宁芜北段姑山组火山岩系的时代讨论

A Discussion on the Time of Volcanic Rock System for Gushan Fm., North Section of Ning-Wu

宁芜北段姑山组是介于大王山组和娘娘山组之间的火山岩系 ,实测钾氩法同位素年龄为 114 0Ma～ 91 0Ma ,孢粉组合与大王山组相比以裸子植物花粉较少、蕨类植物孢子较多为特征 ,因而 ,姑山组的时代主要为早白垩世晚期 ,部分可延续至晚白垩世早期。

Gushan Formation in the north section of Ning Wu belongs to volcanic rock system lying between Dawangshan Formation and Niangniangshan Formation with a measured isotopic age of 114 0Ma～91 0Ma determined by potassium argon method. Compared with Dawangshan Formation, the sporopollen is featured by less Gymnospermae pollen and more Pteridophyta. So, the author states that the time of Gushan Formation belongs predominantly to the late period of Early Cretaceous Epoch and locally to the early period of Late Cretaceous Epoch.