- rare of, relating to, or consisting of igneous rock, esp a basalt
C19: from trap ³
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for trappean
Such masses are termed trappean agglomerate and trappean breccia.
We first crossed more hills of the trappean conglomerate on which grew ironbark eucalypti and box.
We this day crossed several fine running streams and forests of box and bluegum growing on ridges of trappean conglomerate.
What is the difference between trappean breccia and trappean conglomerate?
They never repose on the volcanic or trappean formations, nor on strata containing organic remains.A Manual of Elementary Geology