Meaning of eugeosyncline

eu•ge•o•syn•cline

Pronunciation: (y-jē"ō-sing'klīn, -sin'-), [key]
— n. Geol.
  1. a former marine zone, bordering an ocean basin, marked by very thick deposits of sediment in which the products of volcanic activity are associated with clastic sediments.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.