Geology Flashcards
It is a dynamic planet and constantly changing structure; and is a layered sphere.
Earth
Layer of Earth (3 answers)
- Core
- Mantle
- Crust
or interior, is composed of a dense, intensely hot mass of metal, mostly
iron, thousands of kilometers in diameter.
Core
is surrounding the molten outer core. It is a hot, pliable layer of rock.
Mantle
is the cool, lightweight, brittle rock outermost layer of the earth.
Crust
8 most common Chemical Elements
- iron
- oxygen
- silicon
- magnesium
- nickel
- calcium
- aluminum
- sodium
In 1885, _____went so far as to publish a sketch showing how the two
continents could fit together, jigsaw-puzzle fashion.
Antonio Snider
Climatologist ______ was struck not only by the matching coastlines, but by geologic evidence from the continents.
Alfred Wegener
It may preserve evidence of the ancient climate of the time and
place in which this were deposited. Such evidence shows that the climate in many places has varied widely through time. It also preserve fossil remains of ancient life. Some plants and animals, long extinct, seem to have lived only in a few very restricted areas, which now are widely separated geographically on different continents.
Sedimentary rocks
remains of which are found in limited
areas of widely separated lands including India, southern Africa, and even Antarctica.
Glossopteris
A supercontinent (Greek for “all lands”)
Pangaea
Wegener proposed that all the continental landmasses had once formed a single supercontinent, Pangaea (Greek for “all lands”), which had then split apart, the modern continents moving to their present positions via a process called
continental
drift.
Continental “drift” turned out to be just one consequence of processes encompassed by a broader theory known as. It relates such deformation to the existence and movement of rigid “plates” over a weaker, more plastic layer in the earth’s upper mantle.
plate tectonics
is the study of large scale movement and deformation of the earth’s outer
layers.
Tectonics
The earth’s crust and uppermost mantle are somewhat brittle and elastic.
Together they make up the outer solid layer of the earth called the ______,
from the Greek word lithos , meaning “rock.”
lithosphere
Lithosphere is thinnest underneath the oceans, where it extends to a depth of about _____
50 kilometers (about 30 miles).
Lithosphere under the continents is both thicker on average than is oceanic
lithosphere, and more variable in thickness, extending in places to about
250
kilometers (over 150 miles).
The layer below the lithosphere is the ____, which derives its name
from the Greek word asthenes, meaning “without strength.”
asthenosphere
The asthenosphere extends to an average depth of about ________ in the mantle.
300 kilometers (close to
200 miles)
Type of Plate Boundaries (3 answers)
- Convergent Plate Boundaries
- Divergent Plate Boundaries
- Transform Boundaries
lithospheric plates MOVE APART.
Divergent plate boundary
are the most common type of divergent boundary worldwide, and it is already noted the formation of new oceanic lithosphere at these ridges.
SEAFLOOR SPREADING RIDGES
If the continental rifting continues, a new ocean basin will form between the
pieces of the continent as shown in above figure. This is happening now in
northeast Africa, where three rift zones meet in what is called a ________.
triple junction
plates are MOVING TOWARD EACH OTHER.
Convergent plate boundary
Continental crust is relatively low in density, so continental lithosphere is
therefore buoyant with respect to the dense, iron rich mantle, and it tends to
“_____” on the asthenosphere.
float
This type of plate boundary, where one plate is carried down below (subducted
beneath) another, is called a ___________.
subduction zone
At an ocean-ocean convergence, the result is commonly a line of volcanic islands
island arc
The offset is a special kind of fault, or break in the lithosphere, known as a
transform fault.
is a naturally occurring, inorganic, solid element or compound with a
definite chemical composition and a regular internal crystal structure.
mineral
are solids in which the atoms or ions are arranged in regular, repeating patterns.
Crystalline materials
The two fundamental characteristics of a mineral that together distinguish it from all other minerals are its: (2)
- chemical composition
- crystal structure
A mineral’s composition and crystal structure can usually be determined only by
__________.
using sophisticated laboratory equipment
Types of Minerals (2 answers)
- silicates
- nonsilicates
group is the largest compositional group of minerals, all of which are compounds containing silicon and oxygen, and most of which contain other elements as well.
Silicate
Two most common elements in the
earth’s crust are ______.
silicon and oxygen
Silicate Minerals (5 answers)
- Quartz
- Feldspars
- Ferromagnesian
- Micas
- Clays
- probably the best known silicate.
Compositionally, it is the simplest,
containing only silicon and oxygen. It is a framework silicate, with silica tetrahedra linked in three dimensions, which helps make it relatively hard and weathering resistant.
Quartz
- The most abundant group of minerals in
the crust is a set of chemically similar minerals. They are
composed of silicon, oxygen, aluminum, and either
sodium, potassium, or calcium, or some
combination of these three.
Feldspars
- The general term used to
describe those silicates—usually dark-colored (black, brown, or green)— that contain iron and/or magnesium, with or without additional elements.
Ferromagnesian
are another group of several silicate minerals with similar physical
properties, compositions, and crystal
structures. These are sheet silicates, built on an atomic scale of stacked-up sheets of linked silicon and oxygen atoms.
Micas
are another family within the sheet
silicates, the sheets tend to slide
past each other, a characteristic that contributes to the slippery feel of
this material and related minerals. these are somewhat unusual among the silicates in that their structures can absorb or lose water, depending on how wet conditions are.
Clays
group is defined by some chemical constituent or characteristic that all members of the group have in common. Most often, the common component is the same negatively charged ion or group of atoms.
nonsilicate mineral
is a solid, cohesive aggregate of one or more minerals, or mineral materials.
rock
Categories of Rocks: The three broad categories of rocks— (3 answers) —
are distinguished by the processes of their formation.
- igneous rocks
- SEDIMENTS & SEDIMENTARY ROCKS
- metamorphic rocks
is a rock formed by the solidification and crystallization of a cooling magma.
igneous rock
is the name given to naturally occurring hot, molten rock material.
Silicates are the most common minerals, so _____ are usually rich in silica. They also contain some dissolved water and gases and generally have some solid crystals suspended in the melt.
Magma
Examples of Igneous Rock (2 answers)
Plutonic Igneous Rock
Volcanic
The name is derived from Pluto, the Greek god of the lower world. Granite is probably the most widely
known example of a this rock
Plutonic Igneous Rock
A magma that flows out on the earth’s surface while still wholly or partly molten is called
lava
Lava is a common product of volcanic
eruptions, and the term _____ is given to an igneous rock formed at
or close to the earth’s surface.
volcanic
The most common volcanic rock, a dark rock rich in ferromagnesian minerals and feldspar.
basalt
sediments are compacted or cemented together into a solid, cohesive mass. This formed at low temperatures.
sedimentary rocks
are loose, unconsolidated accumulations of mineral or rock particles that have been transported by wind, water, or ice, or shifted under the influence of gravity, and redeposited.
Sediments
The set of processes by which sediments are transformed into rock is collectively described as
(from the Greek word lithos, meaning “stone”). The resulting rock is generally more compact and denser, as well as more cohesive, than the original sediment.
lithification
Sedimentary rocks are formed at or near the earth’s surface, at temperatures close to ordinary surface temperatures. They are subdivided into two groups
clastic and chemical.
Formed from the products of the mechanical breakup of other rocks. Natural processes continually attack rocks exposed at the surface. Rain and waves pound them, windblown dust scrapes them, frost and tree roots crack them—these and other processes are all part of the physical weathering of rocks.
Clastic sedimentary rocks
, is a rock composed of sand-sized sediment particles, 16 to 2
millimeters (0.002 to 0.08 inches) in diameter.
Sandstone
is made up of finer-grained sediments, and the individual grains
cannot be seen in the rock with the naked eye.
Shale
is a relatively coarse-grained rock, with fragments above 2 millimeters (0.08 inches) in diameter, and sometimes much larger.
Conglomerate
o Form not from mechanical breakup and transport of fragments, but from
crystals formed by precipitation or growth from solution.
Chemical sedimentary rocks
Examples of chemical sedimentary rocks: (2 answers)
Limestone,
Rock Salt
is composed mostly of calcite (calcium carbonate). Its chemical sediment may be deposited from fresh or salt water
Limestone
, made up of the mineral halite, which is the mineral name for
ordinary table salt (sodium chloride). A salt deposit may form when a
body of salt water is isolated from an ocean and dries up
Rock salt
Some chemical sediments have a large biological contribution. A sequence of sedimentary rocks may include layers of ________ , carbon-rich
remains of living organisms;
organic sediments
this rock is one that has formed from another, preexisting rock that was subjected to heat and/or pressure.
METAMORPHIC ROCKS
describe, respectively, a metamorphosed conglomerate and a metamorphosed volcanic rock.
Metaconglomerate and metavolcanic
is a quartz-rich metamorphic rock, often formed from a very quartzrich sandstone.
Quartzite
is metamorphosed limestone in which the individual calcite grains have recrystallized and become lightly interlocking.
Marble
can be used for any metamorphic rock rich in amphibole.
amphibolite
The resultant texture is described as, from the Latin for “leaf”.
foliation
is metamorphosed shale that has developed foliation under stress.
Slate
—a schematic view. Basically, a variety of geologic processes can
transform any rock into a new rock of the same or a different class.
The rock cycle
is the study of resources that are valuable for manufacturing and are,
therefore, an important part of domestic and international commerce.
Economic mineralogy
minerals with unusually high concentrations of metals.
metal bearing ores
are a broad class that covers resources from silicate minerals
(gemstones, mica, talc, and asbestos) to sand, gravel, salts, limestone, and soils.
Nonmetal minerals
An ancient method of accumulating gold, diamonds, and coal is
placer mining
Another ancient, and much more dangerous, method is ______—.
underground mining
are used to extract massive beds of metal ores and other minerals.
Open-pit mines
Half the coal used in the United States comes from and found in expansive, horizontal beds, the entire land surface can be stripped away to cheaply and quickly expose the coal.
surface or strip mines
a coal mining method mainly practiced in Appalachia. Long, sinuous ridge-tops are removed by giant mining machines to expose
horizontal beds of coal
Over mountaintop removal
or roasting ore to release metals—is a major source of air pollution.
Smelting
which is often used to get metals from low-grade ore, has a high potential for environmental contamination. A cyanide solution sprayed on a large pile of ore to dissolve gold can leak into surface or ground water.
Heap-leach extraction
offers great potential for extending our supplies of economic minerals
and reducing the effects of mining and processing.
Conservation
The advantages of conservation are also significant: (3 answers)
- Less waste to dispose of
- Less land lost to mining
- Less consumption of money, energy, and water resources.
is slowly increasing as raw materials become more scarce and wastes
become more plentiful.
Recycling
the catalyst in automobile catalytic exhaust converters, is valuable
enough to be regularly retrieved and recycled from used cars.
Platinum
A new type of mill subsisting entirely on a readily available supply of scrap/waste
________is a growing industry.
steel and iron
Its introduction has decreased our consumption of copper, lead, and steel pipes.
plastic pipe
are sudden movements in the earth’s crust that occur along faults
(planes of weakness) where one rock mass slides past another one, as was the case along the Enriquillo– Plantain Garden Fault in Haiti.
Earthquakes
Geological Hazards: (6 answers)
- Earthquakes
- Tsunamis
- Volcanoes
- Landslide
- Floods
- Beach erosion
are giant sea waves triggered by earthquakes or landslides.
Tsunamis
and undersea magma vents produce much of the earth’s crust.
Volcanoes
is a general term for rapid downslope movement of soil or rock.
Landslide
are normal events that cause damage when people get in the way.
Floods
occurs on all sandy shorelines because the motion of the waves is
constantly redistributing sand and other sediments.
Beach erosion
- refers to atmospheric conditions that occur locally over short periods of time—from minutes to hours or days.
Weather
- refers to the long-term regional or even global average of temperature, humidity
and rainfall patterns over seasons, years or decades.
Climate
Gases that contribute to the greenhouse effect include: (5 answers)
Water vapour
Carbon Dioxide
Methane
Nitrous Oxide
Chlorofluorocarbons
- The long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere.
Global Warming
- A long-term change in the average weather patterns that have come to define Earth’s local, regional and global climates.
Climate Change
“without strength”
Asthenes
greek word which means “changed form”
metamorphic
“broken”
klastos
