Rason Throssel combined ppm thorium grid geodetic

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 0.00042 degrees (approximately 44m) and shows thorium element concentration of the Rason-Throssel merge, 1991-1998 in units of parts per million (or ppm). The data used to produce this grid was acquired in 1991 by the WA Government, and consisted of 107758 line-kilometres of data at a line spacing between 200m and 400m, and 60m terrain clearance.

放射性伽马能谱测量法（radiometric/gamma-ray spectrometric method）通过探测地表附近的天然伽马射线变化，以反映钾（K）、铀（U）及钍（Th）的天然放射性衰变过程。所采集的数据将通过标准化处理流程进行质控，确保记录的响应仅来自地下岩石的放射性贡献。经处理得到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，以确保GA发布的最终数据满足使用需求。本次发布的放射性钍数据格网栅格单元尺寸为0.00042度（约44米），展示了1991-1998年Rason-Throssel合并区域的钍元素浓度，单位为百万分比（parts per million，简称ppm）。本格网的原始数据由西澳大利亚州政府（WA Government）于1991年采集，总测线长度达107758线公里，测线间距介于200米至400米之间，地形离地高度为60米。