Opposition parties are questioning why the Government is undertaking aerial surveys of world heritage land if it does not plan to mine it.
The Government intends to conduct aero-magnetic surveys of the South Island's West Coast, including a world heritage area.
Conservation Minister Kate Wilkinson says the survey to get data for which there are a range of uses and the information will be particularly valuable for soils data and land capability assessments.
Labour says the surveying will inevitably lead to excavation, but Ms Wilkinson told a Parliamentary select committee she sees no conservation issue in looking at the resources.
The Government says no mining will take place on Schedule Four land or World Heritage Sites.