The Geological Survey of India (GSI), established in 1851, is a government organisation in India which is an office attached to the Ministry of Mines of Union Government of India for conducting geological surveys and studies. It is one of the oldest of such organisations in the world and the second oldest survey in the country. The GSI is the prime provider of basic earth science information to the government, industry and the general public, as well as responsive participant in international geoscientific fora, the vibrant steel, coal, metals, cement and power industries.
The roots of the Geological Survey of India may be traced to 1836 when the Coal Committee, followed by more such committees, was formed by the British East India Company to study and explore availability of coals in the eastern parts of India. David Hiram Williams, one of the first surveyors for the British Geological Survey, was appointed 'Surveyor of coal districts and superintendent of coal works, Bengal' on 3 December 1845 and arrived in India the following February. The phrase "Geological Survey of India" was first used on Williams's Map of the Damoodah and Adji Great Coal Field (Dec 1847). On 4 February 1848, Williams was appointed the "Geological Surveyor of the Geological Survey of India", but he fell off his elephant and, soon after, died with his assistant, an F. B. Jones, of 'jungle fever' on 15 November 1848, after which John McClelland took over as the "Officiating Surveyor" until his retirement on 5 March 1851.
The work of the Geological Survey remained primarily exploration for coal, mainly for powering steam transport, and later oil reserves, and ore deposits. In 1852, Sir Thomas Oldham, father of Richard Dixon Oldham, broadened the ambit of the scope of functioning of the Geological Survey of India by advancing the argument with the government that it was not possible to find coal without first mapping the geological structure of India. Thus, the Geological Survey commenced to map the rock structures and strata and their age and relationships in India. Because the method of Radiometric dating wasn't developed at that time, the age of rock strata had to be estimated from the presence of index fossils, and consequently, much of the geologists' efforts were spent in finding these index fossils.
The Geological Survey of India made important contributions to seismology by its meticulous investigations and studies and detailed reports on numerous Indian earthquakes of the 19th and early 20th century. Richard Dixon Oldham, who worked for the Geological Survey like his father, first correctly identified p- and s-waves, and hypothesised and calculated the diameter of the Earth's core.