Interior Secretary Ryan Zinke Ryan Keith ZinkeTrump extends Florida offshore drilling pause, expands it to Georgia, South Carolina Conspicuous by their absence from the Republican Convention Trump flails as audience dwindles and ratings plummet MORE has often referred to himself as a geologist despite never having worked as one after college, according to an analysis by CNN published Tuesday.

Zinke has suggested he is a geologist or former geologist more than 40 times in public since taking office, including while under oath on Capitol Hill, according to CNN.

He often uses the credential to justify his decisions while leading a 70,000-employee agency in charge of the nation’s federal lands and natural resources.

ADVERTISEMENT

"I can tell you, from a geologist, offshore mining of sand is enormously destructive environmentally, as in comparison to seismic," Zinke said at a House Natural Resources Committee meeting last month, according to CNN.

CNN also reported that Zinke has touted the job title while discussing such issues as climate change, coal revenue, national monuments, precious metals, endangered species, fracking and drilling.

Zinke does hold a bachelor's degree in geology from the University of Oregon, but CNN wasn't able to find evidence that he had actually worked in the field of geology since graduating.

"He seems not to be familiar with modern geologic knowledge," Seth Stein, a professor at the Department of Earth and Planetary Sciences and Institute for Policy Research at Northwestern University, told the news outlet.

In his autobiography, “An American Commander,” Zinke wrote that he chose his major at random since he was at the school on a football scholarship.

"I studied geology as a result of closing my eyes and randomly pointing to a major from the academic catalog, and I never looked back. I am just glad I did not find electronics," he wrote.

After his 1984 college graduation, Zinke served as a Navy SEAL commander.

He was elected to the Montana state Senate in 2008 and the U.S. House of Representatives in 2014.

Interior spokeswoman Heather Swift gave CNN a statement regarding Zinke's credentials.

"Ryan Zinke graduated with honors with a B.S. in Geology. His intended career path was underwater geology — and he had college jobs to support that career. Upon graduation he was recruited to be an officer in the US Navy SEALs where he proudly served for 23 years and retired with the rank of Commander," she said.

The Interior Department did not respond to a question from CNN about whether Zinke had ever been a member of the American Institute of Professional Geologists or the Association of State Boards of Geologists.

In January, President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE nominated James Reilly, a former astronaut and oil exploration geologist, to lead the U.S. Geological Survey under the Interior Department.