Tallaringa North - Th equivalent concentration grid (AWAGS, no nasvd)

The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. The Geological Survey of South Australia commissioned the Gawler Craton Airborne Survey (GCAS) as part of the PACE Copper initiative. The airborne geophysical survey was flown over parts of the Gawler Craton in South Australia. The program was designed to capture new baseline geoscientific data to provide further information on the geological context and setting of the area for mineral systems (http://energymining.sa.gov.au/minerals/geoscience/pace_copper/gawler_craton_airborne_survey). This radiometric thorium grid has a cell size of 0.00042 degrees (approximately 44m) and shows thorium element concentration of the Tallaringa North Airborne Magnetic Radiometric and DEM Survey, SA, 2017 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2017 by the SA Government, and consisted of 98230 line-kilometres of data at 200m line spacing and 60m terrain clearance. To constrain long wavelengths in the grid, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey grid.

放射性测量法（radiometric method），亦称伽马射线能谱法（gamma-ray spectrometric method），可检测地球表面附近探测到的伽马射线自然波动，此类波动源于钾（K）、铀（U）及钍（Th）的天然放射性衰变。所采集的数据将通过标准流程进行处理，以确保记录的响应仅源自地下岩石。经处理后得到的数据集可通过解译揭示地表以下的地质构造。经处理的数据将由南澳地质调查局（Geological Survey of South Australia，简称GA）的地球物理学家进行质量检查，以确保GA发布的最终数据符合使用要求。南澳地质调查局牵头开展了高勒克拉通航空测量（Gawler Craton Airborne Survey，简称GCAS）项目，作为PACE Copper initiative的组成部分。此次航空地球物理测量作业覆盖了南澳境内高勒克拉通的部分区域。本项目旨在获取全新的基础地球科学数据，以进一步阐明该区域的地质背景与成矿环境，为矿产系统研究提供支撑（数据来源链接：http://energymining.sa.gov.au/minerals/geoscience/pace_copper/gawler_craton_airborne_survey）。本放射性钍元素网格的单元格大小为0.00042度（约合44米），展示了2017年南澳塔拉林加北航空磁测、放射性测量与数字高程模型（Digital Elevation Model，简称DEM）调查中钍元素的浓度分布，单位为百万分比（parts per million，简称ppm）。用于生成本网格的数据由南澳政府于2017年采集，总测线长度达98230千米，测线间距为200米，飞行离地高度为60米。为约束网格中的长波长信号，项目采用了独立数据集——全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey，简称AWAGS）的航空磁测数据，以管控本次测量网格的基准电平。