the problem of the Daly gap: an example from Rarotonga Received: 27 September 2000 / Accepted: 7 June...alkalic rocks are a minor component of many ocean island volcanic suites, and include trachyte and phonolite...magmas. The phonolites and foidal phonolites on Rarotonga were formed by low pressure crystal fractionation...Fractionation continued with the crystallization of aegirine-augite + nepheline + kaersutite + magnetite + apatite...fractionation of anorthoclase + nepheline + aegerine-augite + Fe±Ti oxides. As the magmas fractionated in both