Geology Weeks 1 - 4 Combined
When was Crater Lake established as a national park? (Crater Lake NP)
1902
In which state is the park located? What is the geographic region? (Yellowstone NP)
Regions extend from the northwest corner of Wyoming to (small parts located in Idaho & Montanna). Main geological feature is the huge volcanic caldera within the park.
What is the process of subduction?
Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced down into the mantle.
What is the tectonic situation that produced this volcanic area? (Crater Lake NP)
Subduction of the Juan de Fuca plate under the North-American plate.
What is the zone of saturation? What is the unsaturated zone?
The saturated zone is where water can be found within the pore spaces of the material at depth. The earth materials above the water table without water in its pore spaces is called the unsaturated zone.
What is permeability?
The state or quality of a material to allow liquids or gases to pass through it.
What is the water table? Where do you see it in a river valley?
The top of the saturated zone. The top of the water table is also the water level
How does a geyser work?
The water at the bottom of the geyser's plumbing is under incredible pressure from the water above it. (like a giant pressure cooker)
What is an aquifer? What kind of rocks makes a good aquifer?
The water-bearing unit in the subsurface which contains water in its pore spaces. Sandstone and gravel because they have high porosity and permeability.
Most beach sands are actually tiny pieces of the mineral _____________ .
Quartz
Sandstone is usually comprised of small grains of the mineral _____________ . Hint: See the previous question.
Quartz/Feldspar
Hot Springs
a spring of naturally hot water, typically heated by subterranean volcanic activity.
What type of thermal feature is represented by Mammoth? How does it form? What is the name of the its main rock deposit and what kind of rock is it? (Yellowstone NP)
-Hot springs. Hot groundwater flowing through limestone will dissolve it and bring it to the surface where the limestone minerals, mostly calcite, will precipitate out into travertine or tufa deposits. Limestone.
What are the types of igneous rocks exposed in the park? (Yellowstone NP)
-Ryholite (granitic lava), cemented ash (Weld tuff), Obsidian, and basalt.
What is the name of the main river flowing through the national park? (Yellowstone NP)
-The Yellowstone River
Why is the park called "Yellowstone"? (Yellowstone NP)
-Yellow color of the ryholite flows
What is the name of the lake in the park? What thermal feature can be found in it? (Yellowstone NP)
-Yellowstone Lake. Geysers
How hot is the water that comes out of the 47 springs at the park? (Hot Springs NP)
143 degrees Fahrenheit
What year was the park established? (Yellowstone NP)
1872
In what year was Lassen Volcanic National Park established and in what state is it located? (Lassen Volcanic NP)
1916, California
When was the last volcanic activity at the park? (Lassen Volcanic NP)
1917 eruption
What year was this national park established? (Hot Springs NP)
1921
What fraction of the total number of geysers on Earth is found at Yellowstone? (Yellowstone NP)
20% of the worlds geysers are found at Yellowstone.
Approximately how many tectonic plates are there on Earth?
35
What is carbonic acid?
A chemical compound with the chemical formula H₂CO₃. It is also a name sometimes given to solutions of carbon dioxide in water.
Volcanic Neck
A column of igneous rock formed by congelation of lava in the conduit of a volcano and later exposed by the removal of surrounding rocks.
What is an artesian well? Name the two conditions necessary for forming it.
A confined aquifer containing groundwater under positive pressure. Drilling and groundwater under positive pressure.
What kind of plate boundary is represented in this park? (Lassen Volcanic NP)
A continental-oceanic plate boundary.
What is the difference between a gaining stream and a losing stream?
A gaining stream is one in which the channel bottom is lower than the level of the surrounding groundwater table. Through the course of the summer, water moves from the ground into the channel. A losing stream is one which is above the groundwater table, and water moves from the channel into the surrounding ground.
What kind of tectonic feature is Yellowstone National Park? What kind of volcano is it? (Yellowstone NP)
A hot spot due to the collapse of a "Supervolcano"
What is karst topography? What is a sinkhole or sink?
A landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer.
Lava Tubes/Lava Tunnels
A lava tube is a natural conduit formed by flowing lava which moves beneath the hardened surface of a lava flow.
Magma Chamber
A magma chamber is a large underground pool of liquid rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma.
What kind of plate boundary occurs at the bottom of oceans? What are mid-oceanic ridges?
A mid-ocean ridge demarcates the boundary between two tectonic plates, and consequently is termed a divergent plate boundary. A mid-ocean ridge is an underwater mountain system formed by plate tectonics.
Mid-Oceanic Ridge
A mid-ocean ridge is an underwater mountain system formed by plate tectonics.
Rift valley
A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading apart of the surface, which is subsequently further deepened by the forces of erosion.
What is an aquiclude or aquitard? What kind of material makes aquicludes or aquitards?
Any geological formation that absorbs and holds water but does not transmit it at a sufficient rate. Shales and clays.
In what type of "spaces" under the surface does groundwater collect and move?
Aquifer
In what state is Hot Springs National Park located? (Hot Springs NP)
Arkansas
Why is the spring water hot here? (Hot Springs NP)
As the water goes deep into the earth, it becomes heated by the natural heat gradient of the earth and compression.
Ash/Cinders/Bombs
Ash, cinders and bombs are only produced in explosive eruptions because during an explosive eruption, thick, sticky lava clogs the volcano's pipe. When the dissolved gases build up pressure, the volcano explodes, throwing out chunks of lava which then cool and harden into ash, cinders or bombs.
Generally how deep is the lake anyway? Why do you think it did not have any fish last century? (Crater Lake NP)
At the max, 1,949 ft. There were no native fish. The two species that do live here were introduced by humans within the last century.
What black igneous rock is extremely common and sometimes cools to become tall, thin columns?
Basalt
What kind of rocks make up the ocean crust?
Basalt
What kinds of rocks are exposed in the Crater Lake area? (Crater Lake NP)
Basalt, Andesite, and Dacite
What mineral primarily makes up limestone and travertine? (FYI: Travertine is common around hot springs.)
Calcite
The lake is situated in what kind of volcanic structure? (Crater Lake NP)
Caldera
What kind of rock is dissolved by rainwater to make solution caves?
Carbonate and sulfate rocks such as limestone, dolomite, marble, and gypsum.
Name a mountain chain (continental volcanic arc) produced by subduction.
Cascade Mountains
What kind of volcanic structure is Wizard Island? (Crater Lake NP)
Cinder Cone
Shales are primarily made of minerals called _______________ .
Clay + quartz/calcite = mud
Can you guess whether the waters at the bottom are hot or cold? (Crater Lake NP)
Cold
At what kind of plate boundary does ocean crust melt to make volcanoes?
Convergent
What kind of plate boundary is present along the Cascades Mountains of the US Northwest?
Convergent
What kind of plate boundary occurs along the Alaskan Aleutian Islands?
Convergent
What kind of plate boundary occurs when continents collide? Are there volcanoes?
Convergent - creates mountains and often volcanoes.
What is the difference between convergent and divergent plate boundaries?
Convergent boundaries push towards each other, while divergent boundaries are moving away from each other
Of what do you think the layers seen in the rock walls around Crater Lake are composed? (Crater Lake NP)
Dacite
What is the hardest mineral?
Diamond
What kind of plate boundary occurs in East Africa?
Divergent
At what kind of plate boundary is Iceland located? What kind of igneous rocks are produced there? Is Iceland growing or shrinking?
Divergent. Basalt. Growing.
Why do hot springs exist?
Due to the emergence of geothermally heated groundwater that rises from the Earth's crust.
How often does Old Faithful erupt? (Yellowstone NP)
From 45-90 minutes
What are the five types of thermal features in the park? What is the estimated number of thermal features in the park? (Yellowstone NP)
Geysers, hot springs, mud pots, fumaroles, and steam vents. 10,000!
What kind of rocks make up the continental crust?
Granite
Is there more groundwater or surface water on the continents?
Groundwater
Name a mountain chain produced by the collision of continents.
Himalayas
Hawaii is not on a plate boundary. Why does it have volcanoes?
Hot spots
Black Smokers
Hydrothermal vents that may form features near tectonic plates, basins, and hotspots
Why do the hot springs flow upward here in the park? Is it hydrostatic pressure or gravity that controls their flow? (Hot Springs NP)
Hyrdrostatic Pressure which is caused by gravity
How do igneous rocks form?
Igneous rocks are crytallized from liquid rock
What are the four major layers of the Earth?
Inner Core, Outer Core, Mantle, and Crust
What are other kinds of caves or caverns?
Lava, glacier, sea.
Name an island chain (volcanic island arc) produced by subduction.
Luzon Volcanic Arc
What is present under the park to produce these volcanic features? (Lassen Volcanic NP)
Magma chamber & hot rock
Magma and lava are both molten rock, so why do they have different names?
Magma is underground and is called lava when it comes up to the surface
Describe the composition of the ocean crust layers.
Magma rises and creates at a linear weakness in the oceanic crust, and emerges as lava, creating new crust upon cooling.
How do metamorphic rocks form?
Metamorphic rocks form when sedimentary and igneous rocks are heated and metamorphose into new types of rocks.
What was the name of the original volcano at this site? (Crater Lake NP)
Mt Mazama
What is the name of the original volcano that stood in the park? (Lassen Volcanic NP)
Mt. Tehama
What other four features are similar to those of Yellowstone National Park? (Lassen Volcanic NP)
Mud pots, steam vents, hot springs, and fumaroles
The three metamorphic rocks shown in the Powerpoint slides are: Marble, slate, and gneiss. According to the slides, minerals must meet four criteria. Those four are:
Must be solid, have a definite chemical formula, is not organic, and must be naturally occuring
What are the three most common minerals in granite?
Obsidian, Pumice, and porphyry
Volcanic Island Arc
Offshore volcanoes form islands, resulting in a volcanic island arc.
Which layer of the Earth is molten (liquid)?
Outer core
For whom was Mt. Lassen named? (Lassen Volcanic NP)
Peter Lassen, an early California pioneer
Gabbro and basalt are closely related igneous rocks. Granite and ____________ are closely related igneous rocks. Hint: The lava that belongs in the blank is often pink.
Ryholite
What is the type of rock that makes up the aquifer that is the source of the hot springs at the park? (Hot Springs NP)
Sandstone
The four sedimentary rocks shown in the Powerpoint slides are:
Sandstone, siltstones, shales, and limestones
What is sea floor spreading? How do ocean basins form?
Sea floor spreading occurs at divergent plate boundaries through volcanic activity. Ocean basins form as a result of thise
Pahoehoe/Aa Lavas
Slow-flowing lava/Rapidly flowing lava
What is porosity?
The ability of space to hold water and maintaining good permeability
How was Crater Lake formed? (Crater Lake NP)
The eruption of Mazama, which resulted in a collapse and creation of the caldera
Why does Yellowstone have so many thermal features, i.e. what is the source for all the heat? (Yellowstone NP)
The heat that drives geothermal activity in the Yellowstone area comes from brine (salty water) that is 1.5 to 3 miles (2.4 to 4.8 km) below the surface.[3] This is actually below the solid volcanic rock and sediment that extends to a depth of 3,000 to 6,000 feet (900 to 1,800 m) and is inside the hot but mostly solid part of the pluton that contains Yellowstone's magma chamber.
How did the magnetic field of the Earth help scientist understand plate motion?
The magnetic patterns were similar/mirror images on either side of the mid-oceanic ridge, which implies that either side of the ridge is moving away from each other.
How do sedimentary rocks form?
These form from the disinegration of rocks and the accumulation of their pieces
What kind of plate boundary is present in California?
Transform boundary
Lower Yellowstone Falls is how many times higher than the falls at Niagara? Where exactly is the location of the Upper and Lower Yellowstone Falls? (Yellowstone NP)
Twice as high....As the Yellowstone river flows north from Yellowstone Lake, it leaves the Hayden Valley and plunges first over Upper Yellowstone Falls and then a quarter mile (400 m) downstream over Lower Yellowstone Falls.
Do all plate boundaries experience earthquakes?
Unless they are stationary, yes, but divvergent boundaries are not very powerful.
Are the rock strata in the area horizontal or more vertical? What is the general name of the geologic structure that makes the rock strata that way? (Hot Springs NP)
Vertical, the structure is called a fault
What kind of volcanic feature is Mt. Lassen? (Lassen Volcanic NP)
Volcanic dome associated with Mt. Tehama's caldera
What is the ultimate source of the water in the hot springs in the Hot Springs NP?
Water that falls as rain
How do springs form? What is a perched water table?
Where groundwater intersects with the ground surface and flows out onto the surface. An accumulation of groundwater that is above the water table in the unsaturated zone.
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Shield Volcano
a broad, domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava
Cinder Cone
a cone formed around a volcanic vent by fragments of lava thrown out during eruptions.
Stratovolcano or Composite Volcano
a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic explosive eruptions and effusive eruptions, although some have collapsed craters called calderas.
Pyroclastic Flows
a fast-moving current of hot gas and rock
Geysers
a hot spring in which water intermittently boils, sending a tall column of water and steam into the air.
Caldera
a large volcanic crater, typically one formed by a major eruption leading to the collapse of the mouth of the volcano
Volcanic Fissures
a linear volcanic vent through which lava erupts, usually without any explosive activity
Lava Flows
a mass of flowing or solidified lava
Stalagmites
a mound or tapering column rising from the floor of a cave, formed of calcium salts deposited by dripping water and often uniting with a stalactite.
Laccoliths
a sheet intrusion (or concordant pluton) that has been injected between two layers of sedimentary rock.
Stalactites
a tapering structure hanging like an icicle from the roof of a cave, formed of calcium salts deposited by dripping water.
What is a transform plate boundary?
a type of fault whose relative motion is predominantly horizontal
Lahars
a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water.
Batholiths
a very large igneous intrusion extending deep in the earth's crust.
Hot Spot
an area in the mantle from which heat rises as a thermal plume from deep in the Earth.
Nueé Ardente
an incandescent cloud of gas, ash, and lava fragments ejected from a volcano, typically as part of a pyroclastic flow.
Vent (Neck)/Pipe
an opening exposed on the earth's surface where volcanic material is emitted.
Fumaroles
an opening in the crust, often in areas surrounding volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide.
Plutons
body of intrusive igneous rock (called a plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, stocks, dikes, sills, laccoliths, and other igneous bodies.
Continental Volcanic Arc
chain of volcanoes formed above a sub-ducting plate, positioned in an arc shape as seen from above.
Speleothem
commonly known as a cave formation, is a secondary mineral deposit formed in a cave. Speleothems typically form in limestone solution caves.
List the five igneous volcanic features found in the park. (Lassen Volcanic NP)
dacite flows (Mt. Lassen), older andesite flows weathered to clays, pyroclastics, cinder cones with basaltic lava, and andesitic shield-like volcanoes
Lava Lakes
large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression.
Lava Dome
lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano.
Pillow Lava
lava that has solidified as rounded masses, characteristic of eruption under water.
Dikes/Sills
sheet of rock that formed in a fracture in a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorphic rock.