Australian National Magnetic Data Collection

This data collection are comprised of magnetic surveys acquired across Australia by Commonwealth, State and Northern Territory governments and the private sector with project management and quality control undertaken by Geoscience Australia. Magnetic surveying is a geophysical method for measuring the intensity (or strength) of the Earth's magnetic field, which includes the fields associated with the Earth's core and the magnetism of rocks in the Earth's crust. Measuring the magnetism of rocks, in particular, provides a means for the direct detection of several different types of mineral deposits and for geological mapping. The magnetism of rocks depends on the volume, orientation and distribution of their constituent magnetic minerals (namely magnetite, monoclinic pyrrhotite, maghaemite and ilmenite). The instrument used in magnetic surveys is a magnetometer, which can measure the intensity of the magnetic field in nanoteslas (nT). Magnetic surveys in this collection have been acquired using aircraft or ship-mounted magnetometers and are a non-invasive method for investigating subsurface geology.

本数据集收录了澳大利亚联邦、各州及北领地政府与私营部门在澳大利亚全境开展的磁法测量数据，相关项目的管理与质量控制工作由澳大利亚地质调查局（Geoscience Australia）承担。磁法测量是一种地球物理勘探手段，用于测定地球磁场的强度，该磁场既包含地球核部产生的磁场，也涵盖地壳岩石所携带的磁性。尤为重要的是，对岩石磁性的测定可实现多种不同类型矿床的直接探测，同时也可为地质填图工作提供技术支撑。岩石的磁性取决于其所含磁性矿物的含量、赋存方位与分布特征，此类磁性矿物主要包括磁铁矿（magnetite）、单斜磁黄铁矿（monoclinic pyrrhotite）、磁赤铁矿（maghaemite）与钛铁矿（ilmenite）。磁法测量所用的仪器为磁力仪，可测定以纳特斯拉（nanoteslas, nT）为单位的磁场强度。本数据集收录的磁法测量数据均采用航空或船载磁力仪采集，属于一种可用于探测地下地质状况的无损勘探方法。