alloformation

English

Noun

alloformation (plural alloformations)

1. (geology) The fundamental allostratigraphic unit, which may be considered part of an allogroup and may be made up of smaller allomembers; A mappable stratiform body of sedimentary rock that is bounded by discontinuities.
   • 1988, Michael N. Machette, In the Footsteps of G.K. Gilbert, page 86:

     This area is not part of a steep range front with deeply incised stream valleys, so the disconformity between the alloformations does not have the great (tens to more than 100 m) relief that is found elsewhere along the Wasatch front.

   • 1990, Roy R. Lemon, Principles of Stratigraphy, page 520:

     An alloformation may be completely or only partly divided into allomembers, if some useful purpose is served, or it many have no allomembers.

   • 2005, G. Mathias Kondolf, Hervé Piégay, Tools in Fluvial Geomorphology, page 37:

     The concept of alloformations has added useful rigor to the conventional geomorphic tool of mapping and correlating fluvial geomorphic events by the landforms they leave behind.