Northern Resources Development Applications of whole rock geochemistry and heavy minerals to petroleum exploration in the Bowser and Sustut basins David Ritcey Geological Survey of Canada Earth Sciences Sector Northern Resources Development Ken Ratcliffe Chemostrat Inc.

Northern Resources Development Outline Sampling Rationale Methods of Analysis Available Datasets Interpretation and Applications

Northern Resources Development General Strategy and Sample Selection Project initiated by EnCana Corporation Outcrop samples from GSC field mapping all major map-units multiple lithologies Analytical work by EnCana contracted to Chemostrat Inc.

Northern Resources Development Analyses and Datasets 153 samples analyzed by alkali-fusion and ICP-OES & ICP-MS 7 major element oxides and 37 trace elements Heavy mineral separations and grain counts on a subset of 30 sandstones and conglomerates Data on CD …and free

Northern Resources Development Initial presentation and analysis of data Stratigraphic assignment of all samples 3 lithological groups considered –Conglomerates –Sandstones –Siltstones-claystones Age assignment of samples

Northern Resources Development Chemostratigraphic approach Geochemical characterization of units –“fingerprinting” Correlation Indicators of provenance Geochemical modeling of rock compositions Implications for reservoir quality

Northern Resources Development Chemostratigraphic approach Characterize / Distinguish Map Units Selection of elements: –Empirical –Known relation to provenance, e.g. Cr, Ni from ultramafics, Ce in allanite –Relation to mineralogical composition, e.g. K 2 O and Cs in feldspars and clay minerals

Northern Resources Development Geochemical Profile

Northern Resources Development Geochemical Characterization Characterization allows classification and correlation Contrast Bowser Lake and Sustut groups.

Northern Resources Development Bowser Lake vs Sustut

Northern Resources Development Variations within Bowser Lake Group

Northern Resources Development Variations within Bowser Lake Group

Northern Resources Development Provenance Indications From Heavy Minerals and from Geochemistry Heavy mineral data may be presented in many ways –Profiles –Ratios, indices

Northern Resources Development Provenance Summary 4 main provenance types Eaglenest, Skelhorne, Muskaboo Creek, and Todagin are predominantly mafic (-ultramafic) Jenkins Creek is acid igneous dominated Groundhog-Gunanoot and Ritchie- Alger have mixed provenance Sustut Group has metasedimentary provenance (plus acid igneous)

Northern Resources Development Provenance Implications Sedimentary linkages between units

Northern Resources Development Geochemical Modeling Facies variation

Northern Resources Development Geochemical Modeling Feldspar abundance

Northern Resources Development Implications for Reservoir Quality Si/Al applied as a proxy for grain size and clay content

Northern Resources Development Conclusions It works! Templates can be prepared for stratigraphic classification by geochemistry Correlation is practical, effective Various forms of modeling are feasible Rapid “first pass” assessment is reasonable, to prioritize large areas