The Carboniferous stratigraphy of New Brunswick is described in some detail and the structure is discussed and illustrated by geological maps and cross sections. An attempt is made to record many of the data accumulated by geological surface mapping and by seismic, gravimeter, and magnetometer surveys, and to interpret them in the light of recent wildcat drilling and other subsurface geological information. Particular emphasis is placed on the use of seismic surveying in rationalizing the complex structure of the area and in interpreting the attitude of faults in depth. It is felt that sufficient information is now at hand to provide a clearer geological picture of the area.

A new subdivision of the Pennsylvanian strata of New Brunswick is presented. The time break between the Mississippian and Pennsylvanian is pre-Enrage, coinciding with a major period of deformation. A still older period of deformation is now recognized within the Moncton group; this marks the close of Horton time. Due to lack of subsurface control in the greater part of the Moncton basin and the absence of lithological or paleontological horizon markers generally, it is usually impossible to subdivide the Upper Red Bed series which is mapped as the Moncton group. Accordingly, although the Hillsborough formation is still shown as belonging to the Moncton group, it is definitely recognized as being post-Horton in age and as such is more closely related to the Windsor in time.

Abundant evidences of oil exist and large structures in which oil could accumulate are known to occur; however, wildcat drilling to date has failed to find suitable permeability.