Hydrogeology CdiConcepts and Exercise

Brought to you by Core Kids, WMUWMU--MGRREMGRRE Geosciences K -12 Outreach Program

With generous support from: In this presentation and datadata--basedbased exercise students will:

„ Learn about a critical natural resource - water „ Learn about the science used by the professionals who manage our water resources. „ Learn about the subsurface geology of Michigan andhd that of fhil their loca le „ Learn to access public databases on natural resources compiled by the State of Michigan Hydrogeology Concepts

„ The water cycle or hyygdrologic cycle shows the continuous movement of water on, above, andbd be low the Earth’s surface. Hydrogeology Concepts

„ Hydrology is the scientific study of the properties, distribution, and effects of water on the earth's surface, in the soil and underlyyging rocks, and in the atmosphere. „ Hyygdrogeolog ists study the distribution and movement of water below the Earth's surface, especially the distribution of groundwater, it’s flow, and ground water quali ty. Hydrogeologists & Hydrologists In Action Hydrogeology Concepts

„ Hydrogeologists need to understand what is under the ground surface in Michigan to know more about groundwater supplies here. „ Michigan is underlain by thousands of feet of bedrock, but most drinkinggpp water supplies are found in the uppermost few hundred feet. „ Geologic storage locations holding water are termed aquifers. Glaciers Shaped Michigan’s Surface

Adapted from Charles Barker, 2005 Layers of Rock Layers of Rock Depth in Feet of the Grand Canyon Under Michigan Below the Surface Grand Canyon Rock -0 -1,000 Layer Thickness vs. - 2,000 Michigan Bedrock - 3,000 - 4,000 Thicknesses -5,000 - 6,000 - 7,000 - 8,000 - 9,000 - 10,000 - 11,000 - 12,000 - 13,000 - 14,000 - 15,000 Bedrock Layers Deposited Prior to Glaciation

„ The bedrock of Michigan was deposited ibihihin a basin which appears similar to as set of nested bowls .

Adapted from Olcott, 1992 , and Modified from S. E. Wilson, 2006 modified from Robinson, 2004 Hydrogeology Concepts

„ Hydrogeologists study rocks and their properties to understand how water moves underground. „ These properties include: „ Consolidated vs. unconsolidated aquifer material „ TdhfhikihifType and shape of the grains making up the aquifer „ How the material affects water flow „ Potential environments of deposition SESome Examp lfles of Unconsolidated Sediments

Medium Sand

Pebbles/Gravel Coarse Sand Clay

Very Fine Sand Fine Sand Silt When unconsolidated sediments become lithified they are called Consolidated Sediments or Rocks

IiInsert images from penn sand stones, etc.

Sandstone Siltstone Hydrogeology Concepts

„ Porosity is the amount of space between the grains of sediment in unconsolidated or consolidated aquifer materials . „ The amount of “pore space” is determined by the shape, size , and sorting of the grains and any cements holding the grains together. „ The greater t he pore space, t he more porous t he material is. Sediment Grain Shape Analysis Tool

From Jones & Jones, 2003 „ Grain roundness affects how sediments fit together when compacted or lithifi ed . „ Sorting is a measure of the distribution of different sized sediments in a material. „ Poorly sorted sediments have grains of many different sizes present. „ Well-sorted sediments have grains of similar sizes. „ Larger grai ns may “fl oat” i n a matrix of smaller grains. Hydrogeology Concepts

„ When the pores of a material are connected together, water and other fluids can flow through the material . „ The more fluids that can pass through the pores, the more permeable a material is. „ Rocks are porous, but may not be considered permeable depen ding upon t he c haracter ist ics o f t he pores and how they are connected. Sediment: Sand Rock: Sandstone Hydrogeology Concepts

„ Water stored in the pores of unconsolidated and consolidated material is affected by gravity and pressure. „ The water table level at any location is an example of these effects . „ Pollution is a major threat to the relatively shallow nature ofhf the water ta ble an d uncon fidfined aquif ers i n many parts of Michigan. From Jones & Jones, 2002 Hydrogeologic Vocabulary: „ Zone of aeration is where pores are filled mostly with air . „ Zone of saturation is where pores are filled with fluids. „ Water table is the boundary between the two zones . Hydrogeology Concepts

„ In Michigan, aquifers in unconsolidated, glacial sediments are termed unconfined aquifers. „ Easier to access, shallower „ More prone to pollution „ Bedrock aqqy,uifers are usually confined, or bounded by other rock units that do not allow as much or any water to pass. „ May be harder to access, but less easily polluted „ If too deep may be briny Glacial Sediments and Bedrock Aquifers

Modified from W. R. Farrand, 1982 Modified from the Institute of Water Research, 1987 From Jones & Jones, 2002 From Jones & Jones, 2002

Unconfined Aquifer Confined Aquifer Hydrogeologic Vocabulary: „ Pumping wells affect the water in the pores of the aquifer surrounding them forming a cone of depression. „ IfiddiiIn confined conditions, water pressure f rom rech hiarge in higher elevation areas can force wells to flow aboveground in lower-lyyging areas. „ These are called artesian wells or springs. Hydrogeology Concepts

„ Once hydrogeologists understand the aquifer material and the general geology of the area, they may assign an environment of deposition to the materials making up the aquifer. „ This understanding may give them clues about water qqy,qy,uality, quantity, and availability . Depositional Environment Affects Aquifers Example

„Deltaic deposits can be sandy or muddy and are home to many kinds of plants. „Lithification turns sands to sandstone , and muds to mudstone and siltstone. „The sandstones may be good water-bearing source rocks. „The mudstones and siltstones may be barriers to water flow. „Organic material trapped ihin the roc kfks from swampy areas may cause poor water qqyuality from the release of gases from decayed vegetation. Humans Contaminate Groundwater in Many Ways

From Jones & Jones, 2003 Humans Contaminate Groundwater in Many Ways

An illustration of salt-water encroachment, this can also occur in areas whdhere deep bdkbedrock aqui fers are b riny, lklike in Michigan’s rock formations deposited from seas. Exercise: Water Wells & Lithology

Brought to you by Core Kids, WMUWMU-- MGRRE Geosciences K-K-1212 Outreach Program

Exercise created by Niah Venable, Amanda Walega and SGSusan Grammer w ithbttbNihVblith web content by Niah Venable A special thanks to 8th grade teacher Becky Dalecki, Portage North Middle School and to the 8th grade sci ence t each ers and st ud ent s at M att awan Middl e S ch ool .

With generous support from: This exercise can be adapted for:

„ High school students wishing to do an independent project using real data from their local area. „ Middle school students whose teachers can lead them through accessing data and constructing stratigraphic columns as a class according to the instructions on this website. „ Later elementary students who can use this exercise to visualize what is underground in their area. Exercise Steps

1. Choose an area of interest (e.g. Charlotte, MI) 2. Find the corresponding topographic map 3. Find water well data from the area of interest 4. Interpret water well driller’s logs 5C5. Create lihllitholog ic co lumns 6. Calculate the Well Elevation 7. Create stratigraphic columns 8. Create cross-cross-sectionssections for comparison 1. Pick an Area of Interest

„ For this example we will look at water wells around Charlotte, MI. „ Charlotte is located in Eaton County . „ First we need to get a topographic map of the area near Charlotte . This map will give us political and landform information such as section numbers and elevation contours for use in this project. 2. Find a Topo Map

„ Browse to the State of Michigan, Department of Natural Resources homepage: www.michigan.gov/dnr „ From there browse to Publications and Maps, then Online Maps. Go to Topographic Quadrangles by Location. „ Use the dropdown list to find the county, in this case it is Eaton. A quick link to this page is: www.michigan.gov/dnr/1,1607,7www.michigan.gov/dnr/1,1607,7-- 153153--10371_1479310371_14793--3126431264----,00.html,00.html „ Cliccwd.k Download. 2. Find a Topo Map cont.

„ The ne xt screen sho ws a green and yellow version of a political map with the locations of cities and towns with a blue grid overlay of the qqguadrangle names. „ Click on the quad labeled “Charlotte” in Eaton and ClCarmel towns hips. 2. Find a Topo Map cont.

„ A pdf of the Charlotte quadrangle will open in Adobe Acrobat. We can save this and use asas--isis or copy and zoom to a portion of the map using MS Word or imaggge handling software. 3. Find Water Well Data

„ Browse to the State of Michigan, Department of Environmental Quality homepage: www.mihiichigan.gov /deq „ From there click Water, then browse to Drinking Water, to WtWater W WllCell Cons tructi on, th en click on Scanned Water Well Record Retrieval System. „ AikliktthiA quick link to this page i s: www.deq.state.mi.us/wellwww.deq.state.mi.us/well--logs/logs/ 3. Find Water Well Data cont.

„ The information used to find the topo and the map itself provide the county, township and section data we need to search the well retrieval database. „ We are interested in Eaton CnttCounty so two sear rhndches need to be done by township, one for Eaton in sections 6, 18 and19d 19; and one f or C armel in sections 12, 13, and 24. We will omit section 7 of EtEaton t ownshi p, d ue t o an absence of usable logs. 3. Find Water Well Data cont.

„ After selectinggy, the county, township(s) and section(s) of interest, we will be able to review a pdf file containing the scanned images of driller ’ s reports from each area. „ The pdf driller ’ s reports or logs will look like this. The number of logs available for each section varies. 4. Interpreting Driller ’s Logs

„ The driller ’ s log header contains well location information and often a handhand--drawndrawn map with street names, which may prove useflifhful if the quarterquarter--quarterquarter location information is not recorded, or recorded incorrectly. 4. Interpreting Driller ’s Logs cont.

„ The driller’s log lithology information is listed by type of material, thickness of each unit, and total depth. The formation descriptions are more likely to be generic than scientific. „ The total drilled depth of this well is 100 feet blbelow the su rface. 4. Interpreting Driller ’ s Logs cont.

„ Other information provided by the driller ’ s log is the owner of the well, the depth, the completion date and how the well was completed. „ It will also list possible sources of contamination , pump type, and who drilled the well. „ The static water level is equal to the depth to the water table, in this case it was encountered 36 feet below the surface. 5. Creating Lithologic Columns

„ Lith ol ogi c or strati graphi c columns can be created from driller’s logggs using

the formation descriptions „ From 00--1212 feet below the surface the provided by the driller and driller encountered clay. the d epth s t o and th e „ F1216fblhfFrom 12 to 16 feet below the surface thicknesses of each unit. they found sand. „ From 16 to 54 feet below the surface thfhey foun dld clay. „ From 54 to 60 feet below was gravel. „ From 60 to 100 feet below the surface they found “sandrock”, most likely the sandstones of the Saginaw Aquifer. 5. Creating Lithologic Columns cont.

„ A basic form created in Excel is useful for plotting lithogy and other well in form a tion f or viewing as a lithologic or stratiggpraphic column. „ The lithologic key can be modified depending on thfhilhe type of earth material encountered in the wells. 5. Creating Lithologic Columns cont.

Hammond „ Usinggg the driller’s log depths below the surface as a guide, we plot the lithol ogi c t yp es on th e column with the lithologgypic key patterns and colors as fill. „ Next, we mark the water lllevel on th e co lumn using the symbol from the key. 6. Calculate the Well Elevation

„ To calculate the well elevation values in feet above sea level and to convert the lithogic column to a stratigraphic column, we must first determine the well surface elilevation. „ This is done using a topographic map s ince mos t of th e drill er’ s reports do not provide well elevations. 6. Calculate the Well Elevation cont.

„ Usinggpp the topo map of Charlotte and the location information provided in the driller’s report we fin d tha t th e exampl e well i s located here. „ Contour lines in this area range between 910 feet and 920 feet above sea level. Interpolating thlhe locat ion between t he two contours gives us a value of 918 feet above sea level. 6. Calculate the Well Elevation cont.

„ We record the well elevation in the blank to the right. And then place the valthtlifthlue on the top line of the scale on the right side of the lithology column . „ Next we subtract the depths in ten foot inc re me nts fro m the elevation value until the bottom of the well is reached. 7. Create Multiple Strat Columns

„ To compare the hydrogeology from several wells around the Charlotte area we must create more stratiggpraphic columns. „ Repeat steps 3 through 6 to create these columns. „ For this example we will use driller ’ sslogsfrom logs from Eaton township, sections 18 and 19, and Carmel township, sections 12 , 13 , and 24. „ We will mark the locations of all the wells on the topo map for reference. 7. Multiple Strat Columns cont.

Hammond

„ All of the wells are now marked on the t opogra phi c ma p f or reference. Mishler „ Well elevation values have been Burt picked from the map and used to

convert the lithologic columns to Porter stratigraphic columns.

Archer

City 7. Multiple Strat Columns cont.

„ Well Name and Elevation Range: „ Once the stratigraphic Hammond: 918918--818818 ft. columns are created, a Burt: 890890--790790 ft. depppth datum is picked. City: 912 -872 ft . „ The depth datum is used Archer: 895895--775775 ft. to comppgyare the lithology Porter: 900900--800800 ft. and water levels in all Mischler: 945945--835835 ft. wells at corresponding „ The depth datum should be dhdepths. 880 f eet ab ove sea l evel si nce all wells intersect that depth. 8. Cross-Cross-SectionSection Creation

„ The geographic area B covered by the wells can be divided into two

cross-sectional lines A running approximately North to South „ They are labeled A to A’ and B to B’.

A’

B’ 8. Cross–Section Creation cont. „ The wells in each crosscross--sectionsection can be compared by lining them up on the datum value .

880 ft. A A’

~ 1.5 mi.

~ 1 mi. 8. Cross–Section Creation cont. „ It is important to remember the distances between wells when making cross -sectional comparisons .

880 ft. B B’

~ 2 mi. ~ 1.75 mi. 9. Interpretation „ The cross-cross-sectionssections combined with the well lilocations on th e topo map g ive a spat ilial comparison of the earth materials encountered at dhdhhdepth and how those mater ilials vary over a distance between wells. „ The wells are about 1 to 2 miles apart and the relief between the highest and lowest wells is 55 feet. Static water levels range between a max elevation just under 900 ft. to just over 875 ft. 9. Interpretation cont.

„ The glacial sediments found above the sandstone and shale bedrock in this area show variation in type and thickness from w ell to w ell, which is typical of these kinds of materials. „ Generallyyg,g though, the glacial dep osits in the AA-- A’ wells consist of clay and gravels, while the deposits in the BB--B’B’ wells are mainly sand and clay. 9. Interpretation cont.

„ The Charlotte wells show no significant variation in static water levels. Dramatic variations in static water levels could be due to draw down effects in heavyheavy--useuse areas. „ The sandstone and shale bedrock elevations vary by 60 ft for all wells, but for each cross section, the variation is between 25 -45 feet . 10. Summary

„ Topographic maps and water well driller’s lbdihlogs can be used to examine the nearnear--sursurface geology of Michigan. „ The driller’s logs are also useful for determining depth to the water table, potential nearby contamiihination hazar ds, an dhifd other informat ion. „ The data needed for these exercises is readily availabl e on t he internet from State o f Mic higan sources.