conditions 3.Subsurface water 4.Slope orientation 5.Vegetation
Which of the following is true of spheroidal weathering? a)It is a physical weathering process b)It is a type of exfoliation associated with pressure release c)It attacks the corners and edges of rocks d)It is a frost-thaw action
It attacks the corners and edges of rocks
Salt-Crystal Growth (Salt Weathering)
water on the surface of rocks evaporates & dissolved minerals in the water grow crystals, crystals grow and enlarge & exert force to spread apart individual mineral grains and begin breaking up the rock
Sinkholes
weathering of limestone landscapes creates sinkholes, form in circular depressions and caverns
The dynamic equilibrium model refers to a)a balancing act between tectonic uplift and rates of denudation by weathering and erosion in a given landscape b)a theory involving the cyclic or evolutionary development of a landscape c)a sequential development of landforms d)an important concept first stated by Alfred Wegener
a balancing act between tectonic uplift and rates of denudation by weathering and erosion in a given landscape
Chemical Weathering Processes
act on joints in granite to dissolve weaker minerals