Platform (geology)

In geology, a platform is a continental area covered by relatively flat or gently tilted, mainly sedimentary strata, which overlie a basement of consolidated igneous or metamorphic rocks of an earlier deformation. Platforms, shields and the basement rocks together constitute cratons. Platform sediments can be classified into the following groups: a "protoplatform" of memtamorphosed sediments at the bottom, a "quasiplatform" of slightly deformed sediments, a "cataplatform", and a "orthoplatform" at the top. The Mesoproterozoic Jotnian sediments of the Baltic area are examples of a "quasiplatform". The post-Ordovician rocks of the South American Platform are examples of an orthoplatform.

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Platform

Platform may refer to:

Technology

Physical objects and features

Politics

Platform (art group)

Platform London is an interdisciplinary London-based art and campaigning collective founded in 1983 that creates projects with social justice and environmental justice themes. Platform describes itself as "bringing together environmentalists, artists, human rights campaigners, educationalists and community activists to create innovative projects driven by the need for social and environmental justice. This interdisciplinary approach combines the transformatory power of art with the tangible goals of campaigning, the rigour of in-depth research with the vision to promote alternative futures."

A 1992 project by Platform sparked a local campaign to dig up the River Effra in London, England.

Their ongoing research into the political economy of oil is called the Unraveling the Carbon Web. Platform has written several books tracking the oil industry, including The Oil Road: Journeys from the Caspian Sea to the City of London published by Verso Books in 2013 and The Next Gulf: Britain, the USA and the politics of oil in the Gulf of Guinea published in 2005 by Constable & Robinson. Some Common Concerns - Imagining BP’s Azerbaijan-Georgia-Turkey Pipelines was released in October 2002.

Theatre platform

In theatre, a platform (also referred to as a riser or rostrum) is a stationary, standard flat walking surface for actors to perform on. Typically, they are built to be assembled modularly. They are often used to provide varying levels, to make a show more visually interesting. They are also used to separate areas on stage, and as seating bleachers. This is in contrast to scenery wagons, which are mobile platforms that are supported by casters instead of feet.

Construction

Platforms are composed of a frame, a lid, and legs.

Lids

Lids are typically made from a sheet of plywood, although oriented strand board is also sometimes used. Sometimes another layer is added on top of the plywood. Hardboard is sometimes used as an easily replaceable and sturdy cover. Homasote is sometimes used because it is quiet and more comfortable to walk on. Occasionally, a layer of muslin is added on top of these materials, as it takes paint better than other options.

Framing

Framing is most commonly made of nominally 2"x4" lumber or rectangular steel tubing, oriented so that its longer dimension is vertical, perpendicular to the lid. Framing is usually arranged to be at or near every edge of the lid. In addition, intermediate members (sometimes called toggles) are added. Common rules of thumb dictate that the lid should not overhang the framing by more than three inches, and that internal framing should be two feet or less apart.

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.