Can I ask if any one have ever seen such hexagonal cracks (about 1 to 2 cm in diameter) in marine marlstones?

Dear colleagues Good day. Can I ask if any one have ever seen such hexagonal cracks (about 1 t0 2 cm in diameter) in marine marlstones. I will be very much grateful if any reference or...

01 January 2019 5,016 18 View