Geology Vocabulary 1.0

asthenosphere

the layer of the mantle where rocks are relatively ductile and are easily deformed

atmosphere

the mixture of gases, predominantly nitrogen, oxygen, carbon dioxide, and water vapor that surrounds the Earth

catastrophism

the concept that all of earth’s major features, such as mountains, valleys, and oceans, have been produced by a few great catastrophic events

biosphere

the totality of Earth’s organisms and, in addition, organic matter that has not completely decomposed

closed system

any system with a boundary that allows the passage in or out of energy but not matter

continental crust

the part of Earth’s crust that comprises the continents

core

the spherical mass, largely metallic iron, at the center of the Earth

Crust

the outermost and thinnest of Earth’s compositional layers, which consists of rocky matter that is less dense than the rocks of the mantle below

earth system

the assemblage of all of Earth’s parts and the relationship between them

erosion

the complex group of related processes by which rock is broken down physically and chemically and the products are moved

geologists

scientists who study earth

geology

the science of our planet

geosphere

the solid portion of earth

gradualism

geologic processes, when given enough time, can greatly alter the landscape of the Earth

historical geology

study of the chronology of earth’s past events, both physical and biological

hydrologic cycle

the day to day and long-term cycle changes in the hydrosphere

igneous rock

rock formed by the cooling and consolidation of magma

inner core

the center, solid portion of earth’s core

isolated system

any system that has a boundary that prevents the passage in or out of energy and matter

law of original horizontality

water laid sediments are deposited in strata that are horizontal, or nearly horizontal, and parallel, or nearly parallel to the earth’s surface

lithosphere

the outer 100km of solid earth where rocks are harder and more rigid than those in the plastic asthenosphere

magma

molten rock

mantle

the thick shell of dense, rocky matter that surrounds the core

metamorphic rock

rock whose original compounds or textures, or both, have been transformed to new compounds and new textures by reactions in the solid state as a result of changes in temp and pressure

oceanic crust

the crust beneath the oceans

open system

any system that has a boundary that allows the passage in or out of both energy and matter

outer core

the outer portion of earth’s core, which is molten

physical geology

the study of the processes that operate at or beneath the surface of earth, and the materials on which these operate

plate tectonics theory

grand unifying theory of geology saying that earth’s outermost 100km “eggshell” is cracked, composed, of about a dozen pieces, which float on the hot, deformable asthenosphere, moving ponderously in various directions, spreading apart, slowly coliding and grinding past one

principle of uniformitarianism

the same external and internal processes we recognize today have been operating unchanged, though at different rates, throughout most of earth’s surface

regolith

the irregular blanket of loose, noncemented rock particles that cover earth’s surface

rock

any naturally formed, nonliving firm and coherent aggregate mass of mineral matter that constitutes part of a planet

rock cycle

the cyclic movement of rock material, in the course of the which rock is created, destroyed, and altered through the operation of internal and external earth processes

sediment

regolith that has been tansported by any of the external processes

sedimentary rock

any rock formed by chemical precipitation or by sedimentation and comenotation of mineral grains transported to a site of deposition by water, wind, ice, or gravity

solar system

the sun and the group of objects in orbit around it

tectonics

the study of movement and deformation of the lithosphere

tectonic cycle

a model that describes the movement and interactions of lithosphere plates, the internal processes that drive plate motion, and the types of rock formations that develop as a result of tectonic movement and interactions