Abstract
This paper treats of engineerisg geological description on distribution and relationship of geologic units. A concept of “foreseeability” is introduced. This is defined to the extent of predictive certainty around a point or a line of examination.
From the viewpoint “foreseeability”, necessity of which the pattern of distribution of geologic units is classified rises up. The classification proposed is as follows.
A. Syngenetic structures
A-1 Homogeneous body
A-2 Layered body
a. well continued
b. poorly continued
A-3 Heterogeneous body
a. chaotic (block-in-matrix)
b. heterogeneity of grain size or composition
B. Postgenetic structures
B-1 Deformation of geologic body
a. fault
b. folding
B-2 Relationship among geologic units
a. unconformity
b. fluidal intrusion or injection
The classification enables us to describe the controlling factors of the foreseeability and to evaluate the degree of foreseeability.
