Drilling has identified that this CSAMT geophysical anomaly appears to be related to advanced argillic alteration
('lithocap') under cover.
The prospect is defined by a large 1.5-by-1-kilometer zone of argillic alteration
, with the alteration zone possibly related to an epithermal gold system.
The alteration zones of a typical porphyry system are also present including propylitic and potash, while, some phyllic and argillic alteration
has also been observed.
Wildhorse Plain hosts an area of probable epithermal alteration made up of fluorite, argillic alteration
and minor sulphide.
Nor is there a zonation of oxygen isotopic compositions that would be predicted for intrusion-driven water-rock interaction--magmatic fluids near the intrusive centres followed progressively outwards by [[sup.18]O-depletion (propylitic alteration) and then [[sup.18]O-enrichment (argillic alteration
), as meteoric-hydrothermal waters became dominant in the cooling system through circulatory fluid flow above the brittle-ductile boundary as is evident in the distribution of [[delta].sup.18][O.sub.WR] values in Figure 4.
Multiple veins have been identified, with argillic alteration
and erratic silver and gold values.
According to Dia Bras, "high grades of gold in outcrop over two structural trends, as well as highly anomalous stream sediment samples that indicate a gold mineralized area in the core of the large argillic alteration
area" exist on the La Verde Prospect.
The incidental discovery of sizeable potential argillic alteration
in the Kunlun is a 'bonus' discovery and may be related to the gold in the Hotien district.