TY - JOUR AB - AU - Samuel Calvin, A. G. Leonard, William Harmon Norton, J. B. Weems DA - 1902/1// DO - 10.17077/2160-5270.1269 IS - 1 VL - 12 PB - Iowa Geological Survey PY - 1902 TI - Administrative Reports T2 - Iowa Geological Survey Annual Report UR - https://pubs.lib.uiowa.edu/igsar/article/id/1041/ ER -