Grove and Brown present a perspective on the evolution of thought on the origin of compositional diversity in igneous rocks. They explore the difficulty Bowen faced due to a paucity of data and samples, noting that basalts from mid-ocean ridges had yet to be dredged from the ocean floor. During Bowen’s tenure, major element analyses could only be made on bulk rocks, with no trace element or isotopic data. In contrast, today’s PetDB database contains over 1.7 million bulk rock analyses and more than 655,000 volcanic glass analyses.
Fig 1B. Experimentally determined liquid lines of descent plotted with glass analyses along the Galapagos Spreading Center.
Grove, M., Brown, S., 2018, Magmatic processes leading to compositional diversity in igneous rocks: Bowen (1928) revisited, American Journal of Science, vol. 318, pp.1-28, doi:10.2475/01.2018.02