1. 1 University of Oklahoma, School of Geosciences, Norman, Oklahoma 73019, U.S.A.
2. 2 Rowan University, Department of Geology, Glassboro, New Jersey 08028, U.S.A.
3. 3 University of Bristol, School of Geographical Sciences, Bristol, U.K.
4. 4 Independent Geoscientist, Norman, Oklahoma 73072, U.S.A.