Maurice Chaper was a French civil engineer and member of the Societe Geologique de France. He studied geology and palaeontology at the School of Mines in Paris, but did not obtain his final diploma. After working for some time in France he carried out a number of geological surveys in Central America, where he worked on the Panama Canal project, in the Caribbean, Western North America, tropical South America, the Caucasus, South East Asia, west tropical Africa, and Sri Lanka. In addition to geological specimens he also made zoological and botanical collections. In 1870 he became a captain in the national guard and the next year was promoted to lieutenant-colonel.
In 1879 Chaper was commissioned to report on diamond mining in South Africa. He visited the districts of Paarl, Caledon, Swellendam, Robertson and Worcester before travelling up to Griqualand West. His remarks on the geology of the Southern Cape indicate that he was not well acquainted with the work of earlier geologists who had worked in this region, such as A.G. Bain*, A. Wyley*, and E.J. Dunn*. Nonetheless his remarks on the Dwyka tillite are of interest. Though it looked like an igneous rock, he observed planes of stratification in it and took samples back to France for petrographic analysis. At the Vaal River diggings he noted that the pebbles were mostly of igneous rocks like those at Pniel, and that garnets occur in the sandy matrix. At the diggins away from the river he found that the diamonds occur in what he called a consolidated serpentinous mud that had risen through openings in the overlying strata in successive flows at low temperature. From the pieces of gneiss and grits in the rock he inferred that the rocks deep down must be hornblendic gneisses, that these are overlain by sheets of various ophites (now named Ventersdorp lavas), and these again by shales. These observations and conclusions, as well as a description of the methods of diamond recovery, mining regulations, conditions on the fields, and plans of the mines, were published in a book, Note sur la Region Diamantifiere de l'Afrique Australe (Paris, 1880). It includes notes by the eminent French petrographers F. Fouque and A. Michel-Levy on the rocks collected. Chaper also published a paper on the diamond mines in South Africa immediately upon his return, in the Bulletin de la Societe Francaise de Mineralogie (1879). Years later he published a paper with the same title in the Comptes Rendus de l'Association Francaise pour l'avancement des Sciences (1892).
Chaper's later work includes a report on a scientific visit to Half Assini, on the coast of Ghana (1884), reports on a geological visit to the north coast of Venezuela (1886, 1888), notes on a diamondiferous pegmatite in India (1884, 1886), and notes on a voyage to Borneo (1894). His interest in zoology led, among others, to a paper on some new species of molluscs from South Africa and Half Assini (Bulletin de la Societe Zoologique de France, 1885).