dicyclic (di-cy'-clic). (a) Said of a crinoid having two circlets of plates proximal to the radial plates or (in some crinoids that lack radial plates) proximal to the oral plates. (b) Said of the apical system of an echinoid in which ocular and genital plates are arranged in two concentric circles, the genital plates alone in contact with the periproctal margin. Cf: monocyclic.

tectonic map

tectonic map . A map that portrays the architecture of the outer part of the Earth. It is similar to a structure-contour map, which primarily shows dipping strata, folds, faults, and the like, but the tectonic map also presents some indication of the ages and kinds of rocks from which the structures were made, as well as their historical development. Cf: paleotectonic map.

indicated mineral resource

indicated mineral resource . That part of a mineral resource for which tonnage, densities, shape, physical characteristics, grade, and mineral content can be estimated with a reasonable level of confidence. It is indicated by information that is too widely or inappropriately spaced to confirm geological and/or grade continuity but is spaced closely enough for continuity to be assumed (JORC, 1999). Cf: inferred mineral resource; measured mineral resource.


orbitoid (or'-bi-toid). Any foraminifer belonging to the superfamily Orbitoidacea, characterized by large discoidal saddle-shaped or stellate tests with walls composed of radially arranged calcite crystals and with bilamellid septa. Range, Cretaceous to Holocene.


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