论文部分内容阅读
用化学分析法测定了亚利桑那州某些铜矿床和铜-铅-锌矿床附近的热液蚀变岩石中的铀、钍和钾含量。在蚀变较强的地带,钾含量比未蚀变区高出一倍。由于钍不作相当的增高,因此蚀变形成了钾/钍的高比值。在巴格达德斑岩型铜矿床上,观测得了铀含量的异常,局部地方呈久期不平衡。用汽车伽玛能谱仪测取每个测点的伽玛发射谱。对比能谱分析和化学分析的数据,能谱仪露头测量的标准误差为0.6%K、3.10~(-6)Th 和10.10~(-6)U。因此认为由热液蚀变引入的钾,具有足够被地表或空中能谱测量探测出来的数量;由于铀的不平衡,铀异常的能谱测量可能属于边缘状态。在这类普查工作中,钾/钍比值是一种有用的手段,它可用于区别热液蚀变的高钾含量带和未蚀变的高钾含量外来侵入体。
The contents of uranium, thorium and potassium in hydrothermally altered rocks near some copper deposits and copper-lead-zinc deposits in Arizona were determined by chemical analysis. In the more altered areas, the potassium content is twice as high as that in the un-altered area. As thorium does not make a considerable increase, so the formation of potassium / thorium high ratio of alteration. Abnormalities in uranium content have been observed on the Baghdad porphyry copper deposit, with uneven local durations. Gamma emission spectra of each measuring point were measured with a car gamma spectrometer. Compared with the data of EDS and chemical analysis, the standard errors of EDS for outcrop measurement are 0.6% K, 3.10 ~ (-6) Th and 10.10 ~ (-6) U. Therefore, it is considered that potassium introduced by hydrothermal alteration has sufficient quantity to be detected by surface or air energy spectrum measurement; due to the imbalance of uranium, the energy spectrum measurement of uranium anomaly may belong to the edge state. The potassium / thorium ratio is a useful tool in such census work and can be used to distinguish between high-K concentrations in hydrothermal alteration and non-alterable high-K intrinsics.