Sill (geology)

src: i.ytimg.com

In geology, sill is a tabular sheet intrusion that has infiltrated between layers of older sedimentary rock, volcanic lava layer or tuff, or along the direction of foliation in metamorphic rocks. A sill is the corresponding intrusive interrupt , which means that the sill does not cut in the pre-existing rock bed. Stacking the jambs builds complex and large magma chambers on high magma flux. In contrast, the embankment is a discordant intrusive intercept, which cuts off older stones. Cages are fed by embankments, except in unusual locations where they form in beds that are almost vertically attached directly to the source of the magma. Rocks must be brittle and fracture to create planes as long as the magma disrupts the body of the mother rock, whether this occurs along the pre-existing plane between the sedimentary bed or the volcano or the weakening of the plane associated with foliasi in metamorphic rocks. These planes or attenuated areas allow the intrusion of thin magma sheets such as aligning existing beds, fracture zones accordingly, or foliation.

Parallel bed frame (lining) and foliation in the surrounding country rocks. They can initially be superimposed in a horizontal orientation, although tectonic processes may cause the next horizontal friction rotation to be near vertical orientation. The frame can be confusing with a compressed lava flow; However, there are some differences between the two. The intrus beam will show partial melting and incorporation of the surrounding country's stones. On both contact surfaces of the state rocks where the jamb has been infiltrated, warming evidence will be observed (contact metamorphosis). The lava flow will show this proof only on the down side of the stream. In addition, lava flows will usually show evidence of vesicles (bubbles) in which gases escape into the atmosphere. Since sills generally form at shallow depths (up to many kilometers) below the surface, rock pressure on top prevents this from happening much, if at all. Lava flows will also usually show weathering evidence on the top surface, while the frame, if still covered by state rock, is usually not.

Video Sill (geology)

Related ore deposits

Certain layered disorders are various thresholds that often contain important ore deposits. Precambrian examples include the Bushveld, Insizwa and Great Dyke complexes in southern Africa, the intrusive Duluth complex in the Superior District, and the Stillwater frozen compound in the United States. Examples of fenerozoic are usually smaller and include the peridotite complex RÃÆ' ofm from Scotland and the frozen Skaergaard complex of eastern Greenland. This disorder often contains concentrations of gold, platinum, chromium and other rare elements.

Maps Sill (geology)

Transgressive pouch

Regardless of their concordant nature, many large sills alter the stratigraphic level in the intruded sequence, with each corresponding portion of the intrusion connected by a relatively short embankment-like segment. These frames are known as transgressive , for example including Whin Sill and sills in the Karoo basin. The geometry of the large threshold complex in the sedimentary basin becomes more apparent with the availability of 3D seismic reflection data. The data shows that many sills have a whole plate shape and many others are at least partially transgressive.

src: all-geo.org

See also

• Water threshold
• Batholith
• Embankment
• Laccolith
• Intrusion sheet
• Swarm Sill
• Stock

src: i.pinimg.com

References

Source of the article : Wikipedia