In 1968 the average salary of men teachers in maintained schools in England and Wales was Â£1,646. I estimate that the last two pay settlements have raised this figure to about Â£1,880. The comparable figure at 31st March, 1963, was Â£1,244.
Two main tectonic structures are spreading centers and subduction zones. Spreading centers occur at the boundary between two plates that are moving apart, called divergent plate boundaries. Here the plate motion opens a gap between the plates and magma from the mantle rises up through it.
(plural transition zones) Any of several physical zones in which the properties, or the behaviour of something undergoes a radical change (physics) The stage in the flow or a fluid during which it changes from laminar to turbulent. (geology) The region between the upper and lower mantle characterized by a rapid increase in density.