The volcanic rock from the Niangniangshan Formation in the Ningwu (Nanjing—Wuhu) volcanic basin is used for Rb-Sr isotopic dating. The Rb and Sr isotopic ratios of whole rock, Kfeldspar, plagioclase and biotite form a good linearity in n(87Rb)/n(86Sr) vs. n(87Sr)/n(86Sr) space. The isochron age of innerminerals is 1331±32 Ma (MSWD=0096), which represents the formation age of the volcanic rocks from the Niangniangshan formation. This age is consistent in error with that of underlying volcanic rocks of the Longwangshan and the Dawangshan formations. Chronological comparisons indicate that the volcanic rocks from the Luzong (Lujiang—Zongyang) and Ningwu volcanic basins were formed during a shortterm around 130 Ma, implying that the extension of the Lower Yangtze region might achieve its maximum at ca 130 Ma.
闫峻,俞永飞,陈江峰.2009.宁芜地区娘娘山组火山岩Rb-Sr同位素定年及其意义[J].地质论评,55(1):121-125,[DOI]. .2009. Rb-Sr Isotopic Dating of Volcanic Rocks from the Niangniangshan Formation in the Nanjing—Wuhu area and Its Geological Implications[J]. Geological Review,55(1):121-125.