ophiolite
61Abiogenic petroleum origin — is a largely abandoned hypothesis that was proposed as an alternative to theory of biological petroleum origin. It was relatively popular in the past, but it went largely forgotten at the end of the 20th century after it failed to predict the… …
62Peridotite — A peridotite is a dense, coarse grained igneous rock, consisting mostly of the minerals olivine and pyroxene. Peridotite is ultramafic and ultrabasic, as the rock contains less than 45% silica. It is high in magnesium, reflecting the high… …
63Chetco River — Coordinates: 42°02′43″N 124°16′14″W / 42.04528°N 124.27056°W / 42.04528; 124.27056 …
64Eclogite — (pronEng|ˈɛklədʒaɪt) is a coarse grained mafic (basaltic in composition) metamorphic rock. Eclogite is of special interest for at least two reasons. First, it forms at pressures greater than those typical of the crust of the Earth. Second, being… …
65Forearc — A forearc is a depression in the sea floor located between a subduction zone and an associated volcanic arc. It is typically filled with sediments from the adjacent landmass and the island arc in addition to trapped oceanic crustal material. The… …
66Epidosite — (pronEng|ɨˈpɪdəsaɪt) is a highly altered epidote and quartz bearing rock. It is the result of extreme hydrothermal fluid alteration of basalt that occurs below the black smokers within mid oceanic ridge spreading centers. Similar altered rocks… …
67Sapphirine — Indigo blue sapphirine crystal from Ft. Dauphin, Madagascar (size: 2.1 x 1.9 x 1.4 cm) General Category Silicate mineral …
68Chrysoprase — This article is about the mineral. For the fictional character, see Trolls (Discworld). Chrysoprase (Poland) Chrysoprase, chrysophrase or chrysoprasus is a gemstone variety of chalcedony (a cryptocrystalline form of silica) that contains small… …
69Structure of the Earth — Earth cutaway from core to exosphere. Left picture is not to scale. The interior structure of the Earth, similar to the outer, is layered. These layers can be defined by either their chemical or their rheological properties. The Earth has an… …
70Geology of the Himalaya — [ Fig 1: The earth in the Early Permian. At that time, India is part of Gondwana and bordered to the north by the Cimmerian Superterrane. Paleogeographic reconstructions. By Dèzes (1999), based on Stampfli and Borel (2002) and Patriat and Achache …
