Reginald Claude Sprigg was born 1 March 1919 on South Australia's Yorke Peninsula where his family were living in the small town of Stansbury. His parents were Claude Augustus Sprigg and Pearl Alice Irene née Germein, who had married on 17 September 1913 in Stansbury. Reg was their third and youngest child, a brother to D'Arcy Kingsley and Constance Vera (Connie).
His father's family were pastoralists, whilst the Germein family were mariners. The Sprigg family had relocated to the Yorke Peninsula after being "forced off their pastoral lease at Oulnina because of drought". The Germein family were ship chandlers in Mutton Cove, Devonport, Plymouth, England: three brothers came to Australia. One, Ben Germein is remembered as a hero of the Admella rescue mission.
Before he was five years old, the family had relocated to the Adelaide suburb of Goodwood, which gave the young Reg access to the beach where he collected shells and fossils. This boyhood hobby developed into a serious interest in geology, which brought him into contact with the geoscientists at the University of Adelaide to whom he took collected samples for identification.
In addition to pursuing his studies in geology, Reg developed drawing skills which gained him credit in the South Australian School of Arts and Crafts merit lists for 1934 and 1935.
He matriculated from the Adelaide Technical High School during 1938.
At the University of Adelaide, he was a pupil of Sir Douglas Mawson who said that "Sprigg was his best-ever student". He completed the requirements for his Bachelor of Science and then graduated Master of Science during 1942.
During 1940 he enlisted in the Australian Royal Engineers, and worked with Munitions from 1941 to 1942. He transferred to work with the soils division of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) until 1943.
Sprigg next worked for the South Australian Geological Survey, which sent him to reopen the Radium Hill Uranium Field during 1944, and to map the Mount Painter uranium field. At the time, uranium was believed to be rare, and was required for the Manhattan Project.
Sprigg was sent by the South Australian government during 1946 to inspect abandoned mines in the Ediacaran Hills, to ascertain whether old mines could be reworked profitably using new technologies. When he discovered the fossils, apparently while eating his lunch, he realised that they were very ancient, either of Early Cambrian, or possibly even of Precambrian age. He submitted a paper to the journal Nature, but it was refused. He travelled to London and presented his findings to the 1948 International Geological Congress, but failed to excite either interest or belief. Subsequent work by Prof Martin Glaessner at the University of Adelaide demonstrated that they were indeed of latest Precambrian age. Although Precambrian animal fossils had been reported before, they had not been accepted universally as organic. This discovery resulted ultimately in the definition during 2004 of the Ediacaran Period, the first new geological period created in more than one hundred years.
Of other significance, Sprigg helped establish Santos (an acronym for South Australia Northern Territory Oil Search), which discovered gas deposits in Cooper Basin, including the Moomba Gas Field, which supplies natural gas to South Australia, New South Wales and Canberra. During 1954 Sprigg formed the company Geosurveys of Australia, which was a consulting and contracting company for geological and geophysical work. They prospected for uranium in the Northern Territory and nickel in the north west corner area of South Australia as well as working for Santos.
During 1962 Geosurveys became incorporated into Beach Petroleum, of which Sprigg was General Manager.
During 1968, Sprigg purchased the pastoral lease of Arkaroola, a property and important uranium exploration field of 610 square kilometres in the Flinders Ranges of South Australia, and converted it into a wildlife refuge and tourist attraction. A governing board of Reg Sprigg, his wife Griselda and Dennis Walter, a mineralogist and old friend, oversaw the creation of Arkaroola Village out of existing buildings and the opening to tourists during October 1968.
Sprigg attracted the attention of the Australian Security Intelligence Organisation (ASIO) during 1950, due to Sprigg's knowledge of uranium deposits in Australia and throughout the world. During 1943 Sprigg had been secretary of the Australian Association of Scientific Workers. The association was concerned with the transfer of scientific workers from wartime to peacetime projects once hostilities ceased, and encouraged debate on the social responsibility of science. ASIO suspected the organization of communist ties, and as a result Sprigg was surveilled for some ten years.
During 1942, Sprigg married Patricia Day who had been born in Wiltshire, England and relocated to Adelaide with her parents during 1927. During 1943, she graduated as a BA (Adelaide), scoring first place in Political Science and worked in the History School during 1945 and 1946 reading essays and lecturing. During 1948, Patricia, aged 25, left Adelaide on the P&O ship "Stratheden", arriving in London on 27 March 1948. In London she worked at Magazine of the Future whilst reading law at Lincoln's Inn. Reg and Patricia divorced during 1950 and she moved to Sweden in 1951 to marry Gillis Een.
On 3 February 1951, Sprigg married Griselda A. Findlay Paterson, daughter of Robert Findlay Paterson and Grace née Dreghorn, born December 1921 in Paisley, Scotland. Griselda had studied in Glasgow and qualified as a radiographer.
During 1948, Reg, still with the South Australian Mines Department, was in Britain in association with uranium on behalf of the government; Griselda has said that she met Reg "on ...the island of Arran, .... Well there was I with three nursing sisters I’d held up with, and as I walked out of the restaurant that night, they stopped me and said, ‘I bet you can’t get a date with the Australian before midnight tonight, for tomorrow. I said ‘How much is it worth’, they said ‘five quid’, and I said ‘that’ll do me’. I got the five quid, got the date, and I always say, I won him in a bet."
During 1952, a daughter, Margaret and during 1954, a son, Douglas were born in South Australia.
Griselda and the children often accompanied Reg in his outback travels. During 2001, Griselda published an account of those travels in Dune is a four-letter word.
Reg Sprigg died on 2 December 1994 whilst on holiday in Glasgow, Scotland. His ashes were scattered at Arkaroola.
Griselda Sprigg died 20 March 2003.During 1980, he was awarded an honorary doctorate of science by the Australian National University.
During 1982, he was the inaugural Lewis G Weeks Medalist awarded by the then Australian Petroleum Exploration Association. Reg had been foundation president during 1959 of the association. The association has renamed its Gold Medal for "highly valued contributions within or for the Australian oil and gas industry or through sustained, notable leadership within APPEA" in his honour.
During 1983, he was made an Officer of the Order of Australia.
During 1986, he was the recipient of the Royal Society of South Australia's Verco Medal; at age 17, he had been the youngest fellow of the society.
During 1990, Flinders University conferred on him the honorary degree of Doctor of Science.
During 1998, the Geological Society of Australia, South Australia Branch initiated the biennial Sprigg Symposium "in recognition of the contributions Dr Reginald Sprigg made towards many aspects of geology in South Australia".
During 2001, the University of Adelaide announced that it had established the Reg Sprigg Chair in Petroleum Engineering in the (now) Australian School of Petroleum.
The genus Spriggina has been named in his honour.
The mineral Spriggite, a uranyl hydroxide mineral, has been named in his honour.
The annual Sprigg Lecture Series is held by the South Australian Museum to commemorate his discovery of the Ediacara fauna.
The main-belt asteroid 5380 Sprigg, discovered by Robert McNaught at the Siding Spring Observatory in 1991, was named in his honour.