English: The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which float on the fluid-like (visco-elastic solid) asthenosphere. The relative fluidity of the asthenosphere allows the tectonic plates to undergo motion in different directions. This map shows 15 of the largest plates.

Earth's tectonic evolution over time from a molten state at 4.5 Ga, to a single-plate lithosphere, to modern plate tectonics sometime between 3.2 Ga and 1.0 Ga Heat flow and tectonic plates [ edit ] Controversy over the exact nature of mantle convection makes the linked evolution of Earth's heat budget and the dynamics and structure of the ...

Formal theory. Formally, a string is a finite, ordered sequence of characters such as letters, digits or spaces. The empty string is the special case where the sequence has length zero, so there are no symbols in the string.

The Mesozoic Era (/ ˌ m ɛ z ə ˈ z oʊ. ɪ k,-z oʊ-, ˌ m ɛ s-, ˌ m iː z-, ˌ m iː. s-/ mez-ə-ZOH-ik, mez-oh-, mess-, mee-z-, mee-s-), also called the Age of Reptiles and the Age of Conifers, is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods.It is characterized by the dominance of archosaurian ...