Robert Heron Rastall, British geologist, first studied agriculture and for some time taught at Tamworth Agricultural College, Staffordshire. In 1899 he entered Christ's College, Cambridge, to study natural science and geology and obtained the degrees Master of Arts (MA) and later Doctor of Science (ScD). He was a Fellow of Christ's College from 1906 to 1913 and again from 1926 to his retirement in 1942. From 1915 to 1919 (during World War I) he was associated with the British War Office. In 1919 he was appointed lecturer in economic geology. He was a Fellow of the Geological Society of London (FGS), was elected a member of its council in 1915, and was awarded its Lyell Medal in 1946. He served on the council of the Mineralogical Society from 1918 and in 1903 became a member of the British Association for the Advancement of Science. In 1906 he published a catalogue of minerals, etc. in Cambridge University's Sedgwick Museum. He travelled in Europe, South Africa, the Malay Peninsula and elsewhere on geological work.
In 1906 Rastall was in South Africa, where he spent some time in Kimberley. At the annual congress of the South African Association for the Advancement of Science, held in Kimberley that year, he contributed a paper on "The petrography of the rocks surrounding the diamond pipes of the Kimberley District", which was published in the association's Report for that year (pp. 269-288). In this paper he described how the mine shafts at Kimberley pass through up to 300 m of light greenish quartz porphyries and acid amygdaloids, between which and the underlying granite are some 100 m of nearly horizontal sediments, including conglomerates.
Rastall's next contribution to South African geology was a paper, "Geology of the Worcester, Roberson and Ashton District (Cape Colony)", in the Quarterly Journal of the Geological Society (1911, Vol. 47, pp. 701-732). In this paper he noted that inclusions of rocks from the Malmesbury Group, and probably also from the Table Mountain Group, are absent in the Enon Conglomerate Formation, indicating that these two groups were not exposed in the region when the Enon conglomerates were formed. Also in 1911 he was co-author with F.H. Hatch* of a paper on "Dedolomitisation in the marble of Port Shepstone (Natal)", in the same journal.
Rastall published numerous papers on a variety of topics, including igneous petrology and metamorphism, sedimentary petrology, tectonics and the geological structure of southern and eastern England, stratigraphy, and economic geology, as well as numerous textbooks such as Agricultural geology (1916), Tungsten ores (with W.H. Wilcoxon, 1920), The geology of the metalliferous deposits (1923), Physico-chemical geology (1927), and, as co-author with F.H. Hatch, The petrology of the sedimentary rocks (3rd ed., 1938). He became editor of the Geological Magazine in 1919, serving in this position for more than 30 years.
