富Nb玄武岩在冀北前寒武纪地区的发现

Discovery of the Precambrian Nb-Enriched Basalts in the Northern Hebei Province

在冀北太古代麻粒岩带与北侧的古元古代红旗营子群之间,沿古断裂带存在一系列古洋壳残片。最近发现其中广泛存在在其它地区罕见的富Nb玄武岩,Nb含量大于7×10-6,Nb/Th+Nb/La大于0.6,为古洋壳的厘定提供了新的佐证,为早前寒武纪地质构造演化研究提供了重要信息。

There are a series of ancient oceanic crust relics along the fracture belt between the Archean granulite belt and the Paleoproterozoic Hongqiyingzi group in the Nb-enriched basalt （Nb 〉 7 × 10^-6 and Nb/Th＋Nb/La North Hebei Province. Recently we have found widespread 〉 0.6 ） in this area, which is very rare in other regions, The discovery will provide powerful proof for distinguishing ancient oceanic crust and will also supply important information for the Precambrian geological and tectonic evolution.