3 125/336/58/ North-east orientated faults or lineaments represent extensional/normal displacements (where displacement is inferred) and generally dip to the north-northwest. This inference is made based on general knowledge of the structural relationships of the region, as well as various anecdotal level conversations with the OGL and supporting consultants. o Dip has been set at 60˚ South-east, east-west and north-north-west (i.e. south-south-east) orientated lineaments have been inferred to dip vertically/ near vertically. This is under the presumption that the local stress field within the region would see these orientations typically comprising more strike-slip displacement as opposed to extensional displacement. Faults or lineaments with surface exposures that project further than several hundred meters across the ground have been inferred to extend to significant depths and therefore have been extrapolated to the boundaries of the long-section. Where this is not the case, the lineaments have been extended a nominal 200 – 250 m depth below ground. Lithologies shown on the CSM are taken directly from the 1:50,000 GNS Waihi area map with the following simplifications made: o Tauranga Group and Whitianga Group Deposits that outcrop at the southern end of the map series have been grouped into a single unit o Ryolite and tuff eruptive sequences outcropping at the northern end of the map series have been grouped into a single unit, “Coroglen Subgroup” Standard relative stratigraphical relationships have been observed for the lithology shown, based on the ageing data for the various units presented by the 1:50,000 GNS Waihi area map Geochemical surface mapping data supplied by OGl has been simplified to show only the significant argillic alteration zones, and zones were strong quartz replacement (silicification) has been recorded. o The relatively large halos of smectite alteration have been assumed to represent predominantly surficial weathering processes however this is unconfirmed. As such, the projection of this zone within the long-section remains shallow. o Illite-smectite and silification mapped zones have been inferred to be more directly controlled by subsurface hydrothermal upwelling’s (based on typical hydrothermal epithermal mineral assemblages known for the Waihi region), and as such to be faultcontrolled. Accordingly, they have been projected below ground to be orientated to the dominant structural fabric (NE orientated, NW dipping). o Some extrapolation and inclusion of geochemical alteration zones has been made by GHD based on interpretation of surface features identifiable from review of historical aerial photographs). The lithological contact and distinction between Waipupu Formation Andesite and Whiritoa Andesite has been extended from the interpretation of thse units per the mapped 1:50,000 GNS Waihi geology. In reality, we expect these two units to be largely monolithic. 1.6 Output The CSM is given is presented in the following outputs: Surface 1:8000 scale Geological Map Series 1:2500 scale 2D tunnel long-section (project looking west) GHD is able to provide, on request and at the permission of OGL, the following supporting data: Shape files and map files associated with all geological features shown on the above outputs
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