Term
|
Definition
| Very level area of the deep-ocean floor, usually lying at the foot of the continental rise. |
|
|
Term
|
Definition
| A subdivision of mantle situated below the lithosphere. This zone of weak material exists below a depth of about 100 kilometers and in some regions extends as deep as 700 km. The rock within this zone is easily deformed. |
|
|
Term
|
Definition
| The gaseous portion of a planet, the planet's envelope of air. One of the traditional subdivisions of Earth's physical environment |
|
|
Term
|
Definition
| The totality of life forms on earth. |
|
|
Term
|
Definition
| The concept that Earth was shaped by catastrophic events of a short-term nature. |
|
|
Term
|
Definition
| A system that self-contained with regard to matter - that is, no matter enters/leaves. (Energy can enter or leave this type of system). |
|
|
Term
|
Definition
| The portion of the seafloor adjacent to the continents. It may include the continental shelf, continental slope, and continental rise. |
|
|
Term
|
Definition
| The gently sloping surface of at the base of the continental slope. |
|
|
Term
|
Definition
| The gently sloping submerged portion of the continental margin, extending from the shoreline to the continental slope. |
|
|
Term
|
Definition
| The steep gradient that leads to the deep-ocean floor and marks the seaward edge of the continental shelf. |
|
|
Term
|
Definition
| The innermost layer of earth based on composition. It is thought to be largely an iron-nickel alloy with minor amounts of oxygen, silicon, and sulfur. |
|
|
Term
|
Definition
| That part of the continental crust that has attained stability; that is, it has not been affected by significant tectonic activity during the Phanerozoic eon. It consists of the shield and stable platform. |
|
|
Term
|
Definition
| The very thin outermost layer of Earth. |
|
|
Term
|
Definition
| A region of roughly the lowermost 200 km of t he mantle where P-waves experience a sharp decrease in velocity. |
|
|
Term
|
Definition
| The portion of seafloor that lies between the continental margin and the oceanic ridge system. This region comprises almost 30 percent of Earth's surface. |
|
|
Term
|
Definition
| A narrow, elongated depression of the seafloor. |
|
|
Term
|
Definition
| Studies the Earth as a system composed of numerous interacting parts, or subsystems. |
|
|
Term
| Principle of Fossil Succession |
|
Definition
| The law that states that fossil organisms succeed one another in a definite and determinable order, and at any time period can be recognized by its fossil content. |
|
|
Term
|
Definition
| The science that examines Earth, its form and composition, and the changes that it has undergone and is undergoing. |
|
|
Term
|
Definition
| The solid Earth; one of the Earth's four basic spheres. |
|
|
Term
|
Definition
| A major division of geology that deals with the origin of the Earth and its development through time. Usually involves the study of fossils and their sequence in rock beds. |
|
|
Term
|
Definition
| The water portion of our planet; one of the traditional subdivisions of Earth's physical environment. |
|
|
Term
|
Definition
| A tentative explanation that is then tested to determine if it is valid. |
|
|
Term
|
Definition
| Rock formed from the crystallization of magma. |
|
|
Term
|
Definition
| The solid innermost layer of Earth, about 1216 km (754 mi) in radius. |
|
|
Term
|
Definition
| A common boundary where different parts of a system interact. |
|
|
Term
|
Definition
| The rigid outer layer of Earth, including the crust and upper mantle. |
|
|
Term
|
Definition
| The part of the mantel that extends from the core-mantle boundary to a depth of 660 km. Also known as the mesosphere |
|
|
Term
|
Definition
| One of EArth's compositional layers. The solid rocky shell that extends from the base of the crust to a depth of 2900 km. |
|
|
Term
|
Definition
| Rock formed by the alteration of preexisting rock deep within the Earth (but still in the solid state) by heat, pressure, and/or chemically active fluids. |
|
|
Term
|
Definition
| Essentially the same thing as a hypothesis, though less exact. |
|
|
Term
|
Definition
| A model for the origin of the solar system that supposes a rotating nebula of dust and gases that contracted to form the Sun and planets. |
|
|
Term
| Negative Feedback Mechanism |
|
Definition
| As used in climatic change, any effect that is opposite of the initial chance and tends to offset it. |
|
|
Term
| Oceanic (Mid-ocean) Ridge |
|
Definition
| A continuous mountainous ridge on the floor of all the major ocean basins and varying in width from 500 to 5000 km (300-3000 mi). The rifts at the crests of these ridges represent divergent plate boundaries. |
|
|
Term
|
Definition
| A system in which both matter and energy flow into and out of the system. Most natural systems are of this type. |
|
|
Term
|
Definition
| Theory that is held with a very high degree of confidence and is comprehensive in scope. |
|
|
Term
|
Definition
| A major division of geology that examines the materials of Earth and seeks to understand the processes and forces acting beneath and upon Earth's surface. |
|
|
Term
| Positive Feedback Mechanism |
|
Definition
| As used in climatic change, any effect that acts to reinforce the initial change. |
|
|
Term
|
Definition
| Rocks and structures are placed in their proper sequence or order. Only the chronological order of events is determined. |
|
|
Term
|
Definition
| A model that illustrates origin of the three basic rock types and the inter-relatedness of Earth materials and processes. |
|
|
Term
|
Definition
| An isolated volcanic peak that rises a t least 1000 meters (3300 ft.) above the deep-ocean floor. |
|
|
Term
|
Definition
| Rock formed from the weathered products of preexisting rocks that have been transported, deposited, and lithified. |
|
|
Term
|
Definition
| A large, relatively flat expanse of ancient igneous and metamorphic rocks within the craton. |
|
|
Term
|
Definition
| The cloud of interstellar gas and/or dust from which the bodies of our solar system formed. |
|
|
Term
|
Definition
| That part of the craton that is mantled by relatively undeformed sedimentary rocks and underlain by a basement complex of igneous and metamorphic rocks. |
|
|
Term
|
Definition
| The law that states that in any undeformed sequence of sedimentary rocks, each bed is older than the one above and younger than the one below it. |
|
|
Term
|
Definition
| A group of interacting or interdependent parts that form a complex whole. |
|
|
Term
|
Definition
| A well-tested and widely accepted view that explains certain observable facts. |
|
|
Term
|
Definition
| The range of the upper mantle from roughly 410 km to 660 km. It is identified by a sudden increase in density from about 3.5 gm/cm^3 to 3.7 gm/cm^3. |
|
|
Term
|
Definition
| The concept that the processes that have shaped Earth in the geologic past are essentially the same as those operating today. |
|
|
