A Sedimentary Strata Modeling Method with Precisely Constrained Stratigraphic Boundaries from Geological Maps

Research Purposes The demand for three-dimensional geological models is increasing in fields such as underground resource exploration and engineering design. Traditional modeling methods ignore the spatial constraints of the geological map when calculating stratum boundaries, treating missing strata as zero-thickness and then interpolating the stratum boundaries, or delineating pinch-out boundaries based on the midline between boreholes with and without strata. These methods often suffer from reduced accuracy due to factors such as data inhomogeneity and complex geological conditions. Therefore, this paper proposes a method for constructing three-dimensional geological models that accurately constrains stratum boundaries using the geological map, achieving deep integration of geological maps with borehole and profile data. Research Methods This method constructs a topological analytical model based on the topological relationships between strata in the geological map and the relationship between the age of strata. It automatically extracts surface stratum boundaries to accurately constrain surface planar partitions. For unexposed areas without geological map constraints, the method uses borehole layer thickness constraints and incorporates the influence of adjacent strata to accurately calculate the pinch-out locations. The surface boundary, pinch-out line, and modeling boundary are integrated into a ternary partitioning structure to automatically track stratum boundaries. Finally, a seamless three-dimensional geological volume is constructed using stratum boundaries as hard constraints through interpolation. Research Results This paper conducted a method experiment in the Gedian Economic and Technological Development Zone of Ezhou City. Using geological maps, boreholes, profiles, and DEM data, we generated optimized stratigraphic boundary constraints. A three-dimensional geological model of the region was constructed and compared with traditional modeling algorithms. Conclusion The results demonstrate that this method can calculate stratigraphic boundaries that better align with the actual distribution of strata, constructing a three-dimensional geological model that is more consistent with the actual strata. This method overcomes the bottlenecks of low geological map utilization and irrational pinch-out calculations in traditional modeling.