crust over
81Oceanic trench — Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric scale long but narrow topographic depressions of the sea floor. They are also the… …
82Asia — /ay zheuh, ay sheuh/, n. a continent bounded by Europe and the Arctic, Pacific, and Indian oceans. 2,896,700,000; ab. 16,000,000 sq. mi. (41,440,000 sq. km). * * * I Largest continent on Earth. It is bounded by the Arctic Ocean, the Pacific Ocean …
83South America — South American. a continent in the S part of the Western Hemisphere. 271,000,000; ab. 6,900,000 sq. mi. (17,871,000 sq. km). * * * Continent, Western Hemisphere. The world s fourth largest continent, it is bounded by the Caribbean Sea to the… …
84Igneous rock — Geologic provinces of the world (USGS)   Shield …
85Moon — This article is about Earth s Moon. For moons in general, see Natural satellite. For other uses, see Moon (disambiguation) …
86Passive margin — A passive margin is the transition between oceanic and continental crust which is not an active plate margin. It is constructed by sedimentation above an ancient rift, now marked by transitional crust. Continental rifting creates new ocean basins …
87Venus — /vee neuhs/, n., pl. Venuses for 2. 1. an ancient Italian goddess of gardens and spring, identified by the Romans with Aphrodite as the goddess of love and beauty. 2. an exceptionally beautiful woman. 3. (sometimes l.c.) Archaeol. a statuette of… …
88Geology of the Alps — The Alps form a part of a Tertiary orogenic belt of mountain chains, called the Alpide belt, that stretches through southern Europe and Asia from the Atlantic all the way to the Himalayas. This belt of mountain chains was formed during the Alpine …
89Expanding Earth theory — The Expanding Earth theory is an attempt to explain the position and movement of continents (continental drift) on the surface of the Earth. The expanded earth theory (and plate tectonics) incorporates the appearance of new crustal material at… …
90hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
