We present an integrated geomagnetic polarity and stratigraphic time scale for the Triassic, Jurassic, and Cretaceous periods of the Mesozoic Era, with age estimates and uncertainty limits for stage boundaries. The time scale uses a suite of 324 radiometric dates, including high‐resolution 40Ar/39Ar age estimates. This framework involves the observed ties between (1) radiometric dates, biozones, and stage boundaries, and (2) between biozones and magnetic reversals on the seafloor and in sediments. Interpolation techniques include maximum likelihood estimation, smoothing cubic spline fitting, and magnetochronology. The age estimates for the 31 stage boundaries (in mega‐annum) with uncertainty (millions of years) to 2 standard deviations, and the duration of the preceding stages (in parentheses) are Maastrichtian/Danian (Cretaceous/‐Cenozoic) is 65.0±0.1 Ma (6.3 m.y.), Campanian/Maastrichtian is 71.3±0.5 Ma (12.2 m.y.), Santonian/Campanian is 83.5±0.5 Ma (2.3 m.y.), Coniacian/Santonian is 85.8±0.5 Ma (3.2 m.y.), Turonian/Coniacian is 89.0±0.5 Ma (4.5 m.y.), Cenomanian/Turonian is 93.5±0.2 Ma (5.4 m.y.), Albian/Cenomanian is 98.9±0.6 Ma (13.3 m.y.), Aptian/Albian is 112.2±1.1 Ma (8.8 m.y.), Barremian/Aptian is 121.0±1.4 Ma (6.0 m.y.), Hauterivian/Barremian is 127.0±1.6 Ma (5.0 m.y.), Valanginian/Hauterivian is 132.0±1.9 Ma (5.0 m.y.), Berriasian/Valanginian is 137.0±2.2 Ma (7.2 m.y.), Tithonian/Berriasian (Jurassic/Cretaceous) is 144.2±2.6 Ma (6.5 m.y.), Kimmeridgian/Tithonian is 150.7±3.0 Ma (3.4 m.y.), Oxfordian/Kimmeridgian is 154.1±3.2 Ma (5.3 m.y.), Callovian/Oxfordian is 159.4±3.6 Ma (5.0 m.y.), Bathonian/Callovian is 164.4±3.8 Ma (4.8 m.y.), Bajocian/Bathonian is 169.2±4.0 Ma (7.3 m.y.), Aalenian/Bajocian is 176.5±4.0 Ma (3.6 m.y.), Toarcian/Aalenian is 180.1±4.0 Ma (9.5 m.y.), Sinemurian/Pliensbachian is 195.3±3.9 Ma (6.6 m.y.), Hettangian/Sinemurian is 201.9±3.9 Ma (3.8 m.y.), Rhaetian/Hettangian (Triassic/Jurassic) is 205.7±4.0 Ma (3.9 m.y.), Norian/Rhaetian is 209.6±4.1 Ma (11.1 m.y.), Carnian/Norian is 220.7±4.4 Ma (6.7 m.y.), Ladinian/Carnian is 227.4±4.5 Ma (6.9 m.y.), Anisian/Ladinian is 234.3±4.6 Ma (7.4 m.y.), Olenekian/Anisian is 241.7±4.7 Ma (3.1 m.y.), Induan/Olenekian is 244.8±4.8 Ma (3.4 m.y.), Tatarian/Induan (Permian/Triassic) is 248.2±4.8 Ma. The uncertainty in the relative duration of each individual stage is much less than the uncertainties on the ages of the stage boundaries.

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A variety of regional geoscience datasets from Nova Scotia have been co-registered and analyzed using a geographic information system (GI$). The datasets include bedrock and surficial geological maps, airborne geophysical survey data, geochemistry of lake-sediment samples, and mineral occurrence data. A number of line features, including structural lineaments, fold axes and formation contacts, have also been digitized. The GI$ uses a quadtree structure, ideally suited to a mixture of polygonal-thematic (e.g., geological maps) and continuous "grey-scale" (e.g., remote sensing, airborne geophysics) raster images. The goal of the study was to create a map showing areas favorable for gold mineralization, based on the distribution of 70 known gold occurrences. Initially, a multi-element geochemical signature was generated using a regression analysis to find the linear combination of geochemical elements that best predict lake catchment basins containing a gold occurrence. A predicted gold occurrence map, based on the geochemistry alone, was produced. A method using Bayes' rule was applied to combine other factors important for gold prediction with the geochemical signature. A unique conditions map shows all those areas where a unique set of overlap between the predictor maps occurs. For each unique condition, an a posteriori probability was calculated, resulting in a map depicting probability of gold mineralization. This map confirms that the major known gold districts coincide with areas of high probability. Several new areas of high potential are indicated by the model, although exploration follow-up has not yet been carried out.