
[Latin strātum, a covering, from neuter past participle of sternere, to spread. See stratus.]
stratal stra'tal (strāt'l) adj.USAGE NOTE The standard singular form is stratum; the standard plural is strata (or sometimes stratums), not stratas.
☒ The earth's crust contains stratas of hot, dry rock and natural aquifers—C. Wheater et al., 1990.
| strategy, tactics, straight, strait, straight away | |
| strength, strew, stricken |
In geology, a layer of distinctive deposits with surfaces roughly parallel to those above and below.
A bed of sedimentary rock or earth.
Pl. strata [L.] a sheetlike mass of tissue of fairly uniform thickness; distinct layers making up various tissues or organs, as of the skin, brain, retina.
(n.pl strata) a layer of the epidermis or the epithelium of the oral mucosa.

In geology and related fields, a stratum (plural: strata) is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers. The "stratum" is the fundamental unit in a stratigraphic column and forms the basis of the study of stratigraphy.
When planning civil engineering projects or other large constructions, the strata of the area where the construction takes place is a significant factor in design decisions. For example if a canal is to be built on a route where the strata are not watertight, the canal will have to be lined with some form of waterproof material (usually clay).
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Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural forces. They may extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different colored or differently structured material exposed in cliffs, road cuts, quarries, and river banks. Individual bands may vary in thickness from a few millimeters to a kilometer or more. Each band represents a specific mode of deposition: river silt, beach sand, coal swamp, sand dune, lava bed, etc. it also is very important
Geologists study rock strata and categorize them by the material of beds. Each distinct layer is typically assigned to the name of sheet, usually based on a town, river, mountain, or region where the formation is exposed and available for study. For example, the Burgess Shale is a thick exposure of dark, occasionally fossiliferous, shale exposed high in the Canadian Rockies near Burgess Pass. Slight distinctions in material in a formation may be described as "members" (or sometimes "beds"). Formations are collected into "groups" while groups may be collected into "supergroups".
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Français (French)
n. - (Géol) strate, (Biol) couche, couche (sociale)
Deutsch (German)
n. - Schicht, Stratum
Ελληνική (Greek)
n. - στρώμα, διάστρωση, (γεωλ.) πέτρωμα
Italiano (Italian)
strato, falda
Português (Portuguese)
n. - camada (f)
Русский (Russian)
пласт, слой, уровень, страта
Español (Spanish)
n. - capa, estrato
Svenska (Swedish)
n. - skikt, lager, stratum
中文(简体)(Chinese (Simplified))
层, 组织层, 地层, 社会阶层
中文(繁體)(Chinese (Traditional))
n. - 層, 組織層, 地層, 社會階層
한국어 (Korean)
n. - 지층, (조직의) 층, 계층
日本語 (Japanese)
n. - 岩層, 地層, 階層
العربيه (Arabic)
(الاسم) طبقه (صخور), طور (تاريخ أو نمو)
עברית (Hebrew)
n. - שכבה, רובד, מעמד חברתי
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