ISEA reversed event in the Cretaceous Normal Superchron(CNS):40Ar/39Ar dating and paleomagnetic results
会议名称：《中国科学院地质与地球物理研究所2004学术年会》
会议日期：2004年
学科分类：070902[理学-地球化学] 070801[理学-固体地球物理学] 0709[理学-地质学] 07[理学] 0708[理学-地球物理学]
基 金：supported by the National Natural Science Foundation of China(Grant No. 40221402) the Chinese Acadcmy of Sciences(Grant No.KZCX1- 07)
关 键 词：ISEA 40Ar/39Ar dating rock magnetism paleomagnetism west Liaoning.
摘 要：In order to provide the age for the ISEA(one reversed event in the CNS) a combined rock magnetic,paleomagnetic and geochronologic study has been conducted on two Cretaceous andesitic basalt lava flows from Sanbaoying, Liaoning Province of northeastern *** magnetic investigations show that pseudo-single domain(PSD) titanomagnetite with poor-Ti content is the dominant magnetic mineral in Sanbaoying lava *** systematic thermal demagnetization allowed us to isolate two remanence components after removing a low temperature component at 100℃/150℃;an intermediate temperature component with normal polarity at 150℃/200℃-380℃/400℃and the characteristic remanence component(ChRM) with reversed polarity above 400℃/450℃.Ar/Ar dating results show that Sanbaoying rocks were erupted at 116.0±0.3 *** of paleomagnetic results and Ar/Ar dating indicates that the reversed event recorded in Sanbaoying lavas corresponds to the ISEA event in the *** age determination for[SEA reversed event provides chronological evidence to study the relevance between global geological events that occurred in the CNS and geodynamo processes.