Download A combination of related parts that interact in an

A combination of related parts that interact in an organized fashion; Earth systems include the atmosphere, hydrosphere, biosphere, and solid Earth. Earth’s outer, rigid part, consisting of the upper mantle, oceanic crust, and continental crust. The thick layer between Earth’s crust and core. The interior part of Earth beginning at a depth of 2,900 km that probably consists mostly of iron and nickel. The science concerned with the study of Earth materials (minerals and rocks), surface and internal processes, and Earth history. A naturally occurring, inorganic, crystalline solid that has characteristic physical properties and a narrowly defined chemical composition. A solid aggregate of one or more minerals, as in limestone and granite, or a consolidated aggregate of rock fragments, as in conglomerate, or masses of rocklike materials, such as coal and obsidian. An explanation for some natural phenomenon that has a large body of supporting evidence. To be scientific, a theory must be testable (e.g., plate tectonic theory). A logical, orderly approach that involves gathering data, formulating and testing hypotheses, and proposing theories. A provisional explanation for observations that is subject to continual testing. If well‐supported by evidence, a hypothesis may be called a theory. Earth’s outermost layer; the upper part of the lithosphere that is separated from the mantle by the Moho; divided into continental and oceanic crust. A model for the evolution of the universe in which a dense, hot state was followed by expansion, cooling, and a less‐dense state. A theory for the evolution of the solar system from a rotating cloud of gas. Any of the four innermost planets (Mercury, Venus, Earth, and Mars). They are all small and have high mean densities, indicating that they are composed of rock and metallic elements. Any of the four planets that resemble Jupiter. All are large and have low mean densities, indicating that they are composed mostly of lightweight gases, such as hydrogen and helium, and frozen compounds, such as ammonia and methane The part of the mantle that lies below the lithosphere; it behaves plastically and flows slowly. Molten rock material generated within Earth. An individual segment of the lithosphere that moves over the asthenosphere. The theory holding that large segments of Earth’s outer part (lithospheric plates) move relative to one another. A group of processes through which Earth materials may pass as they are transformed from one major rock type to another. Any rock formed by cooling and crystallization of magma or lava or the consolidation of pyroclastic materials. Any rock composed of sediment, such as limestone and sandstone. Any rock that has been changed from its original condition by heat, pressure, and the chemical activity of fluids, as in marble and slate. The theory holding that all living things are related and that they descended with modification from organisms that lived during the past. The remains or traces of once‐living organisms. A chart arranged so that the designation for the earliest part of geologic time appears at the bottom followed upward by progressively younger time designations. A principle holding that we can interpret past events by understanding present‐day processes, based on the idea that natural processes have always operated in the same way.