摘要
本文利用钐钕同位素方法测试了四堡群文通组8件镁铁质-超镁铁质火山岩样品,获得成岩等时线年龄2 219±111(2δ)Ma的数据。证明了江南古陆南缘最古老地层单元四堡群为早元古代而不是中晚元古代的产物。
How old is Sibao Group, the oldest stratigraphic unit, in the southern margin of Yangtze massif? This problem has been focused on by Chinese geologists for long time. Eight samples of ultramafic-mafic volcanic rocks from Sibao Group in Northern Guangxi region are taken to be measured by Sm-Nd radioactive isotope method in this study. The isochron age 2219+111(2δ)Ma. of Sibao Group with high precision and accuracy got here shows that Sibao Group is Early Proterozio stratigraphic unit rather than Middle-Late Proteozoic one inffered by geologists in past. The result is quite useful for explaining the geological evolution of. the region.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第3期264-268,共5页
Geological Review
基金
国家青年科学基金(编号048007)
地质行业基金(编号88022)资助项目的阶段性成果之一
