A combination of snow and dirt. snirtballs are produced by accident when the total snowfall on bare ground is less than 0.537 inches.
A combination of snow and rock
|glacial quarrying (plucking)|
A common mechanical weathering process in alpine glaciated terrain where glacial ice frozen into cracks in the bedrock literally "pluck" rock material from the valley floor.
A continuous release of seismic energy typically associated with the underground movement of magma. it contrasts distinctly with the sudden release and rapid decrease of seismic energy associated ...
A copmmon mechanical weathering process where rock and debris frozen into the sides and bottom of a glacier act like sandpaper and wear down the bedrock the glacier is mocing across.
|marker horizon (or bed)|
A distinctive horizon which is used for regional correlation of lithology. a good marker horizon is distinctive, widespread, and represents a relatively short period of geologic time. for example,...
A flow of unsorted masses of rock and other material downslope under the influence of gravity. water is commonly involved as a catalyst and/or lubricant. for example
- A flowage of water-saturated earth material possessing a high degree of fluidity during movement. a less-saturated flowing mass is often called a debris flow. a mudflow originating on the flan...
A french term applied to a highly heated mass of gas-charge ash which is expelled with explosive force down the mountainside. common to intermediate volcanoes. can be quite deadly. also known as a...
- A general term for clay, silt, sand, gravel or similar unconsolidated material deposited by a stream or other body of running water.
- Gravel, sand, silt, soil, or other material that...
- A gently sloping volcano in the shape of a flattened dome, built almost exclusively of mafic lava flows. the hawaiian islands are a good example.
- A volcano having the shape of a ver...
- A geologic formation or stratum that significantly retards fluid movement.
- A body of rock or sediment that retards but does not prevent the flow of water to or from an adjacent aqui...
A large igneous intrusion formed at great depth in the crust. плутон;
A major submarine mountain range. commonly the sites of crustal rifting and plate separation, and the eruption of mafic basaltic lavas.
A nearly vertical fault with side-slipping displacement. сбросо-сдвиг;
A snowball which has been stored in the freezer for several months (or more). useful for surprising unwelcome visitors during the spring and summer months.
A steep volcanic cone built by both lava flows and pyroclastic eruptions.
- A torrential flow of water-saturated volcanic debris down the slope of a volcano in response to gravity. a type of mudflow.
- The process, associated sediments or resultant landform c...
- A tunnel formed when the surface of a mafic lava flow cools and solidifies, while the still-molten interior flows through and drains away. these can insulate the flow and allow it to travel gr...
A turbulent mixture of gas and rock fragments, most of which are ash-sized particles, ejected violently from a crater or fissure. the mass of pyroclastics is normally of very high temperature and ...
A vent or opening through which issue steam, hydrogen sulfide, or other gases. the craters of many dormant volcanoes contain active fumaroles. фумарола;
- A volcanic cone built entirely of loose fragmented material (pyroclastics.)
- A conical hill formed by the accumulation of cinders and other pyroclastics, normally basaltic or andesit...
- A volcano composed of both lava flows and pyroclastic material. also called "composite" volcanoes. common at convergent boundaries. excellent examples in the u.s. include mt. st. hel...
A volcano that is erupting; or one that, while not erupting at the present, has erupted within (geologically) recent time and is considered likely to do so in the (geologically) near future.
A volcano that is not presently erupting and is not likely to do so for a very long time in the future.
An aquifer containing unconfined groundwater separated from an underlying body of groundwater by an unsaturated zone.
|aquifer, unconfined (or water table)|
An aquifer in which the upper surface is the water table.
|aquifer, confined (or artesian)|
An aquifer overlain by a non-permeable layer or layers, in which pressure will force water to rise above the aquifer.
- An elongate crustal block that is relatively depressed (downdropped) between two fault systems.
- An elongate trough or basin bounded on both sides by high-angle, normal faults that d...
An eruption from the side of a volcano (in contrast to a summit eruption.)
An estimate of the true age of a mineral or rock based on the rate of decay of radioactive minerals.
An explosive eruption in which the resultant cloud of hot ash and other material moves laterally rather than upward.
|phreatic eruption (explosion)|
An explosive volcanic eruption caused when water and heated volcanic rocks interact to produce a violent expulsion of steam and pulverized rocks. magma is not involved.
An igneous rock with mafic composition. норит;
- An impermeable geologic formation or stratum which will not hold or transmit fluid.
- Водоупорный горизонт
- A layer of soil, sediment, or rock that may or may not be saturat...
- An instrument that records seismic waves; that is, vibrations of the earth. used to record and measure earthquakes.
- Drill. a rotary drill, pump, and hinged mast mounted as an integr...
- An outpouring of lava onto the surface from a vent or fissure. also, a solidified tongue-like or sheet-like body formed by outpouring lava.
- A solidified body of rock formed from the...
An underground zone of porous rock containing hot water.
- Angular fragments of material, commonly formed by physical weathering processes or explosive volcanic activity.
- Any stone composed of angular fragments embedded and consolidated in ...
Any aquifer that is not the main source of water to wells in a given area.
Energy derived from the internal heat of the earth.
Erosional features associated with alpine glaciers.
Evidence of past life on earth. can include the preserved hard and soft parts of plants and animals, tracks and burrows, whole organisms preserved intact in amber or tar, and fossilized dung. any ... ископаемое; ископаемое, окаменелость;
- Finely ground rock material, usually associated with glaciers (or faults). can be mixed with water and formed into loaves which, when baked for 45 minutes at 350°, are totally unedible.
From the greek "meta" (change) and "morph" (form). commonly occurs to rocks which are subjected to increased heat and/or pressure. also applies to the conversion of snow into g... метаморфический; метаморфические;
- General term for material deposited beneath, along the sides, and/or at the terminus of a glacier. also, what we get here in oregon during the fall, winter, and spring. see also till.
General term for material deposited by a glacier.
General term for material deposited by a glacier. see also moraine.
Grooves eroded into bedrock by rock debris frozen into the base of a glacier.
Hawaiian term for a fluid volcanic eruption resulting in broad basaltic shield volcanoes. the highly fluid magma flows readily, and hardens into ropey forms as it cools. it can be very impressive ... пахоехое;
Holes and other openings in basaltic flow which are the result of trapped gas bubbles. vesicles are often filled at a later date with a wide variety of materials, including, quartz, agate, zeolite...
Horn-like projections formed upon a lava dome.
- Interconnected, sack-like bodies of lava that form underwater.
- A general term for lava displaying pillow structure (discontinuous, close-fitting, bun-shaped or ellipsoidal masses, g...
- Intermediate volcanic rocks containing 54 to 62 percent silica and moderate amounts of iron and magnesium. andesite minerals commonly include plagioclase and hornblende, with lesser amounts of...
Large rocks or other debris deposited by a glacier, usually in an area far removed from its source. commonly used to indicate a big chunk of debris which is clearly out of place and shouldn`t even...
- Lateral flowage of a turbulent mixture of hot gases (≈400°c) and unsorted pyroclastic material (volcanic fragments, crystals, ash, pumice, and glass shards) that can move at high spe...
- Light-colored, frothy volcanic rock, usually of dacite or rhyolite composition, formed by the expansion of gas in erupting lava. commonly seen as lumps or fragments of pea-size and larger, but...
- Literally, "little stones;" round to angular rock fragments measuring 1/10 inch to 2-1/2 inches in diameter, which may be ejected in either a solid or molten state.
- Non or...
Making little ones out of big ones. waethering includes the processes which mechanically and chemically break down the mountains into little pieces, so they can be eroded and transported to the be...
Material that is thrown out by a volcano, including pyroclastic material (tephra) and, from some volcanoes, lava bombs.
- Materials of all types and sizes that are erupted from a crater or volcanic vent and deposited from the air.
- A collective, general term for any and all clastic materials, regardless...
- Molten rock beneath the surface of the earth.
- Molten material generated with the crust or upper mantle from which igneous rocks are derived by solidifica- tion, and that is capable ...
Naturally occurring ice which exhibits internal plastic flow and deformation.
|plastic deformation (or flow)|
Permanent bending or folding of rock (or ice) as a result of directed pressure. in rock, usually occurs below the brittle-ductile transition zone, and is commonly associated with metamorphism.
- Pertaining to fragmented (clastic) rock material formed by a volcanic explosion or ejection from a volcanic vent.
- An igneous rock composed of angular rock fragments that originate f...
Polished bedrock surfaces left behind after melting of glacial ice. the polishing is probably due to very fine grained rock flour carried at the base of the ice.
Power generated by using the heat energy of the earth.
Rock formed of pyroclastic material. туф;
Roman god of fire and the forge, after whom volcanoes are named.
- Solid, outer layers of the earth, including the rocks of the continents.
- The portion of the earth’s crust that un- derlies the continents and continental shelves, ranging from about...
Solidified lava that fills the conduit of a volcano. volcanic necks (also called plugs) are usually more resistant to erosion than the material making up the surrounding cone, and may remain stand...
The aquifer or combination of related aquifers in a given area that is the important economic source of water to wells.
The arrangement of the hydrogen atoms of a water molecule at 105 deg. across the oxygen results in a slight electrical charge to the molecule. it also results in water molecules looking like micke...
The column of gases, ash, and larger rock fragments rising from a crater or other vent. if it is of sufficient volume and velocity, this gaseous column may reach many miles into the stratosphere, ...
- The earth`s crust where it underlies oceans.
- The portion of the earth’s crust that under- lies the ocean basins, and that ranges in thickness from about 5 to 10 km.
The energy of motion. кинетическая энергия;
|brittle-ductile transition zone|
The location at depth within the earth`s crust where the temperature and pressure have risen to such a high level that directed stress results in plastic deformation as opposed to fracturing and f...