Exam 1 Chapters I-3 Flashcards
Ch I
Hypothesis
An idea or theory that is unproven
Ch I
Theory
A well-tested and widely accepted view
Ch 1
Mineral
Any naturally occurring inorganic solid that possesses an orderly crystalline structure and a definite chemical composition that allows for some variation
Ch 1
Silicates
A combination of oxygen and silicon which form the basic building blocks of the most common mineral group: silicates
Ch 1
Silicon-oxygen tetrahedron
A structure that consists of four oxygen ions that are covalently bonded to a comparatively smaller silicon ion forming a tetrahedron
Ch 1
Covalent bond
Involves the sharing of one or more electrons between two adjacent atoms
Ch 2
Magma
Forms by melting that occurs primarily within earth’s crust and upper mantle
Ch 2
Weathering
The slow disintegration and decomposition of rocks by the daily influences of the atmosphere
Ch 2
Metamorphism
“To change form”
A process that leads to changes in the mineralogy, texture (i.e. Grain size), and sometimes chemical composition of rocks subjected to high temperatures and pressures within Earth
Ch 2
Mineral Composition
Granitic, andesitic, basaltic
Ch 3
Mass wasting
The transfer of rock and soil downslope under the influence of gravity
Ch 3
Erosion
The physical removal of material by a mobile agent such as flowing water, waves, wind, or glacial ice
Ch 3
Deposition
The process by which water vapor is changed directly to a solid, without passing through the liquid state.
Ch 3
Deltas
A delta forms where a sediment-charged stream enters the relatively still waters of an ocean, lake, or inland sea. The forward motion slows and as the delta grows outward, the stream’s gradient lessens and the channel becomes choked with sediment
Ch 3
Porosity
The percentage of the total volume of rock or sediment that consists of pore spaces
Ch 3
Aquifer
Permeable rock strata or sediments that transmit groundwater freely. They are the water-bearing layers sought after by well drillers.
Ch 4
Till
Unsorted material deposited directly by the ice
Ch 4
Moraine
Layers or ridges of till
Ch 4
Drift
Sediments of glacial origin
1) materials deposited directly by a glacier (till)
2) sediments laid down by glacial meltwater (stratified drift)
Ch 4
Loess
Deposits of windblown silt that are lacking visible layers, generally buff-colored, and capable of maintaining a nearly vertical cliff. Two primary sources: deserts and glacial deposits of stratified drift
Ch 5
Continental Drift
A theory which originally proposed that the continents are rafted about. It has essentially been replaced by the plate tectonic theory
Ch 5
Divergent plate boundary
A region where the rigid plates are moving apart, typified by the mid-ocean ridges
Ch 5
Convergent plate boundaries
A boundary in which two plates move together, causing one of the slabs of lithosphere to be consumed into the mantle as it descends beneath an overriding plate
Ch 5
Transform plate boundary
A boundary in which two plates slide past one another without creating or destroying lithosphere
Ch 5
Lithosphere
The rigid outer layer of earth including the crust and the upper mantle
Ch 5
Asthenosphere
A subdivision of the mantle situated below the lithosphere. It is flexible and can move very slowly
Ch 5
Rift
A region of earth’s crust along which divergence is taking place
Ch 5
Hot Spots
A concentration of heat in the mantle that is capable of producing magma, which in turn extrudes into Earth’s surface
Ch 5
Convection Currents
The transfer of heat by the movement of a mass or substance which can take place only in fluids
Ch 6
Earthquake
Vibration of earth produced by the rapid release of energy
Ch 6
Fault
A break in a rock mass along which movement has occurred
Ch 6
Magnitude
In seismology: the total amount of energy released during an earthquake
Ch 6
Tsunamis
A rapidly moving ocean wave generated by earthquake activity that is capable of inflicting heavy damage in coastal regions
Ch 6
Crust
The very thin outermost layer of earth
Ch 6
Mantle
The 2900 km thick layer of earth located below the crust
Ch 6
Core
The innermost layer of earth, based on composition. It is though to be largely an iron-nickel alloy, with minor amounts of oxygen, silicon, and sulfur
Ch 6
Deformation
General term for the processes of folding, faulting, shearing, compression, or extension of rocks
Ch 7
Viscosity
A measure of a fluid’s resistance to flow
Ch 7
Shield volcano
A broad, gently sloping volcano built from fluid basaltic lavas
Ch 7
Composite volcano
A volcano composed of both lava flows and pyroclastic material
Ch 7
Caldera
A large depression typically caused by collapse or ejection of the summit area of a volcano
Ch 7
Pyroclastics
The volcanic rock ejected during an eruption including ash, bombs, and blocks
Ch 8
Relative Date
Rocks placed in their proper sequence or order of formation based on geologic principles
Ch 8
The Principle of Superposition
Sediment that is on top is younger than sediment underneath it
Ch 8
Cross-cutting relationships
A principle of relative dating which states that a rock or fault is younger than any rock or fault through which it cuts
Ch 8
The principle of horizontality
A principle by which layers of sediment are generally deposited in a horizontal or nearly horizontal position
Ch 8
Unconformities
A surface that represents a break in the rock record caused by erosion or nondeposition
Ch 8
Index fossils
A fossil that is associated with a particular span of geologic time
Ch 8
Correlation
The establishment of the equivalence of rocks of similar age in different areas
Ch 8
Half-life
The time required for one-half of the atoms of a radioactive substance to decay
Ch 8
Radioactivity
The process by which atomic nuclei spontaneously break apart. Used to calculate the ages of rocks and minerals that contain radioactive isotopes
