Born in Fulham, O'Brien was educated at Tiffin Boys School, Kingston-upon-Thames and then went to Cambridge University where he read Natural Sciences, graduating in 1935. In 1936, he joined the Anglo-Iranian Oil Company, now British Petroleum and known universally as BP. His geological activities started in Southern Iran under senior geologist, Victor Boileau in the winter of 1936–37 where he assisted with Boileau's discovery of the Chogha Zanbil Ziggurat. O'Brien stayed for three years, and then was due for home leave. He happened to be in England when the Second World War started, and so joined up in the Royal Engineers, eventually becoming Major after service in Italy and Tunisia. He returned to work in Iran after the war and was also involved in exploration geology in Canada & other countries. His later geological work included a survey of the Rocky mountainsBoule and Bosche ranges. On 16 October 1958 he married Barbara Joy Kelly.
Archaeological theories
After his retirement in 1970, O'Brien began researching and writing about ancient civilisations, taught himself how to read cuneiform, and published three books on the subject. O'Brien published several other papers and books. "The Wandlebury-Hatfield Heath Astronomical Complex" described his surveying and discovering what he calls the Wandlebury Enigma or Line A Loxodrome, a claim which has not gained much acceptance. "The Megalithic Odyssey" presents evidence for an astronomical complex on Bodmin Moor in Cornwall, England, dated no later than c. 2500 BC. In the book he presents his view that 13 stone circles and 86 ridge-top cairns were designed and built for complex observational astronomy by a group of itinerant sages with links to Sumer. A review in the journal Archaeostronomy describes the book as "a mishmash of erroneous statements and poorly conceived and unsubstantiated arguments." The reviewer suggests that O'Brien has misapplied statistical methods and that coupled with a dubious interpretation of the archaeology "negates any value" it would have had as a claim for prehistoric archaeoastronomy. He further argues that the suggestion that the Sumerians introduced a calendar which made agriculture viable ignored the fact that agriculture had already existed in the area for over a thousand years, saying that "the book is full of statements which only confirm O'Brien's ignorance of our current knowledge of prehistory." O'Brien made the geological discovery of a substantial hanging river bed on São Miguel Island. Using Portuguese Admiralty Charts of the ocean floor in the area of the Azores in February 1973, he argued for the former existence of a large island at this location on the Mid-Atlantic Ridge which he believed to be Atlantis. He also made his own translations of the Bruce Codex, Askew Codex from Greek cursive characters in the now extinct, Upper EgyptianCoptic dialect. He also translated a series of tablets from Nippur including the Barton Cylinder, which he collectively grouped and called the Kharsag Epics. He claimed to have used these as a primary source to discover the location of "Kharsag", allegedly a location also mentioned in other Sumerian texts such as Atrahasis I that he equated with The Garden of Eden in The Second Book of Enoch and The Bible.
Positions, awards and accolades
O'Brien was awarded a CBE in 1971 for services to British interests in Iran.
Chairman of the Boards, managing director, Anglo-Iranian Oil Company, 1967–1971
Books
O'Brien, C.A.E., 1953, Salztektonik in Sudpersien, Stuttgart.
O'Brien, C.A.E., 1957, Salt Diapirism in South Persia, London and Amsterdam.
O'Brien, C.A.E., 1960, The Structural Geology of the Boule and Bosche Ranges in the Canadian Rocky Mountains, London.
O'Brien, C.A.E., 1975, , Thaxted.
O'Brien, C.A.E., 1983, The Megalithic Odyssey, A.C. Wellingborough.
O'Brien, C.A.E. & O'Brien B.J., 1985, The Genius of The Few, Wellingborough.
O'Brien, C.A.E., 1985, The Path of Light, The Deram Beas, India.
