Igneous and Metamorphic Petrology
Igneous and Metamorphic Petrology
复制标题
DOI：
10.1180/minmag.1983.047.344.33
复制
发表时间：
1983-09
影响因子：
2.7
通讯作者：
D. A. Carswell;F. G. F. Gibb-F.-G.-F.-Gibb-2301811758
中科院分区：
文献类型：
--
作者：
D. A. Carswell;F. G. F. Gibb-F.-G.-F.-Gibb-2301811758
Introduction: You have learned about Bowen's reaction series and the importance of crystal-melt fractionation in generating the spectrum of observed igneous rock compositions (e.g., basalt, andesite, rhyolite). Magmatic differentiation is the process by which diverse rock types are generated from a single magma. Differentiation is accomplished by crystal-melt fractionation, a two-stage process that involves the formation and mechanical separation of compositionally distinct phases. In 1844 Charles Darwin described flows from the Galápagos Islands in which the lowest flows contained greater proportions of feldspar crystals. These observations led Darwin to propose that density differences between crystals and melt would result in mechanical separation of these two phases and the formation of different magma types. This process, known today as gravity settling, was the focus of detailed experimental studies by N.L. Bowen. Today, several additional mechanisms of crystal-melt fractionation are also recognized, including: flow segregation, filter pressing, and convective melt fractionation.
