Nappe

a large-scale geological structure (tens of kilometres) occurring as a sheet of rock which has been pushed over a fault plane or THRUST at the base. They are formed due to compression, but an alternative mechanism is the sliding due to gravity along a low angle fault, as seen in the Swiss Alps. In many cases, the origin of nappes may be due to a combination of both mechanisms.

Taken from Dictionary of Science

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In geology, a nappe is a large sheetlike body of rock that has been moved more than 2 km (1.2 miles) or 5 km from its original position. Nappes form during continental plate collisions, when folds are sheared so much that they fold back over on themselves and break apart. The resulting structure is a large-scale recumbent fold. The term stems from the French word for tablecloth.

Nappes or nappe belts are a major feature of the European Alps, Carpathians and Balkans. The concept was developed by the French geologists who unraveled the complex tectonic history of the Alps, led by M.A. Bertrand, who identified the feature as nappe de charriage. In Switzerland it was A. Escher von der Linth and M. Lugeon. At the same time, nappe structure was investigated in northwestern Scotland by Ch. Lapworth. The Austroalpine nappes of the eastern Alps consist of a series of three thrust-faulted nappe stacks which overlie the three older Penninic nappes in this very complex system.

Taken from Wikipedia

Parabola

a plane curve traced out by a point moving so that its distance from a fixed point (focus) is equal to its perpendicular distance from a fixed straight line (directrix). It is also the curve made by cutting a cone with a flat plane that is parallel to the side of the cone that slopes. Mirrors with a parabolic shape are used in searchlights and telescopes because incoming parallel rays of light are reflectd onto the focus. This property is used in a telescope, and thus the reverse applies in searchlights.

Taken from Dictionary of Science

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In mathematics, the parabola (pronounced /pəˈræbələ/, from the Greek παραβολή) is a conic section, the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface. Given a point (the focus) and a corresponding line (the directrix) on the plane, the locus of points in that plane that are equidistant from them is a parabola.

The parabola has many important applications, from automobile headlight reflectors to the design of ballistic missiles. They are frequently used in physics, engineering, and many other areas.

Taken from Wikipedia

X-Axis

the "horizontal" axis when constructing and plotting a graph.

Taken from Dictionary of Science

The coordinate surfaces of the Cartesian coordinates (x, y, z). The z-axis is vertical and the x-axis is highlighted in green. Thus, the red plane shows the points with x=1, the blue plane shows the points with z=1, and the yellow plane shows the points with y=-1. The three surfaces intersect at the point P (shown as a black sphere) with the Cartesian coordinates (1, -1, 1).

Taken from Wikipedia