| Rock Layers |
Article Index for Rock |
Articles about Stratum |
Information AboutRock Layers |
| CATEGORIES ABOUT STRATUM | |
| stratigraphy | |
| methods and principles in archaeology | |
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, Canada . It is made up of thick layers of ocean sediments that were laid down during the Middle Cambrian period and were subsquently pushed up onto land. This formation now covers over half of the province of Nova Scotia and is recorded as being 29,000 feet in thickness in some areas.]] and Shale strata in eastern Tennessee ]] In or Soil with internally consistent characteristics that distinguishes it from contiguous layers. 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 Cliff s, Road cuts, Quarries , and River banks. Individual bands may vary in thickness from a few Millimeter s to a Kilometer or more. Each band represents a specific mode of Deposition -- river Silt , beach Sand , coal Swamp , Sand Dune , Lava bed, etc. Geologist s study rock strata and categorize them by the material in the beds. Each distinct layer is usually assigned a "formation" name 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 Fossil iferous, 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." Groups may be collected into "series." The stratum is the fundamental unit in a Stratigraphic Column and forms the basis of the study of Stratigraphy . SEE ALSO EXTERNAL LINK |
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