TY - JOUR AB - AU - J. A. Udden DA - 1902/1// DO - 10.17077/2160-5270.1274 IS - 1 VL - 12 PB - Iowa Geological Survey PY - 1902 TI - Geology of Jefferson County T2 - Iowa Geological Survey Annual Report UR - https://pubs.lib.uiowa.edu/igsar/article/id/1039/ ER -