Geology, Ecology, and Geology, Ecology, and Resources of Iowa Resources of Iowa

By Danielle JannuschBy Danielle Jannusch

Welcome to the Welcome to the Hawkeye StateHawkeye State

• Iowa was a tremendous geologic and ecologic history. This presentation will discuss:– Geologic Feature: Devonian Fossil Gorge– Ecologic Feature: Iowa Prairie– Renewable and nonrenewable resources of

Iowa

Iowa GeologyIowa Geology

http://www.igsb.uiowa.edu/browse/geoiowa/geoiowa.htmhttp://www.igsb.uiowa.edu/service/geology.htm

Iowa Geologic historyIowa Geologic history• The oldest rocks in Iowa are buried deep underground.• Most of Iowa’s geologic history is written in sedimentary rocks, such as sandstone,

limestone, dolomite and shale, which are over 3,000 feet thick in places. (DNR, 2010)• Iowa sedimentary rocks originated as layers of loose sediment accumulating in

shallow seas and along coastal and floodplain environments between 74 million years ago (Cretaceous) and 530 million years ago (Cambrian).

• Over time, this sediment was lithified into rock containing fossil remains of past animal and plant life.

• Fossiliferous sedimentary rocks are found among the abundant outcrops of northeastern, eastern, and central Iowa

• Most sedimentary rock exposures in Iowa are found along river valleys, at roadcuts, and in quarries.

• Since most of our geologic history is buried, most of our knowledge comes from rock samples brought up to the land surface during the drilling of wells.

• The oldest known formation in Iowa the Otter Creek Mafic Complex (about 2.95 billion years old), the youngest is the Wisconsinan glacial drift (about 10,000 years old). (DNR, 2010)

• Additionally, river sediments that are still being deposited today.

Iowa Stratigraphic Iowa Stratigraphic Column:Column:

This column shows all This column shows all the different rock types the different rock types found on the surface found on the surface and in the subsurface and in the subsurface

of Iowa terrain Column. of Iowa terrain Column. This column has been This column has been used to correlate Iowa used to correlate Iowa rocks with sedimentary rocks with sedimentary strata throughout the strata throughout the

Midwest and the Midwest and the countrycountry

Source: http://publications.iowa.gov/4862/1/EM-40.pdf

Geologic Feature: Geologic Feature: Devonian Fossil Devonian Fossil

GorgeGorge• Discovered during the Flood of 1993

when floodwaters from Coralville Lake came over the spillway eroded away 15 feet of glacial-age sediments to expose 375-million-year old fossiliferous bedrock.

• The rocks of the gorge: The dominant rock type at Devonian fossils gorge is fossiliferous limestone. The limestone is rich in crinoids, corals, stromatoporoids and several species of brachiopod fossils.

• Limestone is comprised of calcite.• History of the sediments: These

sediments were deposited during the Devonian Period about 375 million years ago, when eastern Iowa was covered with a shallow sea. The fossils suggest that this was a reefal normal marine environment with a moderate undercurrent (Prior, 1998)

A recreation of the Devonian of Iowa

1993- The fossil sea is discovered after the flood of 1993

Newly designed entrance to the Gorge

http://www.igsb.uiowa.edu/browse/spillway/spillway.htm

How has plate tectonics affected How has plate tectonics affected the Gorge?the Gorge?

• Current earthquake activity: Only 13 earthquakes with epicenters in Iowa are known in historic times. The first known occurrence was in 1867 near Sidney in southwest Iowa; the most recent occurrence was in 2004 near Shenandoah in SW Iowa. The largest Iowa earthquake (Mercalli magnitude VI) occurred near Davenport in southeast Iowa in 1934. (DNR, 2010)

• Activity around the Gorge is rare, but some of the strata are inclined.

• Looking north toward the Coralville Lake Spillway some of the limestone strata are inclined and domed. (DNR, 2010)

• It has been suggested that this inclination may be the result of irregular settling of the sedimentary layers when they were still soft, or the result of much later, broad-scale warping of rock units across the Midwest.

• Small geologic faults are also exposed here, with vertically displaced strata and tiny gouges along the rock faces indicating movement in the geologic past (about 310 million years ago) (Prior, 1998)

•http://www.igsb.uiowa.edu/Browse/earthqua/iowa_quakes.htm

Glacial and Surficial Processes and Glacial and Surficial Processes and their impact on Iowatheir impact on Iowa

• Glacial processes are responsible for many of the geologic features throughout the state.

• The “lake district” area of northern Iowa is dominated by natural lakes and bogs, among irregularly shaped hills, and in the boulders- all evidence of glacial activity (Anderson and Prior, 2010)

• This region is called the "Des Moines Lobe," Its name refers to the location of Iowa's capital city at the southernmost limit of this former ice mass. (Harr et al, 2010)

• The geologically fresh deposits of the Des Moines Lobe still display the special landscape shapes that result from direct contact with melting and disintegrating glacial ice. (Anderson and Prior, 2010)

• The Flood of 1993 was the defining erosional process that uncovered Devonian Fossil Gorge. Moderate wind and water erosion is responsible for the current weathering of the Gorge. Acid rain leads to chemical weathering of the Gorge’s limestone.

http://www.igsb.uiowa.edu/Browse/glatrail/glatrail.htm

Iowa EcologyIowa Ecology

http://www.igsb.uiowa.edu/portrait/3change/Change.htm

Ecological feature: Iowa PrairieEcological feature: Iowa Prairie

• Iowa had the largest percentage of its area covered by tallgrass prairie - 30 million acres before European settlement (IAN, 1998)

• Now, only 0.01% of the original prairie is left• Iowa prairie originated nine to ten thousand years ago,

following the retreat of Iowa’s most recent glaciers. (IAN,1998)– Prairies formed in much of north and central Iowa due to warm,

dry climatic conditions

• Once established, prairie plants held their ground. The dense roots of prairie plants did not allow invading trees and shrubs to grow. (IAN, 1998)

Plants and Animals in the Iowa Plants and Animals in the Iowa Prairie (IAN, 1998)Prairie (IAN, 1998)

• Plants (Autotrophs):– Big bluestem– Grasses: Indian grass, Code

grass, Switch grass– Wildflowers: Compass plant,

black-eyed Susan, lead plants, prairie coneflower

• Wildlife (Heterotrophs):– Bison, elk, antelope, wolves,

prairie dogs, red fox, coyote, moles, shrew

– Birds: meadowlark, red-tailed hawk

– Insects: spittelbugs, ants, grasshoppers

– Reptiles and amphibians: ornate box turtle, western hognoose snake

http://www.nps.gov/archive/wica/images/Big_Blue_Stem.jpghttp://www.nps.gov/wica/naturescience/images/Prairie-Coneflower.jpghttp://www.naturehills.com/images/productImages/black_eyed_susan_goldstrum_1.jpg

Food web Food web in an Iowa in an Iowa

PrairiePrairie(arrows in the (arrows in the

direction of energy direction of energy flow)flow)

http://www.nps.gov/archive/wica/images/Big_Blue_Stem.jpghttp://www.naturehills.com/images/productImages/black_eyed_susan_goldstrum_1.jpghttp://www.nps.gov/wica/naturescience/images/Prairie-Coneflower.jpg

Endangered/Exploited species in Endangered/Exploited species in IowaIowa

• In Iowa, Chapter 481B of the Code of Iowa protects endangered species

• Violations of the provisions of Chapter 481B for threatened or endangered species are misdemeanors punishable by a fine of up to $100.

• Complete list: http://www.iowadnr.gov/wildlife/files/wildinfo.html

http://www.iowadnr.gov/other/threatened.html

Iowa Pleistocene land snail

Higgins eye pearly mussel

Osprey

Western prairie fringed orchid

Local biodiversityLocal biodiversity

• Iowa’s landscape and biodiversity have changed drastically over the past 150 years and the prairie has been destroyed (IAN, 1998)

• Alteration and redirection of many Iowa streams has caused a decrease in the marshland and marshland communities throughout the state

• Pollution and land clearing are the major forces that have changed Iowa’s biodiversity (IAN, 1998)

Renewable and Renewable and Nonrenewable resources of Nonrenewable resources of

IowaIowa

Mineral/ Rock ResourcesMineral/ Rock Resources

• Most of the mineral resources in Iowa are used for construction and building materials Examples are:– Clay and shale– Crushed limestone– Gypsum– Cement– Sand and gravel

• These minerals and rocks are extracted from quarries throughout the state

http://www.igsb.uiowa.edu/Browse/gypsum/gypsum.htm

Nonrenewable Nonrenewable resources found in resources found in

Iowa: CoalIowa: Coal• Small quantities of coal were first mined in

the 1840's near Fort Des Moines and along the lower Des Moines River (Coal, 2002)

• In 1854 the Rock Island Railroad reached the Mississippi River, and by 1860, 500 miles of track existed in Iowa. By 1876 the North Western Railroad reached Council Bluffs, and Iowa was the leading coal producer west of the Mississippi and fifth in the U.S. (Coal, 2002)

• By 1914 the state's rail network included 9,216 miles of track, and by 1918 annual coal production in Iowa peaked at 9.3 million tons.

• Production declined thereafter and the industry shifted from underground to surface mining operations. (Coal, 2002)

• By 1920, almost all Iowa coal mines had been shut down, in favor of mining the cleaner coal in Illinois. Mining operations shifted from coal to gypsum and limestone

Iowa’s renewable resourcesIowa’s renewable resources• The two major renewable energy sources

harvested in Iowa are wind energy and bioenergy and biofuels

• Wind energy– Iowa is the second largest producer of wind

energy in the US, just behind Texas. (IEC, 2010)

– Iowa has 3,670 MW of installed wind power which is enough to power approximately 1,125,000 homes (IEC, 2010)

– Wind energy is producing jobs in Iowa• Biomass/bioenergy

– Iowa has 31 ethanol plants in operation, producing approximately 2.54 billion gallons per year. (bottom picture)

– Iowa leads the nation in biofuels output accounting for 26 percent of U.S. ethanol and 12 percent of biodiesel production capacity (IARFA, 2010)

– Ethanol lowers harmful carbon monoxide (CO) emissions by 30 percent and reduced carbon dioxide (CO2) emissions by 27 percent. (IARFA, 2010)

– 11 landfills in Iowa that are candidates for electric generation (Bird et. al, 2005)

http://iowa.com/wp-content/uploads/2008/12/ilive-weather.jpg

Human impact on our resourcesHuman impact on our resources

• As humans it is our responsibility to conserve nonrenewable natural resources and replace nonrenewable resources with cleaner, more environmentally friendly renewable resources

• Going green can mean and increase in the number of jobs. In Iowa alone, ethanol and biodiesel production supported 83,000 jobs in 2008 (IARFA, 2010)

• Relying on alternate energy sources can cut our dependence on foreign oil , since wind energy and biofuels are produced right here in Iowa

ReferencesReferences• (2004) Stratigraphic Column of Iowa, 2004. Natural Resources, Department of.• Devonian Fossil Gorge photo: http://www.mvr.usace.army.mil/coralville/devonian_fossil_gorge.htm• Flood of 1993 photo: http://www.igsb.uiowa.edu/browse/flood93/flood93.htm• Gypsum photo: http://www.igsb.uiowa.edu/Browse/gypsum/gypsum.htm• (2002) Coal Geology of Iowa. 2002 Keystone Coal Industry Manual ®• Bedrock Geology map: http://www.igsb.uiowa.edu/browse/geoiowa/geoiowa.htm• (1995) Iowa Biodiversity. Iowa Association of naturalists • Iowa prairie map: http://www.igsb.uiowa.edu/portrait/3change/Change.htm• Bird, L. et. al (2005) Iowa Renewable Resource Assessment• Anderson, R.R. and Prior, J.C. (2010). Glacial Boulders in Iowa. Retrieved March 22, 2010 from

http://www.igsb.uiowa.edu/Browse/boulders/boulders.htm• Harr, D.C. et. al (2010). Glacial Landmarks trail: Iowa’s Heritage of Ice. Retrieved March 22, 2010 from

http://www.igsb.uiowa.edu/Browse/glatrail/glatrail.htm• Iowa Department of Natural Resources (DNR). (2010). General Geology. Retrieved March 23, 2010 from

http://www.igsb.uiowa.edu/service/geology.htm• Prior, J.C. (1998) Devonian Fossil Gorge. Iowa Department of Natural resources. Retrieved March 20, 2010 from

http://www.igsb.uiowa.edu/browse/spillway/spillway.htm• Iowa earthquake map: http://www.igsb.uiowa.edu/Browse/earthqua/iowa_quakes.htm• Iowa Energy Center (IEC) (2010). Wind Energy in Iowa. Retrieved March 24, 2010 from http://www.energy.iastate.edu/renewable/wind/• Iowa Wind Farm picture: http://iowa.com/wp-content/uploads/2008/12/ilive-weather.jpg• Big Bluestem picture: http://www.nps.gov/archive/wica/images/Big_Blue_Stem.jpg• Prairie cone flower picture: http://www.nps.gov/wica/naturescience/images/Prairie-Coneflower.jpg• Black-eyed Susan picture: http://www.naturehills.com/images/productImages/black_eyed_susan_goldstrum_1.jpg• Iowa Association of Naturalists (IAN) (1998). Iowa Prairies. Iowa Biological series. Iowa Association of Naturalists. (IAN-203)• Mole picture: http://www.allstateanimalcontrol.com/images/large%20images/moleBig.jpg• Iowa Renewable Fuel association (IARFA)(2010) . Ethanol Facts. Retrieved March 26, 20910 from

http://www.iowarfa.org/ethanol_facts.php