isobase

plural isobases

1. archaeologyA line drawn on a map or chart connecting places of equal or constant land upheaval or subsidence.

   The southern limit of Wright's zero isobase should intersect the north-west coast of England 125 km further north in the vicinity of the southern shore of Morecambe Bay.

   1978, Sea-level Changes: North-West England During the Flandrian Stage, M. J. Tooley

   2 more examples

   Assuming their zero isobase and assuming also that they have correctly identified the beaches, the Jamieson hypothesis is decidedly not favored by their field observations.

   1920, Bulletin of the Geological Society of America, volume 31

   The isobase map shows the marked spatial variability in elevation of archaeological sites from the Groswater Bay west along Lake Melville to the Goose Bay area, as identified by Fitzhugh (1972).

   1992, Lucille Lewis Johnson, Melanie Stright, Paleoshorelines and Prehistory: An Investigation of Method