Stratum

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.

Characteristics

Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural processes. 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.

Naming

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".

Stratum (album)

Stratum is the second full-length studio album by the Norwegian Christian extreme metal band Drottnar, initially released on October 13, 2012 through Endtime Productions. A single was released for the album, "Lucid Stratum", on November 8, 2011, and the band went on a four-stop tour with Deuteronomium and Pantokrator in Finland from May 2–5, 2013. The album features a highly technical and complex form of extreme metal, and met with a positive reception from critics.

Background and recording

Drottnar formed in Fredrikstad, Norway, in 1996. The band recorded and released two demos, Doom of the Antichrist and A White Realm, both of which were re-mastered and re-released as a compilation, Spiritual Warfare, in 2000. The compilation was described as death/doom and Viking metal. In 2003, the group released an EP, Anamorphosis, and adopted a more minimalist black metal style. A studio album, Welterwerk, followed in 2006, and featured a technical and chaotic sound. Around the time of Welterwerk's release, the band members started wearing early 20th century military regalia in mockery of Nazi and Communist regimes.

Stratum (disambiguation)

Stratum is a geologic formation. Stratum may also refer to:

Telecommunications

Other

See also