Geology Flashcards
Exam #2
1
Q
Viscous
A
Explosive
2
Q
Non-Viscous
A
Non-Explosive
3
Q
Viscosity
A
A magma’s resistance to flow and depends on temp. and comp.
4
Q
High SiO2 =
A
More Viscous(explosive) and magma solidifies at lower temps. making them even more viscous.
5
Q
When magma rises to the earths surface it is called…?
A
Lava.
6
Q
Mafic Magma silica content(%), viscosity, Eruption temps. (*C) and Eruption Style:
A
45-52% Silica
Low Viscosity
Up to 1300 *C
Flows
7
Q
Intermediate Magma silica content(%), viscosity, Eruption temps. (*C) and Eruption Style:
A
53-65% Silica
Intermediate Viscosity
About 1000 *C
Flows and explosions.
8
Q
Felsic Magma silica content(%), viscosity, Eruption temps. (*C) and Eruption Style:
A
> 65% Silica
High Viscosity
Less than 900 *C
Domes and explosions.
9
Q
Shield Volcanoes
A
Are wide and gently sloping.
10
Q
Fissures
A
A fissure vent, also known as a volcanic fissure or eruption fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity. The vent is often a few metres wide and may be many kilometres long.
11
Q
Flood basalt
A
A “flood basalt” is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava
12
Q
Lava Tubes
A
a natural tunnel within a solidified lava flow, formerly occupied by flowing molten lava.
13
Q
Cinder Cones
A
A cinder cone or scoria cone is a steep conical hill of loose pyroclastic fragments, such as either volcanic clinkers, cinders, volcanic ash, or scoria that has been built around a volcanic vent.
14
Q
Scoria
A
a cindery, vesicular basaltic lava, typically having a frothy texture.
15
Q
Pyroclastic flow
A
A pyroclastic flow is a fast-moving current of hot gas and volcanic matter that moves away from a volcano about 100 km/h on average but is capable of reaching speeds up to 700 km/h.
16
Q
Stratovolcanoes
A
A stratovolcano is a tall, conical volcano composed of one layer of hardened lava, tephra, and volcanic ash. These volcanoes are characterized by a steep profile and periodic, explosive eruptions. The lava that flows from them is highly viscous, and cools and hardens before spreading very far.
17
Q
Tephra
A
rock fragments and particles ejected by a volcanic eruption.
18
Q
Pumice
A
Glassy solidified magma that contains abundant gas bubbles
19
Q
Ash
A
small crystals, rock fragments, and bits of glassy frozen magma
20
Q
Dome
A
a lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano.
21
Q
Magma chamber
A
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is under great pressure, and, given enough time, that pressure can gradually fracture the rock around it, creating a way for the magma to move upward.
22
Q
Tuff
A
Volcanic ash that becomes lithified.
23
Q
Lithification
A
the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithification is a process of porosity destruction through compaction and cementation.
24
Q
Caldera
A
A caldera is a large cauldron-like hollow that forms following the evacuation of a magma chamber/reservoir. When large volumes of magma are erupted over a short time, structural support for the crust above the magma chamber is lost.
25
Hotspot
A volcanic "hotspot" is an area in the mantle from which heat rises as a thermal plume from deep in the Earth. High heat and lower pressure at the base of the lithosphere (tectonic plate) facilitates melting of the rock. This melt, called magma, rises through cracks and erupts to form volcanoes.
26
Lahar
A lahar is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley.
27
Aa flows
A'a is characterized by a rough, jagged, spinose, and generally clinkery surface. Aa lava flows tend to be relatively thick compared to pahoehoe flows. During the early episodes of the current eruption of Kilauea volcano, aa flows up to 36 feet (11 m) thick surged through the Royal Gardens subdivision at rates as great as 108 ft/min (33 m/min).
28
Pahoehoe
Pahoehoe is the second most abundant type of lava flow.
Pahoehoe lava is characterized by a smooth, billowy, or ropy surface.
Pahoehoe flows tend to be relatively thin, from a few inches to a few feet thick. In map-view the flows tend to be narrow and elongate.
29
Pillow lava
Pillow lavas are volumetrically the most abundant type because they are erupted at mid-ocean ridges and because they make up the submarine portion of seamounts and large intraplate volcanoes, like the Hawaii-Emperor seamount chain.
Eruptions under water or ice make pillow lava.
30
Alluvial Fan
a fan-shaped mass of alluvium deposited as the flow of a river decreases in velocity.
31
braided channel
A braided river, or braided channel, consists of a network of river channels separated by small, and often temporary, islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with low slope and/or large sediment load.
32
Cut Bank
Cut banks are found in abundance along mature or meandering streams, they are located on the outside of a stream bend, known as a meander, opposite the slip-off slope on the inside of the bend. They are shaped much like a small cliff, and are formed by the erosion of soil as the stream collides with the river bank.
33
Capacity
The capacity of a stream or river is the total amount of sediment a stream is able to transport. ... Stream capacity is often mistaken for the stream competency, which is a measure of the maximum size of the particles that the stream can transport, or for the total load, which is the load that a stream carries.
34
Channel
a channel is a type of landform consisting of the outline of a path of relatively shallow and narrow body of fluid, most commonly the confine of a river, river delta or strait.
35
Delta
A delta is a fan of braided streams and sediment formed when a river discharges into a larger body of water: a sea or a lake. It will be useful if the reader has already read the article on rivers before reading further.
36
Discharge
In hydrology, discharge is the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids (e.g. sediment), dissolved chemicals (e.g. CaCO3(aq)), or biologic material (e.g. diatoms) in addition to the water itself.
37
Divide
Divide. A ridge or other topographic feature that separates two adjacent drainage basins. It is an imaginary line that separates two different directions of surface water flow.
38
flash flood
A flash flood is a rapid flooding of geomorphic low-lying areas: washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, tropical storm, or meltwater from ice or snow flowing over ice sheets or snowfields. Flash floods may occur after the collapse of a natural ice or debris dam, or a human structure such as a man-made dam
39
Flood crest
it is the highest stage or level of a flood wave as it passes a particular point.
40
Flood frequency curve
A flood frequency curve is a valuable tool to extrapolate how often a flood of a given discharge will occur. A flood frequency curve can be constructed by plotting a graph of discharge versus recurrence interval.
41
Floodplain
Floodplain, also called Alluvial Plain, flat land area adjacent to a stream, composed of unconsolidated sedimentary deposits (alluvium) and subject to periodic inundation by the stream.
42
gradient
Stream gradient is the grade measured by the ratio of drop in elevation of a stream per unit horizontal distance, usually expressed as metres per kilometre or feet per mile.
43
Hydrograph
A hydrograph may be used to show how the water flow in a drainage basin (particularly river runoff) responds to a period of rain. This type of hydrograph is known as a storm or flood hydrograph and it is generally drawn with two vertical axes.
44
Levee
levee. [lĕv′ē] A long ridge of sand, silt, and clay built up by a river along its banks, especially during floods. An artificial embankment along a rivercourse or an arm of the sea, built to protect adjoining land from inundation.
45
Load
Stream load is a geologic term referring to the solid matter carried by a stream (Strahler and Strahler, 2006). Erosion and bed shear stress continually remove mineral material from the bed and banks of the stream channel, adding this material to the regular flow of water.
46
Longitudinal profile
A typical longitudinal profile is curved, with a steep slope near the headwaters, and a gentle slope near the mouth. - That means that the stream gradient (average slope of the stream) is greater near the headwaters and less near the mouth.
47
meander
A meander is one of a series of regular sinuous curves, bends, loops, turns, or windings in the channel of a river, stream, or other watercourse. It is produced by a stream or river swinging from side to side as it flows across its floodplain or shifts its channel within a valley.
48
mouth
The place where a river meets the ocean is the mouth of the river. The river mouth is where much of this gravel, sand, silt, and clay—called alluvium—is deposited. When large amounts of alluvium are deposited at the mouth of a river, a delta is formed. The river slows down at the mouth, so it doesn't have the energy to carry all the silt, sand, and clay anymore.
49
oxbow lake
An oxbow lake forms when a river creates a meander, due to the river's eroding the bank. After a long period of time, the meander becomes very curved, and eventually the neck of the meander becomes narrower and the river cuts through the neck during a flood, cutting off the meander and forming an oxbow lake.
50
permeability
Permeability is the property of rocks that is an indication of the ability for fluids (gas or liquid) to flow through rocks. High permeability will allow fluids to move rapidly through rocks. Permeability is affected by the pressure in a rock.
51
recurrence interval
A return period, also known as a recurrence interval (sometimes repeat interval) is an estimate of the likelihood of an event, such as an earthquake, flood, landslide, or a river discharge flow to occur.
52
runoff
Runoff can be described as the part of the water cycle that flows over land as surface water instead of being absorbed into groundwater or evaporating. Runoff is that part of the precipitation, snow melt, or irrigation water that appears in uncontrolled surface streams, rivers, drains, or sewers.
53
stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.
54
tributary
A tributary is a freshwater stream that feeds into a larger stream or river. The larger, or parent, river is called the mainstem. The point where a tributary meets the mainstem is called the confluence. Tributaries, also called affluents, do not flow directly into the ocean.
55
trunk river
The drainage basin is the fundamental landscape unit in a fluvial processes. This is a system of a primary, or trunk, river and its tributaries. These watersheds are separated from their neighbors by a divide; a highpoint where water flows in different directions on either side.
56
watershed
an area or ridge of land that separates waters flowing to different rivers, basins, or seas.
57
wetland
A wetland is a distinct ecosystem that is inundated by water, either permanently or seasonally, where oxygen-free processes prevail. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil.
58
angle of repose
the steepest angle at which a sloping surface formed of a particular loose material is stable.
59
cohesion
Cohesion is the component of shear strength of a rock or soil that is independent of interparticle friction. In soils, true cohesion is caused by following: Electrostatic forces in stiff overconsolidated clays (which may be lost through weathering)
60
creep
Creep, in geology, slow downslope movement of particles that occurs on every slope covered with loose, weathered material. Even soil covered with close-knit sod creeps downslope, as indicated by slow but persistent tilting of trees, poles, gravestones, and other objects set into the ground on hillsides.
61
debris flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors.
62
driving force
For much of the last quarter century, the leading theory of the driving force behind tectonic plate motions envisaged large scale convection currents in the upper mantle which are transmitted through the asthenosphere.
63
earthflow
An earthflow (earth flow) is a downslope viscous flow of fine-grained materials that have been saturated with water and moves under the pull of gravity. It is an intermediate type of mass wasting that is between downhill creep and mudflow.
64
fall
Falls are landslides that involve the collapse of material from a cliff or steep slope. Falls usually involve a mixture of free fall through the air, bouncing or rolling. A fall type landslide results in the collection of rock or debris near the base of a slope.
65
flow
Flows are landslides that involve the movement of material down a slope in the form of a fluid. When material on a slope becomes saturated with water, making it much heavier, it may develop into a debris flow or mud flow.
66
friction
Fault lubrication (during faulting) ... Fault lubrication then is the phenomena whereby the friction on the fault surface decreases as it slips, making it easier for the fault to slip as it does so. One method by which this occurs is through frictional melting.
67
karst terrain
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions.
68
landslide
A landslide, also known as a landslip, is a geological phenomenon that includes a wide range of ground movements, such as rockfalls, deep failure of slopes and shallow debris flows. Landslides can occur in offshore, coastal and onshore environments.
69
mass movement
Alternative Title: mass wasting. Mass movement, also called Mass Wasting, bulk movements of soil and rock debris down slopes in response to the pull of gravity, or the rapid or gradual sinking of the Earth's ground surface in a predominantly vertical direction.
70
pore pressure
The pressure of fluids within the pores of a reservoir, usually hydrostatic pressure, or the pressure exerted by a column of water from the formation's depth to sea level.
71
quick clay
Quick clay and quick clay landslides. Quick clay* is clay with 'quick' properties. ... Quick clay (and other types of sensitive clay) is formed in Norway in areas where clay was deposited in a saline marine environment, and subsequently lifted near or above sea level due to post-glacial uplift.
72
regional subsidence
Subsidence is either the sudden sinking or gradual downward settling of the ground's surface with little or no horizontal motion. ... Ground subsidence is of concern to geologists, geotechnical engineers, surveyors, engineers, urban planners, landowners, and the public in general. Subsidence is a global problem.
73
resisting force
Resisting forces act oppositely of driving forces. The resistance to downslope movement is dependent on the shear strength of the slope material. And shear strength is a function of cohesion (ability of particles to attract and hold each other together) and internal friction (friction between grains within a material).
74
rotational slide
A slide type landslide is a down-slope movement of material that occurs along a distinctive surface. If this slip surface is curved the slide said to be rotational. The slip surface of a rotational landslide tends to be deep. ... The rotated blocks can be seen as grass covered 'benches' in the photograph.
75
sinkhole
Sinkhole, also called sink or doline, topographic depression formed when underlying limestone bedrock is dissolved by groundwater. It is considered the most-fundamental structure of karst topography. Sinkholes vary greatly in area and depth and may be very large.
76
slide
A slide-type landslide is a down-slope movement of material that occurs along a distinctive surface of weakness such as a fault, joint or bedding plane. If the slip surface is straight then it is termed translational or planar.
77
slope failure
Slope angle, climate, slope material, and water contribute to the effect of gravity. Mass movement occurs much more frequently on steep slopes than on shallow slopes. Water plays a key role in producing slope failure. ... The weight (load) on the slope increases when water fills previously empty pore spaces and fractures.
78
slump
A slump is a form of mass wasting that occurs when a coherent mass of loosely consolidated materials or rock layers moves a short distance down a slope. Movement is characterized by sliding along a concave-upward or planar surface.
79
talus
Geologists define talus as the pile of rocks that accumulates at the base of a cliff, chute, or slope. The formation of a talus slope results from the talus accumulation.
80
translational slide
A slide-type landslide is a down-slope movement of material that occurs along a distinctive surface of weakness such as a fault, joint or bedding plane. If the slip surface is straight then it is termed translational or planar.
81
unconsolidated material
Unconsolidated sediments are loose materials, ranging from clay to sand to gravel
82
barrier island
A barrier island is a long, thin, sandy stretch of land, oriented parallel to the mainland coast that protects the coast from the full force of powerful storm waves. Between the barrier island and the mainland is a calm, protected water body such as a lagoon or bay.
83
beach
A beach forms when waves deposit sand and gravel along the shoreline. Some beaches are made of rocks and pebbles. Over time they are worn smooth from being rolled around by waves. The rocks usually reflect the local geology.
84
beach drift
The swash zone is the area at the water's edge where waves lap up onto the beach, and the term swash is used to describe the water that moves onshore from the waves. ... This creates the zigzagged pattern of beach drift, or longshore drift, which is the progressive movement of sand and sediment along the beach.
85
beach face
It usually consists of loose particles, which are often composed of rock, such as sand, gravel, shingle, pebbles, or cobblestones. ... small systems where rock material moves onshore, offshore, or alongshore by the forces of waves and currents; or. geological units of considerable size.
86
beach nourishment
Beach nourishment (also referred to as beach renourishment, beach replenishment, or sand replenishment) describes a process by which sediment, usually sand, lost through longshore drift or erosion is replaced from other sources.
87
berm
A nearly horizontal plateau on the beach face or backshore, formed by the deposition of beach material by wave action, or by means of a mechanical plant as part of a beach recharge scheme
88
breakwater
A breakwater is a large pile of rocks built parallel to the shore. It is designed to block the waves and the surf. Some breakwaters are below the water's surface (a submerged breakwater). Breakwaters are usually built to provide calm waters for harbors and artificial marinas.
89
bulkhead
a structure build to protect from landslides
90
dredging
Removing sediments or other material from one area and depositing them in another area, usually done in a lake or other body of water. For example, harbors and canals are often dredged to removed accumulated sediments so that the water remains deep enough for ships to pass safely.
91
dune restoration
Sand dunes are common features of shoreline and desert environments. ... Stabilizing dunes involves multiple actions. Planting vegetation reduces the impact of wind and water. Wooden sand fences can help retain sand and other material needed for a healthy sand dune ecosystem
92
estuary
Estuaries are typically classified by their existing geology or their geologic origins (in other words, how they were formed). The five major types of estuaries classified by their geology are coastal plain, bar-built, deltas, tectonic and fjords.
93
groin
A groyne is a rigid hydraulic structure built from an ocean shore (in coastal engineering) or from a bank (in rivers) that interrupts water flow and limits the movement of sediment. It is usually made out of wood, concrete or stone.
94
effects of hurricane to coast
beach erosion, dune erosion, inlet formation from flood and ebb surge, landscape changes through tree destruction by wind and nearshore channeling and sedimentation resulting from ebb surge.
95
jetty
A jetty is a long, narrow structure that protects a coastline from the currents and tides. Jetties are usually made of wood, earth, stone, or concrete. They stretch from the shore into the water. Currents and tides of an ocean can gradually wash away a beach or other features along the coastline. This is called erosion.
96
longshore current
long-shore current is an ocean current that moves parallel to shore.
97
longshore drift
The transport of sand and pebbles along the coast is called longshore drift. The prevailing wind (the direction the wind ususally blows from) causes waves to approach the coast at an angle. The swash carries the sand and pebbles up the beach at the same angle (usually 45º)
98
revetment
Revetments: wooden, steel, or concrete fence-like structures that allow sea water and sediment to pass through, but the structures absorb wave energy. A beach can build up behind the revetment and provide further protection for the cliff. These are used as part of coastal defences.
99
rip current
A rip is a strong, localized, and narrow current of water which moves directly away from the shore, cutting through the lines of breaking waves like a river running out to sea, and is strongest near the surface of the water.
100
seawall
seawalls are vertical or near vertical shore-parallel structures designed to prevent upland erosion and storm surge flooding.
101
storm surge
Storm surge is a surge of water produced by an approaching storm that is over and above the normally expected water level - including the astronomical tides. Storm surge is often confused with storm tide, which is a water level rise produced by the combined effect of the surge and the astronomical tide.
102
surf zone
The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash.
103
tide
Image result for tide geologygeologycafe.com
Tides are caused by the gravitational pull of the moon and sun on the ocean. Click to view larger and see the legend. The difference between high tide and low tide is called the tidal range. ... Smaller tides, called neap tides, are formed when the earth, sun and moon form a right angle.
