The geologist Richard Dixon Oldham (1858–1936) published the second edition of Geology of India in 1892 for the Geological Survey of India. The work is a thoroughgoing revision of the first edition of the same manual compiled by H. M. Medlicott (1829–1905) and W. T. Blanford (1832–1905), published in 1879. It contains one of the earliest and most important geological surveys of India. Owing to an increase in available data since the first edition, descriptions of the rock formations of the country are arranged chronologically. This edition is particularly important for the data on, and discussion of, the age and origins of the Himalayas. It includes other chapters on metamorphic and crystalline rocks, fossils, vegetation, volcanic regions, geological history, and rock formation. It is a key work of nineteenth-century geology which remains relevant for geologists studying the subcontinent today.
