Pilbara Block (Port Hedland, Marble Bar, Nullagine), WA. 1985 (P508), radiometric line data, AWAGS levelled

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. This Pilbara Block (Port Hedland, Marble Bar, Nullagine), WA. 1985 (P508), radiometric line data, AWAGS levelled were acquired in 1985 by the WA Government, and consisted of 42713 line-kilometres of data at 1500m line spacing and 150m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.

放射性测量法（radiometric method），亦称伽马能谱测量法（gamma-ray spectrometric method），通过探测地表附近的伽马射线自然变化，量化钾（K）、铀（U）及钍（Th）的天然放射性衰变所产生的信号。所采集的数据将通过标准处理流程进行校准，确保记录的响应仅源于地下岩石。该方法生成的数据集可通过解译揭示地下地质构造。经处理的数据将由GA地球物理学家开展质量核查，确保GA发布的最终数据满足应用需求。本次数据集为1985年采集的西澳大利亚州（Western Australia, 简称WA）皮尔巴拉地块（覆盖黑德兰港、大理石巴、纳拉金区域）放射性测量测线数据（编号P508），经全澳航空地球物理调查（Australia-wide Airborne Geophysical Survey, 简称AWAGS）平差校正；该数据由西澳大利亚州政府采集，总测线长度达42713线公里，测线间距为1500米，离地高度为150米。为约束数据中的长波长分量，研究团队采用独立数据集——全澳航空地球物理调查的航空磁测数据，作为本次调查数据的基准电平控制依据。本次调查数据已基本完成全澳航空地球物理调查基准下的平差处理。