Spatial and temporal reasoning techniques in geological modeling

Abstract In building geological models of the crust, spatial and temporal reasoning plays an essential role, providing constraints that narrow down the set of acceptable models. We present here the main results of an analysis of the temporal and spatial reasoning in geological modeling. Using concepts from topology and graph theory, we propose a mathematical model of sedimentary bodies, which captures some of their basic qualitative properties, including the relations among them. We introduce a formal representation of the spatial and temporal constraints that consistent models must satisfy, and present a set of algorithms aimed at: 1) helping the user in focusing attention on the most relevant structural elements, like markers and pinch-outs; 2) validating the spatial and temporal consistency of model hypotheses and diagnosing inconsistencies. These tools have been applied to the problem of building subsurface models from reflection seismic exploration data, as a part of the Horizons research project aimed at the construction of an advanced workstation for seismic interpretation. The design principles and the architecture of the system are also summarised.