什么是 Magmatic series？

A magmatic series is a suite of igneous rocks of one magmatic cycle or province related by differentiation from similar parent magmas and sharing characteristic chemical and mineralogical features. Three are commonly distinguished. The tholeiitic series starts from basalts saturated or slightly oversaturated in silica, with hypersthene in the norm, and shows a marked enrichment in iron at the start of its differentiation. The calc-alkaline series runs from basalt through andesite to dacite and rhyolite, with little or no enrichment in iron, and with hydrous minerals (hornblende, biotite) in its evolved members. The alkaline series starts from nepheline-normative basalts and evolves through the S and U fields of the TAS diagram towards trachyte and phonolite.