Abu Donia Atef M
Studies department, Nuclear Materials Authority, P.O. Box (530) El-Maadi, Cairo, Egypt.
Radiat Prot Dosimetry. 2023 Mar 17;199(4):294-311. doi: 10.1093/rpd/ncac270.
A major number of mineral deposits are related to hydrothermal processes. Therefore, the mapping of the hydrothermally alteration areas, connected with mineralization, is crucial in the search for metal deposits. To achieve this purpose, areas of hydrothermal alterations are targeted by processing the airborne gamma-ray spectrometric data to detect areas enriched in potassium that may indicate the existence of potassic alteration zones, which are often associated with hydrothermal alterations accompanied by mineral deposits. Data processing and analysis were performed using the K/eTh ratio, deviation of ideal potassium (Kd) and F-parameter. Besides, determining the environmental radiation risk due to the fact that the study area contains many excavation sites for various mining materials and quarries. Hydrothermal alteration indicator maps show five known mineralizations of gold, copper, molybdenum, fluorite and wolframite, which are associated with hydrothermal processes that took place in the study area. It is possible to note the intimate correlation of mineral deposits present in areas with high potassium content. Positive correlation between the computed hydrothermal alteration indicators (K/eTh, Kd and F-parameter), shown on the ternary image map, revealed favorable high and intermediate targets for the detection of various mineral deposits in the study area. On the other hand, the estimated mean values of absorbed dose rate for all rock units were within the permissible range (28-120 nGy h-1), and the mean annual effective dose rate was below the permissible limit of 1.0 mSv y-1 for these rocks.
大量的矿床与热液作用有关。因此，绘制与矿化相关的热液蚀变区域图对于寻找金属矿床至关重要。为实现这一目的，通过处理航空伽马射线能谱数据来确定热液蚀变区域，以检测富含钾的区域，这些区域可能表明存在钾质蚀变带，而钾质蚀变带通常与伴有矿床的热液蚀变有关。使用钾/钍比值、理想钾偏差（Kd）和F参数进行数据处理与分析。此外，鉴于研究区域包含许多各类采矿材料的挖掘场地和采石场，还需确定环境辐射风险。热液蚀变指示图显示了金、铜、钼、萤石和黑钨矿的五个已知矿化点，它们与研究区域内发生的热液作用有关。可以注意到高钾含量区域内存在的矿床之间存在密切关联。三元图像图上显示的计算出的热液蚀变指示参数（钾/钍比值、Kd和F参数）之间的正相关关系，揭示了研究区域内检测各类矿床的有利的高、中级目标区域。另一方面，所有岩石单元的吸收剂量率估计平均值在允许范围内（28 - 120纳戈瑞每小时），并且这些岩石的年平均有效剂量率低于1.0毫希沃特每年的允许限值。
