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GEOL PREP TEST2
SOIL VOLCANO IGNEOUS ROCKS
Question | Answer |
---|---|
A layer of soil that has identifiable characteristics produced by chemical weathering and other soil-forming processes | soil horizon |
A vertical section through a soil, showing its succession of horizons and the underlying parent material | soil profile |
A compositional group of igneous rocks, indicating that the rock contains at least 25 percent dark silicate minerals. The other dominant mineral is plagioclase feldspar | Intermediate composition |
A compositional group of igneous rocks indicating the rock is composed almost entirely of light-colored silicates | Granitic composition (Felsic) |
A compositional group of igneous rocks indicating that the rock contains substantial dark silicate minerals and calcium-rich plagioclase feldspar | Basaltic composition (Mafic) |
Igneous activity that occurs at Earth's surface | Extrusive |
Igneous rock that formed below Earth's surface | Intrusive rock |
A body of molten rock found at depth, including any dissolved gases and crystals | Magma |
A broad, gently sloping volcano built from fluid basaltic lavas. Mauna Loa, Hawaii | Shield volcano |
A rather small volcano built primarily of ejected lava fragments that consist mostly of pea- to walnut-size lapilli. Sunset Crater, AZ | Cinder cone volcano |
A volcano composed of both lava flows and pyroclastic material. Mount Rainier, Mount St. Helen | Composite cone volcano (stratovolcanoes) |
Volcanic Landform: Shield Volcanoes, Basalt Plateaus, Cinder Cones Gas Content? | Gas Content = Least (1-2%) |
Volcanic Landform: Composite Cones Gas Content? | Gas Content = Intermediate (3-4%) |
Volcanic Landform: Volcanic Domes, Pyroclastic Flows Gas Content? | Gas Content = Greatest (4-6%) |
Volcanic Landform: Shield Volcanoes, Basalt Plateaus, Cinder Cones Tendency to Form Pyroclastics? | Tendency to Form Pyroclastics = Least |
Volcanic Landform: Shield Volcanoes, Basalt Plateaus, Cinder Cones Viscosity? | Viscosity = Least |
Volcanic Landform: Shield Volcanoes, Basalt Plateaus, Cinder Cones Silica content? | Silica content = Least (~50%) |
Volcanic Landform: Shield Volcanoes, Basalt Plateaus, Cinder Cones Composition? | Composition = Basaltic Magma |
Volcanic Landform: Composite Cones Composition? | Composition = Andesitic Magma |
Volcanic Landform: Composite Cones Silica content? | Silica content = Intermediate (~60%) |
Volcanic Landform: Composite Cones Viscosity? | Viscosity = Intermediate |
Volcanic Landform: Composite Cones Tendency to Form Pyroclastics? | Tendency to Form Pyroclastics = Intermediate |
Volcanic Landform: Volcanic Domes, Pyroclastic Flows Composition? | Composition = Rhyolitic Magma |
Volcanic Landform: Volcanic Domes, Pyroclastic Flows Silica content? | Silica content = Most (~70%) |
Volcanic Landform: Volcanic Domes, Pyroclastic Flows Viscosity? | Viscosity = Greatest |
Volcanic Landform: Volcanic Domes, Pyroclastic Flows Tendency to Form Pyroclastics? | Tendency to Form Pyroclastics = Greatest |
A highly heated mixture, largely of ash and pumice fragments, traveling down the flanks of a volcano or along the surface of the ground. Includes ash, bombs, and blocks | Pyroclastic Flow |
The disintegration and decomposition of rock at or near the surface of Earth | Weathering |
The physical disintegration of rock, resulting in smaller fragments without changing the rock's mineral composition | Mechanical weathering |
The processes by which the internal structure of a mineral is altered by the removal and/or addition of elements. Transformation of rock into one or more new compounds. | Chemical weathering |
Mechanical weathering process examples | Frost Wedging, Salt Crystal Growth, Sheeting, Thermal Expansion, Biological Activity |
Chemical weathering process examples | Dissolution, Oxidation, Hydrolysis, Spheroidal Weathering |
The mechanical breakup of rock caused by the expansion of freezing water in cracks and crevices | Frost Wedging |
___ water evaporates, ___ crystals form & as they gradually grow larger, they weaken rock by pushing apart the surrounding grains or enlarging tiny cracks | Salt Crystal Growth |
A mechanical weathering process characterized by the splitting off of slablike sheets of rock | Sheeting |
A common form of chemical weathering, it is the process of dissolving into a homogeneous solution, as when an acidic solution dissolves limestone. Halite (common salt) readily dissolves in water | Dissolution |
The removal of one or more electrons from an atom or ion. So named because elements commonly combine with ___ | Oxidation |
A chemical weathering process in which minerals are altered by chemically reacting with water and acids | Hydrolysis |
Any weathering process that tends to produce a spherical shape from an initially blocky shape | Spheroidal weathering |
A feature in some sedimentary rocks that forms when wet mud dries out, shrinks and cracks. Associated with tidal flats, shallow lakes, and desert basins | Mud crack |
A sedimentary rock texture consisting of broken fragments of preexisting rock | Clastic texture |
The degree of similarity in particle size in sediment or sedimentary rock | Sorting |
Degree to which the clast's edges and corners are rounded | Angularity |
How close the shape of the clast is to a sphere | Sphericity |
A pattern of cracks that forms during cooling of molten rock to generate columns. five-to seven-sided columns are produced by contraction and fracturing as a lava flow or sill gradually cools | Columnar joints "columnar basalt" |
A tabular-shaped intrusive igneous feature that cuts through the surrounding rock | Dike |
A tabular igneous body that was intruded parallel to the layering of preexisting rock | Sill |
Describing a feature such as an igneous pluton having two dimensions that are much longer than the third. | Tabular (tabula = table) |