alloformation

plural alloformations

1. geographyThe 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.

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

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

   2 more examples

   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.

   1988, Michael N. Machette, In the Footsteps of G.K. Gilbert, page 86

   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.

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