Assessment of indium prospecting potential in national-scale geochemical perspective, Papua New Guinea

The spatial distribution and statistics of indium in stream sediments from Papua New Guinea (PNG) were studied based on the results of Papua New Guinea National-Scale Geochemical Baseline (PNG-NGB) project (2015-2018). 1399 samples were collected covering approximately 128,000 km2 with sample density of approximately 1.1 site/100 km2. Indium concentration in the stream sediments of PNG ranged from 0.003 mu g/g to 0.24 mu g/g with a baseline (median) value of 0.067 mu g/g, a value of slightly higher than the upper crustal abundance of indium and Europe, North America, Australia and China. 64 indium anomalies are decided by cumulative - frequency method and contrast value, 39 anomalies are associated with porphyry, VMS, skarn, bauxite, and epithermal deposits and occurrences while porphyry and VMS mineralization is the most important type for indium prospecting and exploration. Parent rock type is also an important factor that controls the geochemical pattern of the indium distribution in stream sediments of PNG.