 Her journal, The Structures, Origin, and Nomenclature of Acidic Volcanic Rocks of South Mountain, begins by identifying various rock structures formed by the volcano.Bascom argues that South Mountain's rock formations have changed over time, with some rocks originally showing signs of being rhyolite, but now holocrystalline rock.These rocks defy the nomenclature used to identify rocks invented by German and English scientists, so she created prefixes to add to these pre-existing names, to identify acidic changes in rocks.