Search results
Results from the WOW.Com Content Network
The constant circulation of material in the forearc region (accretionary prism, forearc basin and trench) generates a mixture of igneous, metamorphic and sedimentary sequences. In general, there is an increase in metamorphic grade from trench to arc where highest grade (blueschist to eclogite) is structurally uplifted (in the prisms) compared ...
A foreland basin is a structural basin that develops adjacent and parallel to a mountain belt. Foreland basins form because the immense mass created by crustal thickening associated with the evolution of a mountain belt causes the lithosphere to bend, by a process known as lithospheric flexure.
Schematic diagram of the California continental margin during the Cretaceous, showing the deposition of the Great Valley Sequence in a forearc basin between the Franciscan accretionary wedge and the volcanic arc of the Sierra Nevada: Mentawai Strait (aka Bengkulu-Mantawai forearc basin) [48] Magdalena Shelf [49] Nias Basin; Strait of Georgia ...
An older assumption that backstops of accretionary wedges dip back toward the arc, and that accreted material is emplaced below such backstops, is contradicted by observations from many active forearcs that indicate (1) backthrusting is common, (2) forearc basins are nearly ubiquitous associates of accretionary wedges, and (3) forearc basement ...
Tectonic subsidence is the sinking of the Earth's crust on a large scale, relative to crustal-scale features or the geoid. [1] The movement of crustal plates and accommodation spaces produced by faulting [2] brought about subsidence on a large scale in a variety of environments, including passive margins, aulacogens, fore-arc basins, foreland basins, intercontinental basins and pull-apart basins.
Forearc, active arc, and back arc are expressed differently on either side of these boundaries (see figure below). The forearc is that part of the arc system between the trench and the magmatic front of the arc and includes uplifted sectors of the forearc situated near the magmatic front, sometimes called the ‘frontal arc’.
Forebulge associated with the formation of these basins is most commonly a result of convergent collision. [2] Foreland basins can occur in convergent subduction, but this is rare. [2] These basins are linked to fold-thrust belts, which are divided into three main types: collisional (peripheral), retroarc, and retreating collisional subduction. [4]
The Nias Basin (also known as the West Sumatra or Sibolga Basin) is a forearc basin located off the western coast of Sumatra, Indonesia, in the Indian Ocean. The name is derived from the island that bounds its western edge, the island of Nias .