Balaban, N.H., Editor2010-03-102010-03-1019870192-6268https://hdl.handle.net/11299/59136PREPARED FOR THE 21 ST ANNUAL MEETING OF THE GEOLOGICAL SOCIETY OF AMERICA, NORTH-CENTRAL SECTION ST. PAUL, MINNESOTA, 1987CONTENTS KARST HYDROGEOLOGY OF SOUTHEASTERN MINNESOTA, E. Calvin Alexander, Jr. THE GEOLOGY OF THE ST. CROIX RIVER VALLEY, Mark E. Cavaleri, John H. MossIer, and Gerald F· Webers INTRODUCTION TO THE MIDDLE AND LATE ORDOVIClAN FIELD TRIPS, Robert E. Sloan THE MIDDLE ORDOVICIAN FOSSILS OF THE TWIN CITIES, MINNESOTA, Robert E. Sloan, William F. Rice, Eric Hedblom, and James M. Mazzullo THE MIDDLE AND LATE ORDOVICIAN STRATA AND FOSSILS OF SOUTHEASTERN MINNESOTA, Robert E. Sloan and Dennis R. Kolata THE MIDDLE AND LATE ORDOVICIAN STRATA AND FOSSILS OF IOWA, Dennis R. Kolata and Robert E. Sloan THE ROCK ELM DISTURBANCE, PIERCE COUNTY, WISCONSIN, William S. Cordua QUATERNARY GEOLOGY OF SOUTHEASTERN MINNESOTA, Howard C. HobbsengeologyUpper Mississippi ValleyMinnesota Geological Surveykarstfossilscarbonate rocksMap