Hughes received the first part of his education at Leamington and Llandovery, and matriculated at Trinity College, Cambridge in 1853, from which he graduated in 1857, and as M.A.
He also believed the 'Old Red Conglomerate to form a sort of passage between the Mountain Limestone and the Millstone Grit'.
Hughes returned to Cambridge University to succeed Adam Sedgwick as Woodwardian Professor of Geology in 1873.
Nine candidates had applied for this post; Hughes got it with a small majority over Professor Thomas George Bonney.
She also acted as a chaperone so that women students could attend fieldwork, in addition to lectures and practical classes.
Whilst Woodwardian Professor, McKenny Hughes endeavoured to establish a lasting memorial to Adam Sedgwick, in the form of a Museum and school of geology.
His grandson, Graham Hughes, was later the art director of Goldsmiths' Company, who were behind the renaissance in modern silver design.
His over 50 research publications, mainly on work performed during his time at the Survey, are mainly about Precambrian and Palaeozoic formations in Wales, as well as of the Lake District.
17 boxes of the records of Thomas McKenny Hughes are at the Sedgwick Museum of Earth Sciences.
The collection contains correspondence with contemporaries including Sir Charles Lyell and his wife; reports and papers concerning both his diplomatic and geological work 1860-1880s; records of the international geological congresses in Bologna, London, Zurich and Russia 1880s–1890s; tour and field-note books including sketches and annotated drawings; maps; records relating to the Woodwardian Museum; drafts of papers and speeches; and some photographic albums.
[6] These derive from Hughes membership of the Council of the Cambs & Isle of Ely Chamber of Agriculture, of which he was vice-chairman in 1902 and chairman in 1903–4.