Thomas L. Davis Geologist makes geologic maps of the subsurface and surface and 2D & 3D models that integrate these maps. These products assist our clients unravel the structural complexity of their areas of interest and add value to assets, reduce uncertainty, and quantify risk. Clients are most commonly from the resource extraction industry (oil & gas and mining) and geotechnical services when geologic hazards such as hidden earthquake sources such as blind thrusts are a concern. Our maps and models are constructed from various data sets such as oil and gas wells, water wells, seismic reflection and gravity data, remote sensing, and existing geologic mapping and cross sections. We have been making integrated geologic maps, even in remote areas with no previous mapping, for over 30 years in both domestic (USA) and overseas settings.

Our Integrated Mapping Approach

Surface geology alone is insufficient for evaluating the structural complexity of an area. For example, in oil & gas evaluations the resource potential and economic risk of an area cannot be fully determined without subsurface mapping. Similarly, the earthquake hazard and seismic risk of an area cannot be determined by surface geology alone as shown by the damaging and deadly 1983 Coalinga, 1987 Whittier Narrows, and 1994 Northridge earthquakes that occurred along hidden faults. The oil & gas Industry has appreciated for over 100 years the importance of integrated subsurface and surface mapping but this approach in earthquake hazard research and geo-technical evaluations is not that common and existing work show a lack of experience. Surface geologic mapping, while useful, is limited to displaying the 2D intersection of the earth's topography with the earth’s structural framework (a 3D volume). We build integrated 2D & 3D geologic models of the earth’s structural framework that provide a unique, or, at the least, a limited amount of valid solutions.


Most of our products are GIS (Geographical Information System) based and can be exported to a variety of other platforms and presentation formats (visit Downloads for Free, Studies & Data for Sale, and Publications). In-house, we use a variety of programs such as Petra, Kingdom, various GIS platforms such as ArcMAP & MapInfo, and various structural geology programs.


In-house, we store an extensive data base of international and USA geologic maps, cross sections, well data (scanned and .LAS format), and publicly available geophysical data.

Field Trips

We lead customized geologic field trips to the western USA for organizations and companies. Our past professional society trips have been through the AAPG (American Association of Petroleum Geologists), PS-AAPG (Pacific Section- American Association of Petroleum Geologists), and GSA (Geologic Society of America)(visit Downloads for Free\Field Trip Guidebook, and Field Trips and Courses).

Thomas L. Davis PhD, California Professional Geologist #4171, Ventura, California 93001, USA