Abstract:

The skarn polymetallic deposit, an important deposit type in southeastern Inner Mongolia, is mainly distributed in southwest section of Huanggang-Wulanhot polymetallic metallogenic belt. Baiyinnuo Pb-Zn deposit, Haobugao Pb-Zn-Cu-Sn deposit and Huanggang Fe-Sn deposit are representative skarn deposits in the area, and they are also important producing area for lead, zinc and tin in Northern China. The authors summarized and analyzed the effectiveness of geophysical and geochemical exploration method, and established comprehensive geological, geophysical and geochemical ore-prospecting models for skarn polymetallic deposit in the region. The ore bodies in these skarn deposits often are located in interlayer of Permian crystalline limestone or marble. The collapse part of compound anticline axis is favorable position for ore-forming materials precipitating by the tectonic movement. The mineralization, especially lead-zinc, has close relationship with manganese and calcium pyroxene skarn. The Cu, Pb, Zn, Ag, Sn contents in the strata and acid intrusive rocks near the ore district are much higher than the background value. In addition, the alteration zone associated with the mineralization and ore bodies exposed appear the geochemical anomalies with high-intensity, high-contrast and good-clear zoning. The element zoning shows that the geochemical halo in the front ore body are characterized by As, Sb, Hg, Pb and F, while the halo in the tail ore body by Sn, W and Mo. The ore bodies and mineralized skarn often display high polarization, high magnetic, high gravity and low resistivity (three high and one low) combination of anomalies.

Key words: skarn deposit, lead-zinc ore deposit, geophysical and geochemical anomaly, ore-prospecting model, Inner Mongolia