= geosyncline, n. Now rare.

A large-scale basin or trough in the earth's crust containing sedimentary and volcanic deposits of great thickness, formerly hypothesized to have…

A geosyncline situated within an older craton or (originally) at the edge of a continental craton.

A linear geosyncline situated between a continental and an oceanic craton, typically comprising a miogeosyncline and an adjacent eugeosyncline.

a geosyncline in which material of volcanic origin predominates.

A geosyncline containing little or no volcanic rock; esp. one situated between a larger, volcanic geosyncline (a eugeosyncline) and an area of the…

= miogeosyncline, n.

= eugeosyncline n. at eugeosynclinal, adj. derivatives.