NEBRASKA WELL DRILLERS ASSOCIATION
CONSERVATION AND SURVEY DIVISION, SCHOOL OF NATURAL RESOURCES NORTHEASTERN NEBRASKA GEOLOGICAL FIELD TRIP
October 19, 2017
Originating at South Sioux City, Nebraska
(approximate schedule: note that tour may run as much as one hour over scheduled time of
7:45-800am Registration and check-in at the Marina Inn (385 East 4th
SSC) Brief introduction to trip
8:00-8:30am Leave South Sioux City and proceed into Sioux City, Iowa, thence north northwest to Stone State Park, Iowa.
8:30-10:00 Stone State Park, Iowa
: Overview of regional Cretaceous bedrock stratigraphy and examination of Dakota Formation as basal unit of regional Cretaceous succession. Discuss Dakota Formation as secondary aquifer in eastern Nebraska (recent geologic investigation includes three new test holes through the Dakota Formation near Winnebago, Jackson, and Hubbard, Nebraska), as well as in Iowa. Discuss revision of Papio Missouri River NRD Groundwater Management Plan and Groundwater Rules and Regulations, which include modified triggers for groundwater quality and quantity. Return to South Sioux City by outbound route and continue to Ponca State Park in Nebraska (extend discussion of subjects enroute to next stop as necessary).
10:00-12:00pm Ponca State Park and lunch stop
: Examine exposures of upper Dakota Formation through Greenhorn Limestone and discuss stratigraphy, rock types, recognition in subsurface, depositional environments, and hydrogeologic significance. Briefly discuss geomorphology and hydrology of Missouri River. Continue discussion during lunch.
12:00-12:30pm Drive from Ponca State Park to Volcano Hill, northeast of Newcastle, Nebraska.
12:30-1:00pm Volcano Hill near Newcastle Nebraska: Examine exposures of Carlile Shale and discuss stratigraphy, rock types, recognition in subsurface, depositional environments, and hydrogeologic significance. Discuss Codell Sandstone aquifer in detail. Discuss, and examine evidence for, near-surface oxidation of pyrite by percolating waters (acid rock drainage) and its potential impacts on mineral formation and water chemistry, as well as the history of the so-called "Ionia Volcano."
1:00-1:30pm Drive to vicinity of Bow Valley, Nebraska.
1:30-3:00pm Bow Valley-Hartington-St. Helena. Nebraska area: View and discuss local landscape and its relationship to surficial sediments and Pleistocene glacial, eolian, and fluvial processes. Examine exposures of Niobrara Formation and discuss stratigraphy, rock types, recognition in subsurface, depositional environments, and hydrogeologic significance. Discuss Niobrara aquifer in detail. Briefly discuss overlying Pierre Shale (uppermost stratigraphic unit in regional Cretaceous succession) and overlying Neogene strata of Ogallala Group relative to characteristics and extent of High Plains aquifer.
3:00-4:00pm Return to South Sioux City and conclusion of tour. Participants will be required to complete a field-trip related exercise on return trip
. Completion of tour and sign out. Note that tour may run as much as one-hour overtime.
Objectives of tour
: This tour will summarize the regional geology and hydrogeology of a large portion of northeastern Nebraska. In the course of the tour, participants will examine Cretaceous and younger (Miocene-Holocene) strata in the contexts of regional stratigraphy, hydro stratigraphy, and geological history. Participants will learn to recognize bedrock and sediment units and place them in a vertical stratigraphic sequence. Significant emphasis will be placed on understanding aquifers hosted in bedrock (Dakota, Codell, and Niobrara aquifers). The tour will also elucidate surficial sediments, Pleistocene-Holocene landscape history and regional geomorphology and surface and shallow groundwater hydrology. Geology and hydrogeology will be placed in the context of current management efforts and concerns.
R. M. Joeckel: Associate Director for Conservation and Survey in the School of Natural
Resources, Professor in School of Natural Resources and Department of Earth and Atmospheric Sciences, and Curator of Geology, University of Nebraska State Museum (Ph.D., Geology, University of Iowa, 1993).
D. P. Divine: Survey Hydrogeologist, Conservation and Survey Division, School of Natural Resources, University of Nebraska-Lincoln (M.S., Geology, Washington State University, 2002).
P. R. Hanson: Associate Director, School of Natural Resources, Professor in School of Natural Resources (Ph.D., Geology, University of Nebraska, 2005).