Intrusive rocks


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Related to Intrusive rocks: Volcanic rocks
(Geol.) rocks which have been forced, while in a plastic or melted state, into the cavities or between the cracks or layers of other rocks. The term is sometimes used as equivalent to plutonic rocks. It is then contrasted with effusive or volcanic rocks.

See also: Intrusive

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Forum's mineral claims cover an approximate 18 km strike length of what is known as the Love Lake Igneous Complex (including the Swan River Complex, Love Lake Pluton and other intrusive rocks).
The eastern segment contains mafic to ultramafic volcanic and intrusive rocks, and is part of the Eastern Goldfields Granite Greenstone Terrane.
The gold mineralisation is associated with altered (biotite-silica) and locally sheared intervals of the intrusive rocks. These new results demonstrate the lateral continuity of the gold mineralisation.
Around Abakaliki town (approximately 30km north of the mineralized area) a number of volcanic and intrusive rocks consisting mainly of pyroclastics form small reliefs corresponding to a heterogeneous group.
Gold-copper mineralization is associated with quartz plus magnetite stockwork zones hosted in potassic altered diorite intrusive rocks.
In Brazil, summit level technique was introduced for the morphologic analyses of Pocos de Caldas alkaline intrusive complex, State of Minas Gerais, in order to examine if the present morphology is originated from a volcanic caldera or differential erosion of felsic alkaline intrusive rocks. The Mendanha alkaline intrusive body, State of Rio de Janeiro, was studied using summit level technique to verify if it is a volcanic edifice with cone and crater or an intrusive massif originated from differential erosion of felsic alkaline rocks (MOTOKI et al., 2008a).
However, it is possible to identify a broad magmatic arc of cordilleran type that was active during the Late Cretaceous-Early Tertiary (Coney and Reynolds, 1977; Atwater, 1989), which produced abundant volcanic and intrusive rocks.
In addition, there are two undeformed, unmetamorphosed, intrusive rocks with U-Pb LA-ICPMS zircon ages of 48.1 +-0.8 Ma and 45.8 +-0.8 Ma.
The lithology of intrusive rocks consists of gabbro, diorite, quartz diorite, granodiorite, biotite granite and leucogranite.
According to the current New Brunswick lexicon of bedrock geology (New Brunswick Department of Natural Resources 2010), the Saint George Plutonic Suite is a contiguous cluster of mainly high-level intrusive rocks comprising (in inferred chronological order from oldest to youngest) the Bocabec Gabbro, Utopia Granite, Welsford,Jake Lee Mountain, and Parks Brook alkali granites, Magaguadavic Granite, John Lee Brook Granite, and Mount Douglas Granite.
He studied ferromagnesian minerals in the basic igneous intrusive rocks in the Wichita Mountains of Oklahoma.