Whetstone grave markers and Henry Cross markers will be studied at 2 p.m. May 30 at the Seymour Library.

Richard L. Powell, research affiliate of the Indiana Geological Survey, will present information on the mystery regarding gravestones quarried only in Orange County, Ind., in the early to mid-1800s but still found throughout southern Indiana (including some in Jackson County), Illinois, New Orleans and even Europe.

Call 812-522-3412 ext. 243 to register by noon May 28.

More than a decade ago, IGS researcher Powell became intrigued by this mystery. He also will discuss the early Brown County stone carver, Henry Cross, whose work also is found nearby.

For more information, call Charlotte Sellers at 522-3412 ext. 240.