Sir Archibald Geikie corresponded with a number of people both socially and professionally. This sub-series includes the following correspondents:

John Phillips (1800-1874) wrote about maps of Naples and correspondence with Adam Sedgewick (1785-1873) and Sir Roderick Impey Murchison (1792-1871). This also includes a letter to to Sir Henry Thomas De la Beche (1796-1855) about various rock types.

John Arthur Phillips (1822-1887) wrote to thank Geike for sending him a paper on British geology and on the subject of sea cliffs.

Sir Edward Bagnall Poulton (1856-1943) wrote regarding an address he was working on and regarding an intended expedition.

James Powrie of Reswallie (1815-1895) wrote regarding some of his research at Carmyllie.

Sir Joseph Prestwich (1812-1896)

Raphael Pumpelly (1837-1923) offered to show Geikie the crystaline rocks of the Green Mountain and Lake Superior areas.

John Rae (1813-1893) wrote regarding his interest in the geology of the Orkneys.

Trenham Reeks (fl1869-1871) wrote in connection with business of the Geological Survey, including the health of Sir Roderick Impey Murchison (1792-1871) and the death of John William Salter (1820-1869).

Clement Reid (1853-1916) conveyed the findings of survey work in various localities in Norfolk and of some stratigraphical examinations he had made in the Edinburgh area. He also reported the loss of a lot of records, instruments etc. as a result of a house fire.

Sir Henry Enfield Roscoe (1833-1915) wrote about Count Paul Edmund De Strzelecki (1797-1879), who had discovered gold in Australia, who may have informed Sir Roderick Impey Murchison (1792-1871) of the fact.

Frederick William Rudler (1840-1914) mentioned work he had been doing with Professor Lehmann on crystalline chists.