Clastic rock — A thin section of a clast (sand grain), derived from a basalt score. Vesicles (air bubbles) can be seen throughout the clast. Plane light above, cross polarized light below. Scale box is 0.25 mm Clastic rocks are composed of fragments, or clasts … Wikipedia
rock — rock1 rockless, adj. rocklike, adj. /rok/, n. 1. a large mass of stone forming a hill, cliff, promontory, or the like. 2. Geol. a. mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or considerable… … Universalium
Rock — /rok/, n. a male given name. * * * I In geology, a naturally occurring and coherent aggregate of minerals. The three major classes of rock igneous, sedimentary, and metamorphic are based on the processes that formed them. These three classes are… … Universalium
Rock (geology) — In geology, rock is a naturally occurring aggregate of minerals and/or mineraloids.The Earth s outer solid layer, the ‘lithosphere’, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic. The… … Wikipedia
sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… … Universalium
Sedimentary 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… … Wikipedia
igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary … Universalium
Silurian Period — Interval of geologic time, 443–417 million years ago. The third period of the Paleozoic Era, the Silurian follows the Ordovician Period and precedes the Devonian. It marks the first appearance of land plants and jawed fishes. The continents were… … Universalium
Bend Arch-Fort Worth Basin — Infobox Oil field name = Bend Arch Fort Worth Basin Province region = North Central Texas country = United States coordinates = locblock = offonshore = Onshore operators = Devon Energy, Chesapeake Energy, EOG Resources, XTO Energy, EnCana, Range … Wikipedia
cave — cavelike, adj. /kayv/, n., v., caved, caving. n. 1. a hollow in the earth, esp. one opening more or less horizontally into a hill, mountain, etc. 2. a storage cellar, esp. for wine. 3. Eng. Hist. a secession, or a group of seceders, from a… … Universalium