Chapter 9: Endogenic Processes
Cinders
(2-4 mm)
Lapilli
(4-64 mm)
Blocks
(>64mm)
Lava flows; Shield volcanoes; Cinder cones Composite cones; Plug domes; Calderas
6 major kinds of volcanic landforms
Graben
Each block that slid downward between two normal faults, or that remained in place while blocks on either side slid upward along the faults is called _____
Within; originating
Endo:______; genic:_______
Endogenic processes
Geomorphic processes that originate within earth, tend to increase the amount of surface relief
Tekton
Greek: __________ , carpenter, builder
Charles F. Richter (1935)
He developed a numeric scale of earthquake magnitude to express the size of earthquakes
Nevados Ojos del Salado
Highest volcano, an andesitic composite cone that reaches an elevation of 6887 m
European Alps
Highly complex folding created the ________, where folds are overturned, sheared off, and piled on top of one another
Sill
Horizontal sheet of intrusive igneous rock
Mountain ranges; Basins
Horsts form __________ Grabens form _______
Tectonic forces
Move the lithospheric plates, also causd bending, warping, folding and fracturing of Earth's crust at continental, regional and even local scales
Landforming tectonic processes
Movements of parts of the crust and upper mantle, and igneous processes
Appalachian Mountain system
Much of the ______ is an example of folding on a large scale
Laccolith
Mushroom-shaped intrusion that develops where molten magma pushes its way between preexisting horizontal layers of other rock
Millimeters; Centimeters
Natural landforming processes proceed at a wide variety of rates usually expressed in ________ or ________ of change per year, century or millenium
Columnar-jointed basalt flows
Network of vertical fractures that break the rock into numerous hexagonal columns creates ________
Escarpment
Often shortened to scarp, is a steep cliff, which may be tall of short
Landforms
One of the most appealing and impressive elements of Earth's surface
Flowing water; Wind; Moving ice; waves People
The most common geomorphic agents are ____, _____,______ and _____ but organisms including ________ also accomplish some erosion, transportation and deposition of weathered pieces of Earth material.
Rock structure
The nature, orientation, inclination, and arrangement of affected rock layers
Fold limbs
The rock layers that form the flanks of anticlinal crests and synclinal troughs
Dike
The solidified magma in this case has a wall-like shape and is known as ____
Angle of repose
The steepest angle that a pile of loose material can maintain without rocks sliding or rolling downslope
Focus; 700 km
The subsurface location where rock displacement and the resulting earthquake originate is the earthquake ______, which may be located anywhere from near the surface to a depth of _______
Endogenic processes, exogenic processes, relative strength of resistance of different rock types
The topographic variation on Earth's surface results from the interaction of 3 major factors: _____
aa
This causes the thick layer od hardened crust to break up into sharp-edged, jagged blocks, making a surface known as ____
Geomorphology
Understanding landforms and landscapes - how they originate, why they vary- is the primary goal of __________
Anticlines
Upfolds
Thrust fault
Where compression pushes a mass of rock along a low-angle fault so that it overrides rocks on the other side of the fault, the fracture surface is called ____
Plug dome
Where extremely viscous silica-rich magma pushes up into the vent of a volcanic cone but does not flow farther, it forms ____
Tectonic and igneous processes
______ constitute the endogenic geomorphic processes.
Geoscientists
______ use strike and dip to describe the orientation of tilted rock layers.
0 degree dip
_______ = horizontal
Tectonic and igneous processes
________ and __________ build extensive mountain systems and a great variety of other landforms.
Landforms
________ represent the interplay of one set of processes that elevate, depress, or disrupt Earth's surface.....
Geomorphologists
________ seek explanations for the origin, shape, and spatial distribution of terrain features of all kinds and for the processes that modify and destroy them.
Death Valley, Californa
_________ is a classic example of the downtilted side of a tilted fault block
Exogenic processes
_________ work to decrease relief
Folding
a bending or crumpling of rock layers
Geomorphology
a major subfield of physical geography devoted to the scientific study of landforms
Andesite
a volcanic rock intermediate in silica content and explosiveness between basalt and rhyolite
Vent
almost poplike conduit for the eruption
Magmas
contain large amounts of gases that remain dissolved when under high pressure at great depths
Stress
force per unit area
Felsic magmas
have a higher viscosity than mafic magmas(contain less silica)
Explosive eruptions
violently blast pieces of molten and solid rock into the air
Reverse fault
steep, high-angle fault resulting from compressional force
Earthquake intensity
the damage caused by an eartquake and the degree of its impact on people and their property
Strike-slip fault; Lateral fault
the direction of slippage is parallel to the surface trace, or strike, of the fault; thus it is called a ________, because of the horizontal motion __________
modified Mercalli scale
uses categories numbered from I to XII to describe the effects of an earthquake on humans and the spatial variation of those impacts
Fault scarp
A cliff that results from movement along a fault is specifically a _______ Are commonly visible in the landscape along normal fault zones
Horst
A fault block that moved relatively upward between two normal faults
Relief
A fundamental characteristic of all landforms and landscapes
Caldera
A large depression
Geomorphic agent
A medium that picks up, moves and eventually lays down pieces of broken rock matter.
Pahoehoe
A ropy surface form
Volcanic neck
A tall rock spire made of the now-exposed,formerly subsurface pipe
10; 32
Any whole number increase in earthquake magnitude represents a ___ times increase in amplitude on the seismograph trace, but the actual energy released is about ____ times greater
Batholiths
Are complex masses of solified magma, usually granite
Rift valleys
Are long but relatively narrow zones of crust down dropped between normal faults
Volcanoes
Are mountains or hills that form by volcanism
Tectonism
Areas of the crust can be uplifted or down dropped by ___________
Recumbent folds
Asymmetrically folded rocks may become overturned and perhaps so compressed that the fold lies horizontally, these are known as ______
Ductile
Bendable
Igneous intrusions or plutons
Bodies of magma that exist beneath the surface of earth or masses of intrusive igneous rock that cooled and solidified beneath the surface are ______
Brittle
Breakable
Stratovolcanoes
Composite cones are also known as _______
Landforms
Contribute to the beauty and diversity of Earth's environments
Fissures
Deep fractures in the crust
Fault blocks
Discrete blocks
Synclines
Downfolds
Seismic waves
Energy that moves through Earth
External
Exo: _____
Weathering erosion; transportation;deposition
Exogenic process consist of various means of rock breakdown, collectively termed _______, and the removal, movement and relocation of those weathered rock produces in the continuum of processes known as __________, ________ and _________.
Pyroclastic flows
Fast-moving density currents of airborne volcanic ash, hot gases, and steam that fall downslope
Dip-slip faults
Faults with this kind of movement, up or down along the dip of the fault plane extending into Earth, are known as ___
Pyroclastic materials
Fire fragments. Also reffered to as tephra
Dip
The inclination of the rock layer, _____, is always measured at right angles to the strike and in degrees of angle from the horizontal
Epicenter
Is the point on Earth's surface that lies directly above the focus, and it is where the strongest shock is normally felt
Landforms
Landscapes consist of rugged mountains, gently sloping plains, rolling hills and valleys, or elevated plateaus cut by steep canyons. These are just a few examples of the types of surface terrain features, reffered to as ____________.
Volcanic bombs
Large spindle-shaped clasts that solidified while flying through the air
Ignis
Latin:________, fire
Lava flows
Layers of erupted rock matter that poured or oozed over the landscape when they were molten
Volcanic ash
Like tiny silvers of glass
earthquake safe
Probably no area on Earth can be called "_____"
basaltic plateaus
Relatively flat-topped, but elevated tablelands known as _____
Composite cone
Results when formative eruptions are sometimes effusive and sometimes explosive
Volcanic ash
Sand-sized or smaller (<2mm)
(1) the size of the event as a physical earth process (2) the degree of its impact on humans
Scientists express the severity of an earthquake in 2 distinct ways:
Seismographs
Sensitive instruments that measure ground shaking
Overthrust
Shallow displacement
Cinder cones
Smallest type of volcano, typically only a couple of hundred meters high, consist largely of gravel-sized pyroclastics
Joints
Solidified lava flows tend to have many fractures known as ____
Colorado, Wyoming, Montana, Canadian Rockies
Spectacular folds exist in the Rocky Mountains of _____, _______, and _______ and in the ______
Cinder cone
Steep straight sides and a crater at the top of the hill
Off the coast of Chile, 9.5, 1960
Strongest earthquake, magnitude and when
Compressional tectonic forces Tensional tectonic forces Shearing tectonic forces
Tectonic forces are divided into 3 principal types that differ in the direction of the applied forces. These are ____
Compressional tectonic forces
Tectonic forces that push two areas of crustal rocks together, tend to shorten and thicken rocks
Hawaii
Terms pahoehoe and aa both originated in ______, where effusive eruptions of basalt are common
Relief
The difference in elevation between the highest and lowest points within a specified area or on a particular surface feature
Left lateral; right lateral
The direction of motion along a strike slip fault is described as ______ or ________
Fault
The fracture along which movement has occurred is a ___
Lithospheric plate boundaries
The greatest tectonic forces, most dangerous earthquake zones, and largest mountain ranges lie along ______
Earthquakes
are ground motions of Earth caused when accumulating tectonic stress is relieved by the sudden displacement of rocks along a fault
Sedimentary rocks
are particularly useful for identifying tectonic deformation
Effusive erruptions
molten rock pours less violently onto the surface as flowing streams of lava
Strike
is the compass direction of the line that forms at the intersection of a tilted rock layer and a horizontal plane
Faulting
is the slippage or displacement of rocks along a fracture surface
Silica (SiOsub2)
primary material component that contributes to a higher viscosity in molten rock
Tensional tectonic forces
pull in opposite directions in a way that stretches and thins the impacted part of the crust Commonly cause the crust to break into discrete blocks
Plutonism
refers to igneous processes that occur below Earth's surface, including the cooling of magma to form intrusive igneous rocks and rock masses
Volcanism
refers to the extrusion of rock matter from earth's subsurface to the exterior and the creation of surface terrain features as a result
Viscosity
resistance to flowing
Shield volcano
shape of a large mountain, which resembles a giant knight's shield resting on earth's surface, eruptions are not very explosive
Shearing tectonic forces
slide parts of Earth's crust past each other