Test 3 Flashcards
what is the law of superposition?
rock and sediment are always arranged with the youngest bed towards the top of a rock formation and the oldest at the base, if they have not been disturbed
what is an exogenic system?
external processes that set into motion air, water, and ice, all powered by solar energy
what is an endogenic system?
internal processes that produce flows of heat and material from deep below earth’s crust
what is earth’s structure? (inner to outer)
core (inner, outer), mantle (lower, upper), lithosphere, crust
what is isostatic adjustment?
the state of gravitational equilibrium between the lithosphere and asthenosphere, causing tectonic plates to float at an elevation depending on their thickness and density
what are two igneous rocks?
intrusive (formed below earth’s surface) and extrusive (formed at surface)
how do sedimentary rocks form? (4)
weathering and erosion of existing rocks, accumulation of shells, accumulation of organic matter, and precipitation of minerals from water
what is a metamorphic rock and what causes it?
when an igneous or sedimentary rock undergoes changes, caused by heating, pressure, heating AND pressure, or compression
what is a divergent plate boundary?
when plates move apart and magma upwells, forming a new crust
what is a transform plate boundary?
regions of crustal collision and subduction (when one plate goes underneath another, diving into the mantle)
what is a convergent plate boundary?
when two plates of similar density collide the high pressure causes uplift of the crust producing mountains
what is a hot spot?
large regions of hot mantle just below the surface
what are the two different types of eruptions?
effusive (low viscosity, not must gas or ash) and explosive (high viscosity, lots of ash and gas)
what are hazards of volcanoes? (6)
pyroclastic flows, lava flows, gas, ash, jökulhaups, and lahars
What are the different types of volcanoes? (3)
Shield volcanoes (more wide than tall, effusive), composite volcanoes (stratovolcanoes - explosive, tall and steep, near zones of subduction), and fissure volcanoes (no central chamber or pipe, magma comes from large cracks in ground)
what are the two types of weathering?
physical and chemical
what are different examples of physical weathering? (4)
frost (water freezes and cracks rocks), salt (evaporates from sandstone pores, leaves salt crystals), pressure-release (when pressure is removes, rock expands), and plants (put pressure on rocks when growing)
what are different examples of chemical weathering? (3)
oxidation (when an element combines with oxygen ion), hydrolysis (when chemical compounds are decomposed due to reaction with water), and carbonate dissolution (carbonation - when a mineral dissolves into solution)
what is karst topography?
a limestone regions with a specific landscape of pitted, bumpy surface topography and poor drainage due to chemical weathering
what factors influence weathering? (6)
rock composition and structure (bedrock), climate (precipitation, temperature, and freeze-thaw cycles), slope orientation (controls exposure to sun, wind, and precipitation), vegetation (can protect rock and break up rock), time (all these processes take time), and joints (fractures in rocks, increase physical and chemical weathering)
what is angle of repose?
a balance of driving and resisting forces, the steepest angle that material can be piled up, courser particles have greater angle of repose
what are classes of mass movement? (4)
fall, slide, flow, and creep
initiation of rivers (5)
sheet flow (thin film over surface), rills (small grooves caused by water), gullies (larger rills), streams (water flow in valley floors), and rivers (large system fed by many streams)
4 different types of erosion
hydraulic action (force of river makes air get trapped in cracks weakening bank and wearing it away), abrasion (rocks wearing down river bed), attrition (rocks smash together in river and break into smaller pieces), and corrosion/solution (rocks dissolved by acid in water and carried downstream)
3 main ways sediment is moved in stream
bed load (coarser), suspended load (finer), dissolved load (solution load)
how do river meanders form?
Rivers form meanders by eroding the outer bends and depositing sediment on the inner bends, creating curved patterns.
two different landforms associated with fluvial processes?
erosional (shaped by progressive removal of materials) and depositional (surface features created by transportation and deposition of materials
two types of aeolian erosion?
deflation (removing and lifting individual loose particles) and abrasion (grinding rock surface by sandblasting particles captured in air)
what is are 5 types of dunes?
barchan, transverse, start, parabolic, and longitudinal (linear)
how do sand dunes form?
sand grains drift along by saltation, sand grains pile up, more pile up, creating dune
how are glaciers formed?
snow accumulates and survives through summer, old snow is pressured and recrystallized the next winter, after many years this creates dense glacial ice
what is positive and negative mass balance for glaciers?
positive - cold periods with lots of snow, negative - warm periods with lots of melt
different ways to add mass to glaciers (accumulation) (3)
snow, avalanching, and basal ice (water freezing onto bed)
different to remove mass from glaciers (ablation) (3)
melting, calving (blocks of ice breaking off into water - makes icebergs) and sublimation (water going to gas directly)
how do glaciers move? (2)
basal slip and internal deformation
deposition by glaciers (2)
stratified drift (deposited by meltwater streams or in bodies of water) and till (deposited directly from ice without water transport)
landforms made by ice sheets (6)
moraines, kettle, drumlin, esker, kame, and outwash plain
what is a moraine?
deposits of glacial till, material let behind by a glacier
what is a kettle?
steep-sided, basin, or bowl-shaped depressions
what is a drumlin?
low, smoothly rounded, elongate, or oval hill
what is an esker?
long, narrow, sinuous ridge of glacial till?
what is a kame?
low mounds or knobs of till
what is an outwash plain?
broad, gently sloping plain where meltwater deposits sediment
