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Summary: FIGURE 1: The dome of St. Peter's Basilica. The author suggests that
domes, cathedrals and plates are held together by the St. Peter
Principle.
LARGE IGNEOUS PROVINCES AND THE LITHOSPHERE
Don L. Anderson
Seismological Laboratory
Caltech
Pasadena, Ca., USA 91125
ABSTRACT
Tectonic plates stay together for a reason; they are strong because they are
held together by lateral compression; a cathedral without buttresses to keep
its rocks under compression is ex cathedra. Plates serve to keep magma in
the mantle. Incipient plate boundaries and LIPs form where the lithosphere
is extending. New rifts often experience a burst of magmatism, suggesting a
fertile shallow mantle. Locations of rifts are controlled by lithospheric
conditions, and the volumes of magmas by mantle fertility, ponding, and
focusing. Recycled materials melt because of low melting temperatures and
the large heat bath provided by the mantle itself.
(keywords; LIPs, plumes, hotspots, lithosphere, eclogite)
INTRODUCTION
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