Christie, A.B.; Barker, R.G.; Heron, D.W.; Lukovic, B.; Edbrooke, S.W. 2011 Towards an aggregate strategy : estimation of supply, demand and potential future resources in the Auckland region. Lower Hutt, N.Z.: GNS Science. GNS Science report 2011/33 30 p.
Abstract: Within the Auckland region, about 17 quarries are producing aggregate that is used mostly for road and building construction. Before the recession reduced demand, production within the region in 2007 was estimated at between 7 and 8 Mt, but demand exceeded local supply and required additional aggregate to be imported from the Waikato and Northland regions. These imports incur significant transport costs and associated effects. Per capita GDP appears to be the most reliable indicator of the demand for aggregate over the long term. Infrastructure projects, particularly roading, can create peaks in demand during their construction. Preliminary work to identify potential resources of high quality aggregate within the Auckland region has included assembly of a GIS and topographic analysis of areas of greywacke to identify a minimum target resource of 65 million m3. Several such sites were identified within the Hunua Ranges, and although most are located within the Hunua Regional Park and water supply area, some are located to the north, outside the protected areas. Other rock types that have potential are basalt and some conglomerate and volcanic breccia units. (auth)