interfinger

[in-ter-fing-ger]
verb (used without object) Geology.
  1. (of sedimentary rocks) to change laterally from one type to another in a zone where the two types form interpenetrating wedges.

Origin of interfinger

First recorded in 1970–75; inter- + finger
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018