摘要
The high-grade iron deposits of the Gongchangling type occur in the Archaeozoic Anshan Group of this region and are classified as stratabound deposits. They underwent stages of sedimentation, regional metamorphism, and hydrothermal enrichment during the course of formation. Hydrothermal enrichment is notable in the vertical zoning pattern, i.e., from the bottom upwards, zone A hlgh-grade magnetite ore; zone B low-grade magnetite ore; zone C transition zone between hematite and magnetite ore ; zone D low-grads hematite ore ; zone E alterated cover. Through the vertical profile of the orebody, regular variations can be recognized in iron concentration, in the characteristics of country rock alteration, the ore-controlling structure and the properties of the hydrothermal ore-forming fluids. A two-fold source, deep hot brines and shallow thermal groundwater, is suggested for the origin of the ore-formlng hydrothermal fluids. The two fluids, mixed in varying proportions, are responsible for the various geochemical reactions during the course of ascending, exerting controls on the iron content of ore and the pattern of vertical zonation. A better understanding of the vertical zonation is expected to shed light on the exploration for such type of ore deposits.
The high-grade iron deposits of the Gongchangling type occur in the Archaeozoie Anshan Group of this region and are classified as stratabound deposits. They underwent stages of sedimentation, regional metamorphism, and hydrothermal enrichment during the course of formation. Hydrothermal enrichment is notable in the vertical zoning pattern, i.e., from the bottom upwards, zone A high-grade magnetite ore; zone B low-grade magnetite ore; zone C transition zone between hematite and magnetite ore; zone D low-grade hematite ore; zone E alterated cover. Through the vertical profile of the orebody, regular variations can be recognized in iron concentration, in the characteristics of country rock alteration, the ore-controlling structure and the properties of the hydrothermal ore-forming fluids.A two-fold source, deep hot brines and shallow thermal groundwater, is suggested for the origin of the ore-forming hydrothermal fluids. The two fluids, mixed in varying proportions, are responsible for the various geochemical reactions during the course of ascending, exerting controls on the iron content of ore and the pattern of vertical zona-tion. A better understanding of the vertical zonation is expected to shed light on the exploration for such type of ore deposits.
出处
《地球化学》
CAS
1982年第3期260-269,共10页
Geochimica
