Suture (geology)

In structural geology, a suture is a joining together along a major fault zone, of separate terranes, tectonic units that have different plate tectonic, metamorphic and paleogeographic histories. The suture is often represented on the surface by an orogen or mountain range. The term was borrowed from surgery where it describes the sewing together of two pieces of tissue, but the sutures of the skull, where separate plates of bone have fused, may be a better metaphor.

Overview

In plate tectonics, sutures are seen as the remains of subduction zones, and the terranes that are joined together are interpreted as fragments of different paleocontinents or tectonic plates.

Outcrops of sutures can vary in width from a few hundred meters to a couple of kilometers. They can be networks of mylonitic shear zones or brittle fault zones, but are usually both. Sutures are usually associated with igneous intrusions and tectonic lenses with varying kinds of lithologies from plutonic rocks to ophiolitic fragments.

Suture

Suture, literally meaning "seam", may refer to:

Surgical suture

Surgical suture (commonly called stitches) is a medical device used to hold body tissues together after an injury or surgery. Application generally involves using a needle with an attached length of thread. A number of different shapes, sizes, and thread materials have been developed over its millennia of history. Surgeons, physicians, dentists, podiatrists, eye doctors, registered nurses and other trained nursing personnel, medics, and clinical pharmacists typically engage in suturing. Surgical knots are used to secure the sutures.

History

Through many millennia, various suture materials were used, debated, and remained largely unchanged. Needles were made of bone or metals such as silver, copper, and aluminium bronze wire. Sutures were made of plant materials (flax, hemp and cotton) or animal material (hair, tendons, arteries, muscle strips and nerves, silk, and catgut).

The earliest reports of surgical suture date to 3000 BC in ancient Egypt, and the oldest known suture is in a mummy from 1100 BC. A detailed description of a wound suture and the suture materials used in it is by the Indian sage and physician Sushruta, written in 500 BC. The Greek father of medicine, Hippocrates, described suture techniques, as did the later Roman Aulus Cornelius Celsus. The 2nd-century Roman physician Galen described gut sutures. In the 10th century the manufacturing process involved harvesting sheep intestines, the so-called catgut suture, and was similar to that of strings for violins, guitar, and tennis racquets.

Suture (joint)

A suture is a type of fibrous joint which only occurs in the skull (or "cranium"). The bones are bound together by Sharpey's fibres. A tiny amount of movement is permitted at sutures, which contributes to the compliance and elasticity of the skull. These joints are synarthroses. It is normal for many of the bones of the skull to remain unfused at birth. The fusion of the skull's bones at birth is known as craniosynostosis. The term "fontanelle" is used to describe the resulting "soft spots". The relative positions of the bones continue to change during the life of the adult (though less rapidly), which can provide useful information in forensics and archaeology. In old age, cranial sutures may ossify (turn to bone) completely. The joints between the teeth and the joint between the mandible and the cranium, the temporomandibular joint, form the only non-sutured joints in the skull.

List of sutures

Most sutures are named for the bones they articulate, but some have special names of their own.

Geology

Geology (from the Greek γῆ, gē, i.e. "earth" and -λoγία, -logia, i.e. "study of, discourse") is an earth science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body (such as the geology of the Moon or Mars).

Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life, and past climates. Geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geology also plays a role in geotechnical engineering and is a major academic discipline.

Geologic materials

The majority of geological data comes from research on solid Earth materials. These typically fall into one of two categories: rock and unconsolidated material.

Country rock (geology)

Country rock is a geological term meaning the rock native to an area. It is similar and in many cases interchangeable with the terms basement and wall rocks.

The term is used to denote the usual strata of a region in relation to the rock which is being discussed or observed.

The following are areas in geology when the term country rock is used;

Geology (journal)

Geology is a publication of the Geological Society of America (GSA). The GSA claims that it is the most widely read scientific journal in the field of earth science. It is published monthly, with each issue containing 20 or more articles, and an annual total of 1166 pages.

One of the goals of the journal is to provide a forum for shorter articles and less focus on pure academic research type articles.

See also

References

External links