Geo Exam 2
Silica, Calcite, and Iron Oxide
What are the three most common cementing agents for sandstones?
What is the most common chemical sedimentary rock?
very fine-grained volcanic ash deposited in an ancient lake
Which of the following would retain the most detailed impressions of fossilzed organisms?
Sedimentary rocks account for about what percentage of the Earth's outermost 10km of rock?
Imagine a mountain stream whose fast-moving water has carried away all grains except for well-rounded pebbles, cobbles, and boulders. If such stream gravel were lithified, it would turn into
Evaporites are a type of BLANK sedimentary rock, examples are
Which of the following forms at the highest grade of regional metamorphism?
calcite grains grow larger and form interlocking crystals
What major change occurs during metamorphism of limestone to marble?
Which low-grade metamorphic rock, composed of very fine-grained minerals, is dull, and is fissile?
Which rock is thought to form by the partial melting and crystallization of the melted portion within the rock?
high temperatures associated with meteorite impacts
Tektites originate in what metamorphic environment?
Which of the following rocks is a nonfoliated rock formed by contact metamoprhism of shale or mudstone?
at great depths in the crust where two continents are colliding, forming mountains
In which setting would regional metamorphism be most likely?
Which of the following mass wasting events moves the fastest and most destructive?
prolonged and intense rainfall
What was the main factor for the landslide at la conchita, Ca in 2005?
by type of material, velocity and type of motion
In general, how are mass wasting processes classified?
The soil expands and contracts, lifiting particles and dropping them at a slight distance downslope
How do freeze- thaw or wet- dry cycles contribute to soil creep?
Which river has the largest discharge of any river in the world?
The natural channel had a lower gradient and higher friction than the straight channel
A natural, meandering river channel is modified into a more or less straight and smooth, canal-like channel.
The channel width times the channel depth times the velocity
What is the correct definiton of stream discharge?
Silt and clay-sized particles
What make up the suspended laods of most rivers and streams?
infiltration decreases; runoff increases
How does urbanization affect infiltration and runoff and infiltration in a small, previously forested, drainage basin?
a BLANK stream pattern developes on lands underlain by tilted or folded, alternating hard and soft sedimentary strata
v-shaped cross-valley profiles
BLANK are characteristics of downcutting streams and youthful stage of valley evolution
Evaporation and transpiration
What are the components of the hydrologic cycle that release water vapor directly to the atmosphere?
on the outer parts of the meander loops, cut bank
Where is erosion concentrated along a meandering stream?
it increases in maximum diameter nine times
If the velocity of a stream triples, how does this affect its competence?
Zone of soil moisture
What is the term for the zone where water is held by molecular attraction to soil particles?
the surface is irregular and is influenced by rainfall variation
What is true about the surface of the water table?
It can happen because interaction between groundwater and streams can change due to different factors
Is it possible that a single stream may be gaining in some areas and losing in others?