FY 1997

Is the "Axial Summit Caldera" on the East Pacific Rise really a "graben"?

Chadwick, Jr., W.W.

RIDGE Events, 8(1), January 1997, 8–11 (1997)

The purpose of this short article is to propose the hypothesis that the "axial summit caldera" on the crest of the East Pacific Rise (EPR) is structurally controlled by dike-induced graben formation, rather than by caldera collapse. If correct, then "axial summit graben" would be a more meaningful term than "axial summit caldera." This is more than just an exercise in semantics, since the two names imply different geologic processes of formation and lead to different morphologic and structural interpretations.