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.
Introduction Spreading Center magmas Subduction Zone magmas Continental magmas Factors affecting magma generation Formation of granitic magma A new thought...Click here for more on elements and minerals common to the major magma types Click here for more on magma and igneous rocks.ntroduction Spreading Center magmas Subduction Zone magmas Continental magmas Factors affecting magma generation Formation of granitic magma A new thought...