COMPILATION OF DIGITAL AND 3D GEOLOGICAL MAPS REQUIRED FOR LAND AND WATER MANAGEMENT IN SOUTHERN MANITOBA, CANADA

Efforts to protect and wisely use groundwater and industrial mineral resources in southern Manitoba have required the development of a new generation of geological map products. Geological maps are being digitized and reconciled with each other, while legends are being made more accessible to a broad range of users, both as a digital version of the unmodified original text, as well as in a categorized, queryable format. For groundwater protection, digital and queryable surficial geological maps, along with associated soil maps, are critical. In addition, for all applications, regional 3D geological models are increasingly in demand as the required data, technology, and protocols to build them become more and more accessible. A pilot 3D model for the 200 km x 230 km Winnipeg area was built using a detailed digital elevation model, bathymetric charts for large lakes, offshore seismic surveys, surficial geological maps, drillhole and seismic information for the Quaternary, and existing models for the Phanerozoic rock units. For the Quaternary, key inputs to the new 3D model were cored holes logged by geologists and geophysical surveys. These high-quality results were extrapolated laterally using drillhole data from provincial databases that include data over 100,000 sites, about half of which are in the pilot area. For the water well database, much effort was required to parse 75,000 unique lithological descriptions as queryable information. The Quaternary stratigraphy of the pilot area was hand-interpreted on 46 large color charts, each depicting all drillhole data, surficial geology, and surface elevation for a 5-km wide swath. The interpretation was captured at predicted stratigraphy points at 5 km spacing, and gridded as 3D surfaces. The model has been used for regional groundwater modeling, and progress is now underway in extending the method over all of southern Manitoba. A key challenge will be reconciling interpretations with those of neighboring jurisdictions. Current activity is seen as a broadening of our reliance, not only from paper maps to digital models, but also from plan view maps, to drillhole databases, to 3D models, to dynamic models such as groundwater flow models. It is clear that user requirements demand that geological survey work rapidly advance as far along this progression as can be managed.