'Transition rocks' definitions:

Definition of 'Transition rocks'

From: GCIDE

Transition \Tran*si"tion\, n. [L. transitio: cf. F. transition. See Transient.]
1. Passage from one place or state to another; charge; as, the transition of the weather from hot to cold. [1913 Webster]
There is no death, what seems so is transition. --Longfellow. [1913 Webster]
2. (Mus.) A direct or indirect passing from one key to another; a modulation. [1913 Webster]
3. (Rhet.) A passing from one subject to another. [1913 Webster]
[He] with transition sweet, new speech resumes. --Milton. [1913 Webster]
4. (Biol.) Change from one form to another. [1913 Webster]
Note: This word is sometimes pronounced tran*sish"un; but according to Walker, Smart, and most other authorities, the customary and preferable pronunciation is tran*sizh"un, although this latter mode violates analogy. Other authorities say tran*zish"un. [1913 Webster]
Transition rocks (Geol.), a term formerly applied to the lowest uncrystalline stratified rocks (graywacke) supposed to contain no fossils, and so called because thought to have been formed when the earth was passing from an uninhabitable to a habitable state. [1913 Webster]