New Zealand (NZ) is home to a world class deposits of critical minerals, both in situ hard rock, detrital placer gravels, and coastal sands. These deposits are rich in minerals that are considered ‘critical minerals’ by the NZ government as they contain valuable minerals including rare earth elements (REE), titanium, scandium, zirconium, and tin. These minerals are important for the advancements in clean energy, medicine, chip manufacturing, satellites and other emerging technologies, which fuels their increasing demand.
The source of these mineral rich sands and gravels are intrusive igneous rocks outcropping within the mountain ranges west of the main divide. These tend to be in the ecologically sensitive high country and often within national parks. High levels of rainfall and erosion liberate these minerals from their host rock supplying them to rivers on their journey to the ocean. During this process, the critical heavy minerals become increasingly concentrated relative to their source rocks. Deposition of these minerals forms alluvial placer deposits within the valleys and, coastal marine placer deposits along the coastline. These deposits have long been mined for gold with historic reports of valuable critical minerals being rejected with tailings.
