middellaag

Middellaag is a Dutch term meaning the middle layer of a system that is organized in strata or layers. It is used as a generic label for the layer that lies between an upper layer and a lower layer, without prescribing a specific nature or composition. The exact meaning depends on the disciplinary context.

In geology and soil science, middellaag can refer to the middle stratum within a sequence of layers, for example the layer between the upper soil horizon and deeper layers. In such contexts the term is often used descriptively when a distinct middle layer is present but not assigned a precise designation. In atmospheric science, the word may appear in more informal descriptions to indicate the middle portion of the atmosphere; in technical writing, more specific terms such as stratosphere or mesosphere are preferred to denote the exact layer.

In materials science and engineering, middellaag is used to describe the middle layer in multilayer coatings, laminates, or composite materials, where each layer has different properties and functions. In social and economic analyses, the term can denote a middle socioeconomic stratum that lies between upper and lower segments of a population.

Because middellaag is a generic, cross-disciplinary label, its precise meaning varies with context. It serves as a convenient shorthand when a clear, field-specific term is not being used or when a middle layer is discussed in broad terms. See also layering and stratification.