Oceana Gold New Zeland Limited Hydrogeology Support for WKP Underground Updated Conceptual Model 2.3. Once packer testing results were re-analyzed using the above process, results were compiled and compared to data on borehole geology, vein distribution, drilling water losses, and geotechnical information (RQD) to inform development of the conceptual hydrogeologic model. Data evaluation included detailed review of bore logs and core photos for many of the exploration bores. A variety of graphical and analytical techniques were used during this process to help inform and visualize the conceptual model, including: Review of borehole core data: photos, RQD and field description. Generation of stratigraphic profiles for each bore, for comparison of the packer testing results with lithology, alteration, weathering, RQD, and core photos. Generation of schematic cross sections in 2D for each drillhole with hydraulic testing data, including structures, lithology, and vein architecture. Subsequent population of cross sections with drill traces, packer testing results, water losses from drilling, and estimated water table elevations. Generation of a 3D schematic database in Leapfrog. Extrapolation / projection of nearby exploration bores into the 2D sections, for use in broader assessment of vein properties. Concatenation of various data sets for the projected exploration bores in each section. Application of exploratory data analyses (EDA) techniques to concatenated data sets, including production and review of variable histograms and correlation matrices. Results of the data evaluation process are discussed in Section 3. 2.4. Regional and local geology of the Wharekirauponga deposit have been extensively discussed in previous reports and studies. The following three paragraphs were taken from GWS report (WAI985-000-REP-LC-0030A) as a brief general overview of the geological setting: The geology is described as Whiritoa Andesite on the eastern side of the valley which is truncated by the Edmonds Fault that dips to the west. Whakamoehau Andesite is located on the western side of the valley and is described as being post-mineralization Andesite and dacite. The mineralized unit is described as the Edmonds Formation that is composed of rhyolitic flows and lapilli tuff that is commonly hydrothermally altered. The mineralized rhyolitic volcanics are fault bound and it is interpreted that they are uplifted to some degree. The main veins are considered to be related to north-east trending, moderately dipping (60-65°) extensional step faults that relate to graben development and are up to 10 m wide. Secondary veins are developed between, or adjacent to, the main veins that are oriented northerly to north easterly, are moderately to steeply dipping and are up to 1 m wide. The existent geological model is primarily based on the main lithological units and identified vein systems, with no specific consideration of the hydrogeology or potential hydrostratigraphic units. The scope of this task considered that, through data evaluation, it may be possible to identify permeability domains related to specific lithologic, structural, and geologic features that could potentially be added to the geologic model as a guide for development of the groundwater model.
RkJQdWJsaXNoZXIy MjE2NDg3