Concretions definition of Concretions in the Free Online Encyclopedia.

Concretions

mineral formations of spherical shape found in sedimentary rock or recent sediments. Grains of minerals, rock debris, shells, fish teeth and bones, and plant remains may serve as centers of concretion. Most prevalent among the diverse forms of concretions are globular shapes and, less frequently, elliptical, disklike, and irregular (grown-together) shapes. In terms of structure, the most common are concentrically layered (conchoidal), coarse-banded, radiate-fibrous (spherulitic), and globular concretions. They usually consist of calcium carbonates (calcite and, less frequently, aragonite), ferric oxides and iron sulfides, calcium phosphates, gypsum, and manganese compounds. In limestone they frequently consist of silicic acid (flint nodules).

Concretions are found in deposits of various geologic systems and in sediments of modern lakes, seas, and oceans. Considerable accumulations of ferromanganese concretions (nearly 10 percent of the entire area of the ocean floor), which are of practical interest, are located on the surface of the floors of the Pacific, Atlantic, and Indian oceans.

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No references found	There, in three or four fathoms of water, between the reefs of Pacou and Vanou, lay anchors, cannons, pigs of lead and iron, embedded in the limy concretions. 20,000 Leagues Under The Sea by Verne, Jules View in context Troubles and other realities took on themselves a meta-physical impalpability, sinking to mere mental phenomena for serene contemplation, and no longer stood as pressing concretions which chafed body and soul. Tess of the d'Urbervilles - A Pure Woman by Hardy, Thomas View in context We here see at the bottom of the cliffs, beds containing sharks' teeth and sea-shells of extinct species, passing above into an indurated marl, and from that into the red clayey earth of the Pampas, with its calcareous concretions and the bones of terrestrial quadrupeds. The Voyage of the Beagle by Darwin, Charles View in context	concrete pipe Concrete Placer concrete planer concrete plank concrete posttensioning Concrete Pump concrete reinforcement concrete retarder concrete saw concrete slab concrete steel concrete syntax concrete thinking concrete vibrating machine concrete vibration concrete vibrator Concrete Work Concrete, Lightweight Aggregate Concrete, The concrete-encased beam concrete-encased electrode concreting paper concretion concretionary concretioning Concretions Concubinage concubine CONCUR concurrence concurrency concurrency control concurrent concurrent access Concurrent C Concurrent C++ Concurrent Clean Concurrent CLU Concurrent Constraint Programming concurrent conversion Concurrent DOS concurrent engineering Concurrent Euclid concurrent heating concurrent infection concurrent input/output concurrent line Concurrent LISP concurrent loads Concurrent Massey Hope concurrent method	concretely concreteness concreteness concreteness concreteness concreteness concretes concretes concretes concretes concretes concreting concreting concreting concreting concreting concreting paper concreting paper concretio concretio cordis concretion concretion concretion concretion Concretional concretionary concretionary concretionary concretionary concretioning Concretions Concretisation concretise concretised concretises concretising concretism concretist concretistic Concretive Concretively concretization concretize concretized concretizes concretizing Concreto Betuminoso Usinado Quente Concreto Preesforzado de Centroamérica Concreture Concrew Concrimination CONCT Concubin Concubin Concubin Concubinacy concubinage concubinage concubinage

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There, in three or four fathoms of water, between the reefs of Pacou and Vanou, lay anchors, cannons, pigs of lead and iron, embedded in the limy concretions.

20,000 Leagues Under The Sea by Verne, Jules View in context

Troubles and other realities took on themselves a meta-physical impalpability, sinking to mere mental phenomena for serene contemplation, and no longer stood as pressing concretions which chafed body and soul.

Tess of the d'Urbervilles - A Pure Woman by Hardy, Thomas View in context

We here see at the bottom of the cliffs, beds containing sharks' teeth and sea-shells of extinct species, passing above into an indurated marl, and from that into the red clayey earth of the Pampas, with its calcareous concretions and the bones of terrestrial quadrupeds.

The Voyage of the Beagle by Darwin, Charles View in context