EARTH AS AN EVOLVING PLANETARY SYSTEM Part 8 ppt

... plume volcanism. Except for the Siberian and Emeishan Traps in eastern Asia, all major flood basalt provinces in the last 200 My are associated with the opening a new ocean basin (Coffin and Eldholm, ... Hence, an increase in hydrothermal venting associated with a mantle-plume event could lead to an increase in the biomass, at least in 330 The Supercontinent Cycle and Mantle-Plume Events...

Ngày tải lên: 09/08/2014, 11:20

... (11) 28 6.5 6. Island arc 7 .8 6.2 (6) 6.6 (6) 7.2 (7) 19 6.4 7. Oceanic plateau 8. 0 6.3 (5) 6.5 (10) 6 .8 (10) 25 6.5 8. Inland-sea basin 8. 1 2–5 (7) 6 .8 (15) 22 [25] 6.0 Oceanic 9. Ocean ridge ... continental areas. Back-Arc Basins Back-arc basins are segments of oceanic crust between island arcs (such as the Philippine Sea) or between island arcs and continents (such as the S...

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... volcanic gases 1 78 The Atmosphere and Oceans may have caused average ocean salinity to drop significantly during the Triassic and Jurassic. Evaporite deposition has been sharply episodic, and ... Sun was 25 to 30% less luminous than it is today and that its luminosity has increased with time in an approximately linear manner (Kasting, 1 987 ). The paradox associated with this luminosity c...

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... that many nonvolatile elements such as U, Th, and rare earth elements (REEs), which are Earth s Primitive Crust 267 Major Archean Cratons Stanovoy Aldan Omolon Ladoga Anshan Pilbara Shabani Barberton Sao Francisco Univak Acasta Wyoming Minnesota EnderbyLand Rocks ... production, and Rayleigh number (Chapter 4) decrease with time and that mantle viscosity increases with time, all in accor...

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... separate terranes with unique stratigraphy and deformational histories (Van Kranendonk et al., 2002): an eastern terrane (3.72–2 .85 Ga), a western terrane (3.27–2.92 Ga), and the Kuranna terrane (≤3.29 ... into the mantle, the oldest oceanic basalts should have Nb/U and Nb/Th ratios similar to primitive mantle and these ratios should increase with time. 288 Crustal and Mantle Evolution Ma...

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... distri- butions in ocean-ridge basalts and ophiolites. Primitive mantle values from Sun and McDonough (1 989 ), and other data from Bednarz and Schmincke (1994) and Alabaster et al. (1 982 ). (a) (b) (c) Arc Former ... is an amalga- mation of plates, called by Paul Hoffman the “United Plates of America” (Nelson and DePaolo, 1 985 ; Patchett and Arndt, 1 986 ; Hoffman, 1 988 ). The Archean c...

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... not. Foreland and Hinterland Basins Peripheral foreland and hinterland basins are like retroarc foreland basins in terms of sed- iment provenance and tectonic evolution. Major peripheral foreland and ... alluvial fans also may be deposited in foreland basins. The Himalayas As an example of a young collisional mountain range, none can surpass the High Himalayas. The Himalayan story began s...

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... oceanic and continental areas (Fig. 4. 18) . Some occur on or near ocean ridges, such as Iceland, St. Helena, and Tristan in the Atlantic basin, and others occur near the centers of plates (such as ... the core–mantle boundary region (Hart, 1 988 ). On the other hand, a shallow origin for Dupal is supported by enriched mantle com- ponents in South Atlantic and Indian Ocean NMORB and in is...

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... still occurring on the Earth as ocean-ridge basalts and oceanic plateaus are produced. At least on the Earth and Venus, where substantial heat was available, early crust and lithosphere were rapidly ... distance from the Sun, and the planetary mass all may have Comparative Evolution of the Atmospheres of the Earth, Venus, and Mars 385 Earth accretion, degassing, core formation, mag...

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... solar system, 356– 381 origin of Moon, 396–401 planetary rings, satellites and, 3 68 373 planetary system, Earth as, 1–3 planets, 356–3 68 condensation and accretion of, 388 –396 giant, 3 68 Mars, 3 58 362 Mercury, ... 383 – 385 chemical composition of, 381 – 383 Snowball, 217–2 18 structure of, 3–5 toward convection model for, 1 58 160 uniqueness of, 8 9 Venus, and Mars, 385...

Ngày tải lên: 09/08/2014, 11:20