Abstract
This paper presents the algorithm for the automated inference of the stratigraphic sequence and its“Prolog”program, based on Shiono and Wadatsumi's (1988) principle, which formalized the logical process to arrange the order of geological events using the mathematical notation related to the binary relation.
The algorithm is as follows:
(1) Geological bodies observed at outcrops are listed and each body is described as body (a) .
(2) Two types of geological relation are described in terms of the binary relations: on (a, b) when we observe an outcrop showing that a is on b, and upper (a, b) when we obtain a chronological datum suggesting that a is upper (or older) than b.
(3) It is checked whether the relation“on”is antisymmetric.
(4) The relation“on”is extended to the relation“upper”by renexive and transitive closure.
(5) It is checked whether the relation“upper”is antisymmetric. If“upper”is antisymmetric, it is a partia ordering.
(6) It is checked whether every pair of geological bodies is comparable under the relation“upper”. If every pair is comparable, “upper” is a total ordering.
(7) If“upper”is a total ordering, we can arrange geological bodies in a linear sequence: that is, the stratigraphic sequence, using a proper sorting method.
The present study will be useful to construct the fundamental part controlling the computerized-geological mapping system “GEOMAP-CAD” (Wadatsumi et al., 1987) and to enrich its knowledge-base.
