Matthew Lachniet doesn't have your typical desk job.  When he goes to work, he dons a head lamp and climbs into the deep recesses of some of the world's oldest caves.  The UNLV geologist talks about his recent trip to a Mexican cave for National Geographic, and his groundbreaking find with a 2400-year-old stalagmite.

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Matthew Lachniet, Assoc Prof of Geology, UNLV