A type of unconformity at which sedimentary rocks overlie basement (older intrusive igneous rocks and/or metamorphic rocks).

An type of unconformity in which young sedimentary rocks lie on top of older metamorphic or intrusive igneous rocks.

An unconformity in which stratified rocks rest on unstratified igneous or metamorphic rocks.

An unconformity resulting from deposition of sedimentary strata on massive crystalline rock.

an unconformity developed between igneous or metamorphic rock (below) and sedimentary layers (above)

an unconformity separating bedded rocks above from crystalline igneous and/or metamorphic rocks below. (see unconformity).

an unconformity (gap in time) where the older rock below the nonconformity surface is crystalline igneous or metamorphic. A nonconformity usually represents a large gap in time.

an unconformity in which an erosion surface on plutonic or metamorphic rock has been covered by younger sedimentary or volcanic rock. [AHDOS