Fine grained
soil fraction (−200 mesh, b0.074 mm) samples at a depth of
50–200 mm were taken on a traverse across the deposit (Zhang et al.,
2013). XRF and ICP-MS after a 4-acid treatment for total digestion and
selective sequential leach were used. Fig. 10 shows that the anomalous
distribution of the fine fraction soils after 4-acid and aqua regia extraction
and ammonium citrate plus hydroxylamine hydrochloride extraction
of the coatings of Fe–Mn oxides (FMM) coincide well with the
concealed deposit and the contrast of background and anomaly is
strong. From the southwest to the northeast, anomalies of analyzed
elements show horizontal zoning: (As–Sb–Hg–Ag–Au–U) → (Ag–Au–
Pb–Zn–Bi–Cu) → (Mo–Cu–Zn–U–W), which spatially correlates to the
corresponding mineral deposits.