Fiery Edges

T

he thousand words in the Tharpe-Heezen map
of the seafloor argue for jigsaw crust;
a tattered softball, pieces of skin wrapped
and Frankenstein-stitched where the ridges thrust
up, or sometimes overlap in trenches
cut during many an inning out back,
a global picture of fiery edges:
where orange magma bubbles fade to black
basalt mounds when converging plates buckle
or subduct back into melt, underground;
or rifts cause continents to drift around —
the boundaries dynamic, in tussle.
       Mountains rise and fall; oceans spread, recede;
       volcanoes, earthquakes, and geysers:     repeat.

*[ WSB ].