Although a complete section of oceanic crust has not yet been drilled, geologists have several pieces of evidence that help them understand the ocean floor. Estimations of composition are based on ana ...
Mid-ocean ridges are geologically active, with new magma constantly emerging onto the ocean floor and into the crust at and near rifts along the ridge axes. The crystallized magma forms new crust of b ...
The South American Plate is a tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the Mid-Atlantic Ridge.The east ...
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and surrounding ocean, and extends northwest to include the Indian subcontinent and adjacent waters. It was ...
The Antarctic Plate is a tectonic plate containing the continent of Antarctica and extending outward under the surrounding oceans. The Antarctic Plate is bounded almost entirely by extensional mid-oce ...
The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indi ...
A few hotspots are thought to exist below the North American Plate. The most notable hotspots are the Yellowstone (Wyoming), Raton (New Mexico), and Anahim (British Columbia) hotspots. These are thoug ...
The westerly side is a divergent boundary with the North American Plate to the north and the South American Plate to the south forming the central and southern part of the Mid-Atlantic Ridge. The Afri ...
The Pacific Plate contains an interior hot spot forming the Hawaiian Islands.Hillis and Müller are reported to consider the Bird's Head Plate to be moving in unison with the Pacific Plate. Bird consi ...
Subduction zones are sites of convective downwelling of Earth's lithosphere (the crust plus the top non-convecting portion of the upper mantle). Subduction zones exist at convergent plate boundaries w ...
There are about 50,000 km (31,000 mi) of convergent plate margins, mostly around the Pacific Ocean—the reason for the reference “Pacific-type” margin—but they are also in the eastern Indian Ocean, ...
See also: Subduction, Plate tectonics and Continental collisionSubduction of an oceanic plate by a continental plate to form a noncollisional orogen. (example: the Andes)Continental collision of two c ...
John Tuzo Wilson recognized that the offsets of oceanic ridges by faults do not follow the classical pattern of an offset fence or geological marker in Reid’s rebound theory of faulting, from which t ...
At divergent boundaries, two plates move apart from each other and the space that this creates is filled with new crustal material sourced from molten magma that forms below. The origin of new diverge ...
The nature of a convergent boundary depends on the type of plates that are colliding. Where a dense oceanic plate collides with a less-dense continental plate, the oceanic plate is typically thrust un ...
