Mortimer D. Turner, 83, a geologist who helped open the Antarctic to scientific research and who oversaw Arctic research from the 1960s to the mid-1980s, died of a seizure May 1 in Boulder, Colo., where he lived.

Dr. Turner, program director for polar earth sciences for the National Science Foundation in Washington, helped move polar research from geographic exploration into the broader science fields by choosing research teams, directing grants and projects and advancing interest in the polar regions. He made 27 trips to the Antarctic over the years.

"His biggest impact on polar research was his work with his grantees," said his wife, JoAnne Church Turner, who worked with him. "Because the Antarctic had never been explored, it was important that grantees did not go only with their own project in mind, but that they go and see all kinds of science. He encouraged them to be broader in their thinking."

One young scientist, on a project launched by Dr. Turner, discovered a fossil of a lystrosaurus, a mammal-like reptile previously found in South Africa, India and Australia. Because the animal could not cross fresh or salt water, its discovery in Antarctica was said to contribute to the proof of "continental drift," or the existence of Gondwanaland, the large continent that is theorized to have preceded the existence of Australia, Antarctica, India, South America and South Africa.

In 1968, Dr. Turner oversaw the first drilling project to completely penetrate the Antarctic ice sheet's core. The results from that study and from sediment drilling and meteorite collection projects allowed scientists to study evolution, earth structure and signs of global climate change in differing layers of the ice.

As a colleague, he was "gracious, generous, dignified and knowledgeable, and he seemed mostly unfazed by the short-fuse panics that occasionally dominated our work," said Guy Guthridge, the National Science Foundation's manager of Antarctic information in the Office of Polar Programs, who worked with him for 14 years. "For him, his investigators were his stars. He wanted them to get credit." Although he was willing to forgo credit for ideas, he enjoyed brainstorming with polar-bound teams, his wife said.

"A lot of this was done around our dinner table. In the early days, the geologists or scientists went down by military air transport out of Washington, and lots of times, people would stay at our house [in Kensington], instead of at a hotel, to save money," she said.

"The interaction of the people was fascinating. . . . He told people, 'Keep your eyes open for the unusual, keep your eyes open for the difference.' What was important to him was the science. The challenge to him was science," she said.

He decided to donate his body to science. After an autopsy of his brain is completed, "then he will become a cadaver. Which I think he will enjoy," his wife said.

Dr. Turner was born in Greeley, Colo., and graduated from the University of California at Berkeley in 1943 with a bachelor's degree in geological engineering. During World War II, he served in the Army as a technician in the Ordnance Department. After his discharge, he spent three months as an engineer on missiles under Edwin Hubble at the Aberdeen Proving Ground.

He worked as a mining geologist at the California Division of Mines from 1948 to 1954, during which time he received a master's degree in geology from Berkeley. He went to Puerto Rico to serve as the state geologist. Five years later, he was recruited to become assistant to the program director of the newly established U.S. Antarctic Research Program.

Dr. Turner received a doctorate in geology and metallurgical engineering from the University of Kansas in 1964. Upon his return to the National Science Foundation, he was given responsibility for the Arctic as well as the Antarctic. He published more than 70 scientific papers.

He retired in 1984 to do research in geology and early humans in Colorado, Montana and China. In 1987, he moved to Boulder to join the University of Colorado's Institute of Arctic and Alpine Research, where he and his wife continued research. He also taught geology courses at the University of Colorado at Denver.

The Turner Hills in Antarctica were named for him by the U.S. Board on Geographic Names. His name also adorns the mineral Turnerite from the Ice Free Valley area of South Victoria Land, a fossil of an Oligocene sirenian skull called Caribosiren turneri and a Cretaceous marine reptile fossil Morturneria seymourensis.

The American Polar Society gave him its Career Service Award last year. In 1995, he received an award from the Center for the Study of the First Americans at Oregon State University for contributions to understanding America's earliest cultural heritage.

His wife of 20 years, Laura Perez Mendez, died in 1965.

Survivors include his wife of 38 years, JoAnne Church Turner of Boulder; three children from the first marriage, Satia Goff of Monticello, Minn., Ylla Romdall of Bellingham, Wash., and Robert Turner of Bakersfield, Calif.; a stepson, Christopher Dort of Spotsylvania, Va.; six grandchildren; and three great-grandchildren.

Dr. Turner of the National Science Foundation told polar researchers to think broadly. "His investigators were his stars," a colleague said.