fine-grained sediment
41Oil shale geology — Main article: Oil shale Outcrop of Ordovician kukersite oil shale, northern Estonia. Oil shale geology is a branch of geologic sciences which studies the formation and composition of …
42metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… …
43mineral deposit — Introduction aggregate of a mineral in an unusually high concentration. About half of the known chemical elements (chemical element) possess some metallic (metal) properties. The term metal, however, is reserved for those chemical… …
44petroleum — petroleous, adj. /peuh troh lee euhm/, n. an oily, thick, flammable, usually dark colored liquid that is a form of bitumen or a mixture of various hydrocarbons, occurring naturally in various parts of the world and commonly obtained by drilling:… …
45Geology of the Grand Teton area — The geology of the Grand Teton area consists of some of the oldest rocks and one of the youngest mountain ranges in North America. The Teton Range, mostly located in Grand Teton National Park, started to grow some 9 million years ago. An older… …
46Precambrian time — Interval of geologic time from с 3. 8 billion years ago, the age of the oldest known rocks, to 544 million years ago, the beginning of the Cambrian Period. This interval represents more than 80% of the geologic record and thus provides important… …
47quaternary — /kwot euhr ner ee, kweuh terr neuh ree/, adj., n., pl. quaternaries. adj. 1. consisting of four. 2. arranged in fours. 3. (cap.) Geol. noting or pertaining to the present period of earth history, forming the latter part of the Cenozoic Era,… …
48dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …
49permafrost — /perr meuh frawst , frost /, n. (in arctic or subarctic regions) perennially frozen subsoil. Also called pergelisol. [1943; PERMA(NENT) + FROST] * * * Perennially frozen earth, with a temperature below 32 °F (0 °C) continuously for two years or… …
50Petrography — is that branch of petrology which focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. Petrographic… …
