biogenic sedimentation
1Biogenic silica — (BSi) is the equivalent to the terms opal, biogenic opal, and amorphous opaline silica. BSi is essential to many plants and animals. Chemically, BSi is hydrated silica (SiO2• n H2O).Diatoms in both fresh and salt water extract silica from the… …
2Contourite — A contourite is a sedimentary deposit produced by thermohaline induced deepwater bottom currents and may be influenced by wind or tidal forces.[1][2] Most contourites are formed in continental rise to lower slope settings, although they may occur …
3natural gas — a combustible mixture of gaseous hydrocarbons that accumulates in porous sedimentary rocks, esp. those yielding petroleum, consisting usually of over 80 percent methane together with minor amounts of ethane, propane, butane, nitrogen, and,… …
4Sedimentary rock — Middle Triassic marginal marine sequence of siltstones (below) and limestones (above), Virgin Formation, southwestern Utah, USA Sedimentary rock are types of rock that are formed by the deposition of material at the Earth s surface and within… …
5sedimentary facies — Different, but contemporaneous and juxtaposed, sedimentary rocks. Terrigenous facies are accumulations of particles eroded from older rocks and transported to the depositional site. Biogenic facies are accumulations of whole or fragmented shells… …
6Passive 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 …
7global warming — an increase in the earth s average atmospheric temperature that causes corresponding changes in climate and that may result from the greenhouse effect. [1975 80] * * * Potential increase in global average surface temperatures resulting from… …
8Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
9Methanogen — Methanopyrus kandleri Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are classified as archaea, a group quite distinct from bacteria. They are common in wetlands, where they are responsible …
10lake — lake1 /layk/, n. 1. a body of fresh or salt water of considerable size, surrounded by land. 2. any similar body or pool of other liquid, as oil. 3. (go) jump in the lake, (used as an exclamation of dismissal or impatience.) [bef. 1000; ME lak(e) …
