Reinout Willem van Bemmelen was educated as a mining engineer but later on preferred being a geologist, with a bias towards volcanology. He was also known for his dedication to geoscience, his tenacity and resilience, as well as being an inspiring teacher.

His studies of the regional geology of Indonesia led to recognition of the importance of island areas in the development of the Earth's crust. Long before others even thought about compiling an article on this archipelagos, he published his biggest contribution, the Geology of Indonesia (1949). Still often cited, this book covers broad aspects of the regional geology of Indonesia, which is prolific in terms of hydrocarbon and other mineral resources. Indonesia is part of the volcanic "ring of fire" and one of the most complex geological settings in the world because it lies at the junction of three major tectonic plates (Pacific, Indian-Australian, and Eurasian). Van Bemmelen also researched continental drift and the winds of the equatorial stratosphere.