Test 3 Flashcards
(43 cards)
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)
