Martin AP, Smith Lyttle B, Allibone AH, Blakemore H, Cox SC, Craw D, Doyle S, Kellett RL, MacKenzie DJ, Mortimer N, Ritchie T, Sahoo TR, Stephens S. 2021. Geology of Hyde-Macraes Shear Zone and Waihemo Fault Zone area, northeastern Otago. Lower Hutt (NZ): GNS Science. 2 digital map sheets, scale 1:50,000. (GNS Science geological map; 9). doi:10.21420/R370-0P15.
Abstract
Geology of the Hyde-Macraes Shear Zone and Waihemo Fault Zone Area is a new 1:50 000 scale geological map of northeastern Otago. The >3000 km2 map area includes the trans-crustal Waihemo Fault Zone, the economically significant Hyde-Macraes Shear Zone in the Otago Schist and the western edge of the Canterbury Basin. The map area is two-thirds onshore and one-third offshore, amalgamated into a seamless geological map (sheet 1) with legend and cross-sections (sheet 2). The maps capture current knowledge about the area as well as aiding the search for comparable structures elsewhere in Otago. The map illustrates the complexity of a small chunk of our local ‘frozen’ Mesozoic accretionary wedge and will be a useful analogue for those researching the active Hikurangi subduction margin.
Major findings are as follows. The Waihemo Fault Zone can be traced offshore in the interpreted seismic data for at least 10 km. The Hyde-Macraes Shear Zone cannot be traced offshore and structural data suggests it may pinch out close to where the Austral Superprovince cover sequence overlies the Rakaia Terrane near the coast (east). Magnetically distinct greenschist units can be traced as continuous layers in the Otago Schist rocks for up to 10 km. Map features include the following: unpublished structural data and mapping; re-processed offshore data from seismic; nomenclature is Litho2014; geological interpretation of geophysical data onshore and offshore; up to date structural and historical resources data and; up to date mining data. (auth)
Digital geological data and web services are available through the Dataset Catalogue:
- NZL GNS GM9 HMSZ geology https://doi.org/10.21420/59NX-QR39
