Cobar P5009 EXT 6 Thorium ground concentration grid

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 radiometric thorium grid has a cell size of 0.00039074 degrees (approximately 40m) and shows thorium element concentration of the Cobar Magnetic and Radiometric Survey, 2021 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2021 by the NSW Government, and consisted of 53617 line-kilometres of data at 200m line spacing and 60m terrain clearance.

放射性测量法（radiometric method，亦称伽马能谱法（gamma-ray spectrometric method））通过检测地球表面附近的伽马射线自然变化，表征钾（K）、铀（U）及钍（Th）的自然放射性衰变所产生的辐射信号。所采集的数据将通过标准流程进行预处理，以确保记录的响应仅源自地下岩石的辐射信号。经处理得到的数据集可通过解译，揭示地下地质构造特征。经处理后的数据由GA地球物理学家开展质量校验，以确保GA发布的最终数据符合使用需求。本次发布的放射性钍格网（radiometric thorium grid）单元格大小为0.00039074度（约合40米），展示了2021年科巴磁力与放射性测量调查（Cobar Magnetic and Radiometric Survey, 2021）的钍元素浓度数据，单位为百万分率（parts per million，即ppm）。本格网所用数据由新南威尔士州政府（NSW Government）于2021年采集，总测线累计长度达53617千米，测线间距为200米，航测离地高度为60米。