| 摘 要： | Uhramafic rock area in Northern Hebei is situated in the northern margin of the North China Platform, along Chongli-Longhua deep major fracture zone which is the boundary of Inner Mongolia Anteclise and Yanshan subsidence Zone.In this region,Archeozoic eonothem darkcolor metamorphic rock(mainly plagio-hornblende gneiss) and ultramafic rock outcrops developed widely; Fractures are very developed;magmatism is very intensive and frequent.Along the deep fracture zone, various types of magmatism of an immense tectonic-magrnetic zone have provided favorable conditions for the mineralization of gold. In 1984,a gold ore deposit was discovered in Xiaozhangjiakou ultramafic massif,Chicheng county and another gold deposit had been discovered in Bulaotun ultramafic massif,Miyun county,in 1990.More and more people realized that ultramafic rocks have an important significance for the gold mineralization and began to pay more attention to the scientific research of ultramafic rocks in Northern Hebei province.
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