Introduction

The Caijiaying Pb-Zn-Ag ore deposit locates at the northwest of Hebei Province, inner margin of northern to North China Craton (Figure 1), it is a super-large zinc deposit in the world and the Ag resource can reach to large type. There are many scientists researched the ore genesis from many aspects, the main genesis as follows: moderate-temperature hydrothermal vein filled metasomatism deposit (Huang D H etc.1991), ancient emanation exhalation-hot water sedimentary metamorphism-hydrothermal superimposition (Yang M Z, 2000), fluid evolution consistently (Wang L J, 2003). The metallogenesis of Caijiaying Pb-Zn-Ag ore deposit is the product of the identity structural-thermal event between the turn of stronger structural system and magma fluid metallization initiated by extensional process during in Mesozoic era in the eastern of North China Craton. But, the characteristics of alteration rock in the deposit have not been studied in detail.

Figure 1. Geological sketch map of the graphite ore-field in Sujiquan

Geological sketch map of the graphite ore-field in Sujiquan

1.arfvedsonite granite; 2. biotitic granite; 3.tuff, sandstone, siltstone containing jasperite; 4. fine sandstone and feldspathic sandstone; 5. sandy conglomerate containing fine sandstone; 6. siltstone feldspathic sandstone, tuff, sandy slate containing carboniferous shale. 7. tuff conglomerate, rhyolitic porphyry, tuff sandstone, conglomerate; 8. ultra-basic rocks; 9. graphite ore deposit; 10. Quaternary.