EVOLUTION OF THE PALEOZOIC NEPHELINITE SE RIES OF THE KOLA PROVINCE -EVIDENCE FROM P-DISTRIBUTION AND SR-DISTRIBUTION

We studied the distribution of P and Sr in plutonic, dike, and extrusi ve rocks of the Paleozoic nephelinite series of the Kola alkaline prov ince. For the plutonic series, the highest P abundances are observed i n melanocratic lithologies with melteigite compositions, and for the d ike nephelinite series, in nephelinites. Strontium shows two types of distribution depending on whether or not melilite lithologies form par t of the rock series. Type 1, characterized by Sr accumulation in meli litolites, comprises rock sequences of the Kovdor, Cape Turii, and Sal ma massifs. Type 2 is represented by the Khibiny Massif rock sequence, which is virtually devoid of melilite rocks. In the latter case, a po sitive Sr anomaly is observed in the melteigites, which, by and large, coincides with the P distribution pattern for the rock series. The be tween-type differences in P and Sr distribution in the derivatives of the initial nephelinite melts are shown to result from physicochemical parameters of magma crystallization, primarily, the volatile regime.