1. Department of Geology and Geophysics; Boston College; Chestnut Hill; Massachusetts; USA
2. Department of Geosciences; Pennsylvania State University; University Park; Pennsylvania; USA
3. Departments of Geology and Geography; University of Illinois at Urbana-Champaign; Urbana; Illinois; USA
4. School of Earth and Environment; University of Leeds; Leeds; UK
5. Department of Geosciences; University of Nebraska at Lincoln; Lincoln; Nebraska; USA