五大连池裂谷型富钾火山岩带的岩石学与地球化学

Petrology and Geochemistry of Rift Type Wudalianchi K-rich Volcanic Rock Zone

以五大连池火山群为中心的小古里河—科洛—五大连池—二克山近SN向的裂谷型富钾火山岩带,除了科洛火山群的火山活动从晚第三纪持续到第四纪,其它火山主要限于第四纪的喷发活动。按照岩石学和化学成分,晚第三纪和第四纪富钾火山岩分别命名为白榴碧玄岩和白榴玄武岩。富钾火山岩的岩石学、主微量元素和Sr-Nd-Pb同位素地球化学特征表明,富钾火山岩来自交代的EMI地幔。

In the Xiaogulihe—Keluo—Wudalianchi—Erkeshan rift-type K-rich volcanic rock zone, striking north —south and taking the Wudalianchi volcano group as the centre, volcanism was limited to the eruption in the Quatenary except the Keluo volcano group whose volcanism was active from Late Tertiary to Quatenary. On the base of petrology and chemical composition, the K-rich volcanic rock of the Late Tertiary is named leucite basanite and the K-rich volcanic rock of the Quatenary is named leucite basalt, respectively. The evidences of petrology, major element, trace element and Sr-Nd-Pb isotops suggest that the K-rich volcanic rocks were derived from the metasomatic EMI mantle.