Earth Science (Chapter 7-16) Flashcards
Earth Science by Tarbuck, Lutgens, and Tasa
Together with his associates, he constructed a map that pieced together the edges of the continental shelves of South America and Africa.
Edward Bullard
The title of the book written by Alfred Wegener to support the Continental Drift Theory.
The Origin of Continents and Oceans
Divergent and convergent plate boundaries each account for about ________ of all plate boundaries. Transform faults account for the remaining __________.
40 percent; 20 percent
The majority of, but not all, divergent plate boundaries are associated with
mid-oceanic ridges (MOR)
the longest topographic feature on Earth’s surface, exceeding 70,000 kilometers (43,000 miles) in length.
Global ridge system
along the crest of some ridge segments is a deep canyonlike structure called
rift valley
Typical rates of seafloor-spreading average around ______ per year.
5 centimeters (2 inches)
Where can we found fastest and slowest spreading rates.
15cm/yr - East Pacific Rise; 2cm/yr Mid-Atlantic Ridge
the tallest peaks in Africa
Mount Kilimanjaro and Mount Kenya
A volcanic arc in Atlantic that forms through the subduction of the Atlantic seafloor beneath the Caribbean plate.
Lesser Antilles arc
An island arc located off the tip of South America.
Sandwich Islands
The nature of transform faults was discovered in 1965 by Canadian geologist ______.
J. Tuzo Wilson
When did the Arabian plate begin to split from Africa forming the Red Sea?
20 million years ago
the last remnant of a once vast ocean called Tethys Ocean
Mediterranean sea
a drilling ship capable of working in water thousands of meters deep, was built for Deep Sea Drilling Project from 1968-1983.
Glomar Challenger
IODP means
Integrated Ocean Drilling Program (IODP).
The two drilling ships that was utilized in IODP.
JOIDES Resolution (2003) and Chikyu (2007)
The major divisions of the mag netic time scale last roughly 1 million years.
chrons
This convection is a driving force for the movement of tectonic plates, asthe horizontal movements of mantle under the crust drag the plates with them.
Mantle drag
He concluded that the earthquake must have involved an “elastic rebound” of previously stored elastic stress.
H. F. Reid of Johns Hopkins University
Large strike-slip faults that slice through Earth’s lithosphere and accommodate motion between two tectonic plates
Transform Fault
San Andreas fault separates what plates?
North American and Pacific Plate
the plate boundary between a subducting slab of oceanic lithosphere and the overlying plate form a fault referred to as
megathrust fault
The earliest known instrument used to measure earthquakes are made by?
Zhang Heng
How wide is the maximum area from the epicenter that an earthquake can be felt roughly?
20 to 50 kilometers
An earthquake that provided geologists with insights into the role of ground shaking as a destructive force.
1964 Alaskan earthquake, also known as theGreat Alaskan earthquakeand Good Friday earthquake
What type of faulting triggered the 1964 Alaskan earthquake?
megathrust fault It had a moment magnitude of 9.2, making it the second largest earthquake on record.
The zone of greatest seismic activity is called?
circum-Pacific belt
The circum-Pacific belt encompasses the coastal regions of?
Chile, Central America, Indone sia, Japan, and Alaska, including the Aleutian islands
A major concentration of strong seismic activity that runs through the mountainous regions that flank the Mediterranean Sea and extends past the Himalayan Mountains
Alpine–Himalayan belt
The last major earthquke event in San Andreas Fault that occurred in Pallet Creek segment in 1857, roughly 150 years ago.
Fort Tejon
Lavas that have have surfaces of rough, jagged blocks with dangerously sharp edges and spiny projections.
Aa lava
What is the diameter of a caldera?
more than 1km
From its base on the floor of the Pacific Ocean to its summit, Mauna Loa is over_________ high, exceeding the elevation of Mount Everest.
9 kilometers (6 miles)
Most of the recent activity on Kilauea has occurred along the flanks of the volcano, in a region called
East Rift Zone
A cinder and spatter cone that formed when the eruption of Mt. Kilauea became localized at a single vent and a series of 44 short-lived episodes of lava fountaining
Puu Oo
A cinder cone located in Mexico, erupted for nine years.
Parícutin
Well known for eruptions that eject incandescent blobs of lava that it has been referred to as the “Lighthouse of the Mediterranean.”
Stromboli
When was the most recent volcanic activity of Mt. Vesavius?
1944
Refers to dense cloud of tiny sulfuric-acid droplets. Like fine ash, they can alsolower the mean temperature of the atmosphere by reflecting solar radiation back to space.
aerosols
Other term for craters
collapse pits
Term used for intrusions that cut across existing structures
discordant
It refers to an intrusion if they inject parallel to features such as sedimentary strata
concordant
These are discordant bodies that cut across bedding surfaces or other structures in the country rock
Dikes
Refers to nearly horizontal, concordant bodies that form when magma exploits weaknesses between sedimentary beds or other structures
Sills
The thickness of dikes and sills ranges from
less than 1 millimeter to more than 1 kilometer
While dikes and sills can occur as solitary bodies, dikes tend to form in roughly parallel groups called
dike swarms
occurs when igneous rocks cool and develop shrinkage frac tures that produce elongated, pillar-like columns that most often have six sides
Columnar jointing
A plutonic body must have a surface exposure of ________ in order to be considered a batholith
greater than 100 square kilometers
Smaller plutons are termed as
stock
Who gave the name laccoliths?
G. K. Gilbert
A mass ofigneousrock, typically lens-shaped, that has beenintrudedbetween rockstratacausingupliftin the shape of a dome.
Laccoliths
What is the temperature for geothermal gradient?
25°C per kilometer in the upper crust
Occurs where hot, solid mantle rock ascends in zones of convective upwelling, thereby mov ing into regions of lower pressure
Decompression melting
Most intraplate volcanism occurs where a mass of hotter-than-normal mantle material called
Mantle Plumes
A general term that refers to the changes in the shape or position of a rock body in response to differential stress.
Deformation
stress is applied uniformly in all directions
confining pressure
stress is applied unequally in different directions
differential stress
A change in shape caused by stress.
strain
Each layer of a fold is bent around an imaginary axis called a
hinge line
These are produced by rapid vertical slips in dip-slips that generate earthquakes.
fault scarps
when the hanging wall block moves down relative to the footwall block
normal fault
produced by alternating uplifted fault blocks
horst
down-dropped fault blocks
graben
fault blocks that have been tilted
half-grabens
the slopes of the large normal faults associated with the Basin and Range Province decrease with depth and eventually join to form a nearly horizontal fault called
Detachment fault
strike-slip faults that slice through Earth’s crust and accommodate motion between two tectonic plates
Transform Fault
fractures along which no appre ciable displacement has occurred
joints
This type of mountain building is characterized by subduction beneath a continent rather than oceanic lithosphere.
Andean-type mountain Building
The resulting chaotic accumulation of deformed and thrust-faulted sediments and scraps of ocean crust
Accretionary wedge
As an accretionary wedge grows upward, it acts as a barrier to the movement of sediment from the volcanic arc to the trench. As a result, sediments begin to collect between the accretionary wedge and the volcanic arc. This region, which is composed of relatively undeformed layers of sediment and sedimentary rocks
forearc basins
a crustal fragment that consists of a distinct and recognizable series of rock formations that has been transported by plate tectonic processes.
terrane
eastern portion of the Pacific basin
Farallon plate
Much of the remaining penetration into Asia caused lateral displacement of large blocks of the Asian crust by a mechanism described as
continental escape
The Laramide Rockies in Rocky Mountains was produced duringa period of deformation known as the
Laramide Orogeny
involves ductile spreading at depth and normal faulting and subsidence in the upper, brittle portion of Earth’s crust.
gravitational collapse
Combining the principles of lateral continuity and superposition lets us extend relative age relationships over broad areas. This pro cess, called
correlation
Refers to a piece of rock trapped in another type of rock.
xenolith
These are “foreign” minerals incorporated into the magma during magma scent or during xenoliths fragmentation.
xenocrysts
When we observe layers of rock that have been deposited essentially without interruption, we call them
conformable
Represents a long period during which deposition ceased, erosion removed previously formed rocks, and then deposi tion resumed
unconformity
Where can we find fossils of mammoth?
Arctic tundra of Siberia and Alaska
Where can we find fossils of sloths?
dry cave in Nevada
When mineral-rich groundwater permeates porous tissue such as bone or wood, minerals precipitate out of solution and fill pores and empty spaces, a process called
permineralization
When a shell or another structure is buried in sediment and then dissolved by underground water, a ______ is created
mold
If these hollow spaces are subsequently filled with mineral matter, ______ are created
casts
Animal footprints made in soft sediment that later turned into sedimentary rock.
Tracks
Tubes in sediment, wood, or rock made by an animal. These holes may later become filled with mineral matter and preserved.
Burrows
Some of the oldest-known fossils are believed to be
worm burrows
Fossil dung and stomach contents that can provide useful information pertaining to the size and food habits of organisms
Coprolites
Highly polished stomach stones that were used in the grinding of food by some extinct reptiles
Gastroliths
To develop a geologic time scale that is applicable to the entire Earth, rocks of similar age in different regions must be matched up. Such a task is referred to as
correlation
a fossil that is useful for dating andcorrelatingthestratain which it is found
index fossil
Fossils that provide geological records of the activities and behaviors of past life. Some examples include rock evidence of nests, burrows, footprints, and scat.
trace fossils
other term for trace fossils
Ichnofossils
Refers to the fossils of bones, teeth, and shells.
body fossils
the property of some unstable atoms (radionuclides) to spontaneously emit nuclear radiation
radioactivity
It refers to the earliest interval (eon) of Earth history—before the oldest-known rocks.
Hadean
When the term “Hadean” was coined in 1972, the age of Earth’s oldest rocks was thought to be about
3.8 billion years
A well-known fossil of a human ancestor _________ was discovered in Ethiopia and is 3.2 million years old. The oldest bones thus far assigned to the human genus Homo, are from the early Pleistocene epoch and are about 2.4 million years old.
(Australopithecus afarensis) known as Lucy
This early atmosphere was enhanced by a process called __________, through which gases trapped in the planet’s interior are released
outgassing
alternating layers of iron-rich rocks and chert
banded iron formations
what era did the Great Oxygenation Event occur
Paleoproterozoic era of the Precambrian period
One apparent spike in oxy gen levels occurred during the _________, when oxygen made up about 35 percent of the atmosphere, compared to modern levels of only 21 percent.
Pennsylvanian period (300million years ago)
Another positive benefit of the Great Oxygenation Event is
oxygen molecules (O2) readily absorb ultraviolet radi ation and form ozone (O3)
The oldest-known sample of Earth is a 4.4-billion year-old zircon crystal can be found in
a metaconglomerate in the Jack Hills area of western Australia.
The large landmass in the Southern Hemisphere called Gondwana, comprised mainly of present day
South America, Africa, India, Australia, and Antarctica
The cold current, called ______, effectively isolated the entire Antarctic coast from the warm, poleward-directed currents in the southern oceans. As a result, most of the Antarctic landmass became covered with glacial ice.
West Wind Drift
In what period did the Gondwana and Laurasia collided forming Pangaea
Permian - Triassic
Considered as the world’s richest storehouse of dinosaur fossils. In what period did it formed?
Morrison Formation - Jurassic
The first known organisms were simple single-cell bacteria
prokaryotes
stony structures built by colonies of microscopic photosynthesising organisms called cyanobacteria
Stromatolite
This period was the golden age of trilobites
Cambrian
Trilobites developed a flexible exoskel eton of a protein called
chitin
