hydrogeology cdiconcepts and exercise concepts and...hydrogeology concepts hydrology is the...

Hydrogeology Hydrogeology C d iC d iConcepts and ExerciseConcepts and Exercise

Brought to you by Core Kids, WMUBrought to you by Core Kids, WMU--MGRRE MGRRE Geosciences KGeosciences K--12 Outreach Program12 Outreach ProgramGeosciences KGeosciences K--12 Outreach Program 12 Outreach Program

With generous support from:

In this presentation and dataIn this presentation and data--based based exercise students will:exercise students will:

Learn about a critical natural resourceLearn about a critical natural resource -- waterwaterLearn about a critical natural resource Learn about a critical natural resource waterwaterLearn about the science used by the professionals Learn about the science used by the professionals who manage our water resourceswho manage our water resourceswho manage our water resources.who manage our water resources.Learn about the subsurface geology of Michigan Learn about the subsurface geology of Michigan

d h f h i l ld h f h i l land that of their localeand that of their localeLearn to access public databases on natural Learn to access public databases on natural resources compiled by the State of Michiganresources compiled by the State of Michigan

Hydrogeology ConceptsHydrogeology ConceptsHydrogeology ConceptsHydrogeology Concepts

The water cycle The water cycle or hydrologic or hydrologic y gy gcycle shows the cycle shows the continuous continuous movement of movement of water on, above, water on, above,

d b l thd b l thand below the and below the Earth’s surface.Earth’s surface.

Hydrogeology ConceptsHydrogeology Concepts

Hydrology is the scientific study of theHydrology is the scientific study of the


Hydrology is the scientific study of the Hydrology is the scientific study of the properties, distribution, and effects of water on properties, distribution, and effects of water on the earth's surface, in the soil and underlying the earth's surface, in the soil and underlying y gy grocks, and in the atmosphere.rocks, and in the atmosphere.Hydrogeologists study the distribution and Hydrogeologists study the distribution and y g g yy g g ymovement of water movement of water belowbelow the Earth's surface, the Earth's surface, especially the distribution of groundwater, it’s especially the distribution of groundwater, it’s fl d d lifl d d liflow, and groundwater quality.flow, and groundwater quality.

Hydrogeologists & Hydrogeologists & Hydrologists In ActionHydrologists In ActionHydrologists In ActionHydrologists In Action

Hydrogeology ConceptsHydrogeology ConceptsHydrogeology ConceptsHydrogeology ConceptsHydrogeologists need to understand what is Hydrogeologists need to understand what is under the ground surface in Michigan to know under the ground surface in Michigan to know more about groundwater supplies here.more about groundwater supplies here.Michigan is underlain by thousands of feet of Michigan is underlain by thousands of feet of bedrock, but most drinking water supplies are bedrock, but most drinking water supplies are g ppg ppfound in the uppermost few hundred feet.found in the uppermost few hundred feet.Geologic storage locations holding water areGeologic storage locations holding water areGeologic storage locations holding water are Geologic storage locations holding water are termed aquifers.termed aquifers.

Glaciers Shaped Michigan’s SurfaceGlaciers Shaped Michigan’s Surface

Adapted from Charles Barker, 2005

Layers of Rock of the Grand Canyon

Layers of Rock Under Michigan

Depth in Feet Below the Surfacey g

Grand Canyon Rock Layer Thickness vs.

- 0-1,000- 2 000y

Michigan Bedrock Thicknesses

2,000- 3,000- 4,000- 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 GlaciationThe bedrock of The bedrock of Michigan was deposited Michigan was deposited i b i hi hi b i hi hin a basin which appears in a basin which appears similar to as set of similar to as set of nested bowlsnested bowlsnested bowls.nested bowls.

Adapted from Olcott 1992 andModified from S. E. Wilson, 2006

Adapted from Olcott, 1992, and modified from Robinson, 2004


Hydrogeologists study rocks and their propertiesHydrogeologists study rocks and their properties


Hydrogeologists study rocks and their properties Hydrogeologists study rocks and their properties to understand how water moves underground.to understand how water moves underground.These properties include:These properties include:These properties include:These properties include:

Consolidated vs. unconsolidated aquifer materialConsolidated vs. unconsolidated aquifer materialT d h f h i ki h ifT d h f h i ki h ifType and shape of the grains making up the aquiferType and shape of the grains making up the aquiferHow the material affects water flowHow the material affects water flowPotential environments of depositionPotential environments of deposition

S E l fSome Examples of Unconsolidated Sediments

Medium Sand

Coarse Sand ClayPebbles/Gravel

SiltFine SandVery Fine Sand

When unconsolidated sediments become lithified they are called Consolidated Sediments or Rocks

I i f dInsert images from penn sandstones, etc.

Sandstone Siltstone


Porosity is the amount of space between the grains


Porosity is the amount of space between the grains of sediment in unconsolidated or consolidated aquifer materialsaquifer materials.The amount of “pore space” is determined by the shape size and sorting of the grains and anyshape, size, and sorting of the grains and any cements holding the grains together.Th h h hThe greater the pore space, the more porous the material is.

Sediment Grain Shape Analysis Tool

Grain roundness affects how sediments fit together when

t d lithifi d

From Jones & Jones, 2003

compacted or lithified.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.

L i “fl ” iLarger grains may “float” in a matrix of smaller grains.


When the pores of a material are connected


When the pores of a material are connected together, water and other fluids can flow through the materialthe material.The more fluids that can pass through the pores, the more permeable a material ismore permeable a material is.Rocks are porous, but may not be considered

bl d di h h i i f hpermeable depending upon the characteristics of the pores and how they are connected.

Sediment: Sand Rock: Sandstone


Water stored in the pores of unconsolidated and


Water stored in the pores of unconsolidated and consolidated material is affected by gravity and pressurepressure.The water table level at any location is an example of these effectsof these effects.Pollution is a major threat to the relatively shallow

f h bl d fi d if inature of the water table and unconfined aquifers in many parts of Michigan.

From Jones & Jones 2002From Jones & Jones, 2002

Hydrogeologic Vocabulary:Zone of aeration is where pores are filled mostly with airZone 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 zonesWater table is the boundary between the two zones.


In Michigan, aquifers in unconsolidated, glacial


In Michigan, aquifers in unconsolidated, glacial sediments are termed unconfined aquifers.

Easier to access, shallower,More prone to pollution

Bedrock aquifers are usually confined, or q y ,bounded by other rock units that do not allow as much or any water to pass.

May be harder to access, but less easily pollutedIf too deep may be briny

Glacial Sediments and Bedrock AquifersGlacial 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

Hydrogeologic Vocabulary:

Unconfined AquiferConfined Aquifer

Pumping wells affect the water in the pores of the aquifer surrounding them forming a cone of depression. I fi d di i f h iIn confined conditions, water pressure from recharge in higher elevation areas can force wells to flow aboveground in lower-lying areas. y gThese are called artesian wells or springs.

Hydrogeology ConceptsHydrogeology ConceptsHydrogeology ConceptsHydrogeology 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 quality, quantity, and availability.q y, q y, y

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 andThe sandstones may be

good water-bearing source k

Lithification turns sands to sandstone, and muds to mudstone and siltstone.

rocks.The mudstones and

siltstones may be barrierssiltstones may be barriers to water flow.

Organic material trapped i h k fin the rocks from swampy areas may cause poor water quality from the q yrelease 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 h d b d k f b l koccur in areas where deep bedrock aquifers are briny, like in

Michigan’s rock formations deposited from seas.

Exercise:Exercise:Water Wells & LithologyWater Wells & Lithology

Brought to you by Core Kids, WMUBrought to you by Core Kids, WMU--MGRRE Geosciences KMGRRE Geosciences K--12 Outreach 12 Outreach

PPProgram Program

Exercise created by Niah Venable, Amanda Walega and Exercise created by Niah Venable, Amanda Walega and S G ith b t t b Ni h V blS G ith b t t b Ni h V blSusan Grammer with web content by Niah VenableSusan Grammer with web content by Niah Venable

A special thanks toA special thanks to88thth grade teacher Becky Dalecki, Portage North Middle School and to thegrade teacher Becky Dalecki, Portage North Middle School and to the

88thth d i t h d t d t t M tt Middl S h ld i t h d t d t t M tt Middl S h l88thth grade science teachers and students at Mattawan Middle School.grade science teachers and students at Mattawan Middle School.

With generous support from:

This exercise can be adapted for:This exercise can be adapted for:This exercise can be adapted for:This exercise can be adapted for:

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

Exercise StepsExercise Steps

1. Choose an area of interest (e.g. Charlotte, MI)1. Choose an area of interest (e.g. Charlotte, MI)

Exercise StepsExercise Steps

1. Choose an area of interest (e.g. Charlotte, MI)1. Choose an area of interest (e.g. Charlotte, MI)2. Find the corresponding topographic map2. Find the corresponding topographic map3 Find water well data from the area of interest3 Find water well data from the area of interest3. Find water well data from the area of interest3. Find water well data from the area of interest4. Interpret water well driller’s logs4. Interpret water well driller’s logs5 C li h l i l5 C li h l i l5. Create lithologic columns5. Create lithologic columns6. Calculate the Well Elevation6. Calculate the Well Elevation7. Create stratigraphic columns7. Create stratigraphic columns8. Create cross8. Create cross--sections for comparisonsections for comparison

1. Pick an Area of Interest1. Pick an Area of Interest1. Pick an Area of Interest1. Pick an Area of Interest

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

2. Find a Topo Map2. Find a Topo Map2. Find a Topo Map2. Find a Topo MapBrowse to the State of Michigan, Browse to the State of Michigan, Department of Natural ResourcesDepartment of Natural ResourcesDepartment of Natural Resources Department of Natural Resources homepage: homepage: www.michigan.gov/dnrwww.michigan.gov/dnrFrom there browse to PublicationsFrom there browse to PublicationsFrom there browse to Publications From there browse to Publications and Maps, then Online Maps. Go and Maps, then Online Maps. Go to Topographic Quadrangles by to Topographic Quadrangles by Location.Location.Location.Location.Use the dropdown list to find the Use the dropdown list to find the county, in this case it is Eaton. A county, in this case it is Eaton. A quick link to this page is:quick link to this page is:quick link to this page is: 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.htmlClick Download. Click Download. c w d.c w d.

2. Find a Topo Map cont.2. Find a Topo Map cont.2. Find a Topo Map cont.2. Find a Topo Map cont.

The ne t screen sho s aThe ne t screen sho s aThe next screen shows a The next screen shows a green and yellow version of a green and yellow version of a political map with the political map with the locations of cities and towns locations of cities and towns with a blue grid overlay of with a blue grid overlay of the quadrangle names. the quadrangle names. q gq gClick on the quad labeled Click on the quad labeled “Charlotte” in Eaton and “Charlotte” in Eaton and C l hiC l hiCarmel townships.Carmel townships.

2. Find a Topo Map cont.2. Find a Topo Map cont.

A pdf of the A pdf of the

2. Find a Topo Map cont.2. Find a Topo Map cont.

ppCharlotte quadrangle Charlotte quadrangle will open in Adobe will open in Adobe Acrobat We canAcrobat We canAcrobat. We can Acrobat. We can save this and use assave this and use as--is is or copy and zoom to or copy and zoom to a portion of the map a portion of the map using MS Word or using MS Word or image handling image handling g gg gsoftware.software.

3. Find Water Well Data3. Find Water Well Data3. Find Water Well Data3. Find Water Well Data

Browse to the State of Browse to the State of Michigan, Department of Michigan, Department of Environmental Quality Environmental Quality homepage: homepage:

i hi /di hi /dwww.michigan.gov/deqwww.michigan.gov/deqFrom there click Water, then From there click Water, then browse to Drinking Water, to browse to Drinking Water, to W t W ll C t ti thW t W ll C t ti thWater Well Construction, then Water Well Construction, then click on Scanned Water Well click on Scanned Water Well Record Retrieval System.Record Retrieval System.A i k li k t thi iA i k li k t thi iA quick link to this page is: A quick link to this page is: www.deq.state.mi.us/wellwww.deq.state.mi.us/well--logs/logs/

3. Find Water Well Data cont.3. Find Water Well Data cont.3. Find Water Well Data cont.3. Find Water Well Data cont.The information used to find The information used to find the topo and the map itselfthe topo and the map itselfthe topo and the map itself the topo and the map itself provide the county, township provide the county, township and section data we need to and section data we need to search the well retrievalsearch the well retrievalsearch the well retrieval search the well retrieval database.database.We are interested in Eaton We are interested in Eaton C nt t r h n dC nt t r h n dCounty so two searches need County so two searches need to be done by township, one to be done by township, one for Eaton in sections 6, 18 for Eaton in sections 6, 18

d 19 d f C ld 19 d f C land 19; and one for Carmel and 19; and one for Carmel in sections 12, 13, and 24. in sections 12, 13, and 24. We will omit section 7 of We will omit section 7 of E t t hi d tE t t hi d tEaton township, due to an Eaton township, due to an absence of usable logs.absence of usable logs.

3. Find Water Well Data cont.3. Find Water Well Data cont.

After selecting the county, After selecting the county,

3. Find Water Well Data cont.3. Find Water Well Data cont.

g y,g y,township(s) and section(s) township(s) and section(s) of interest, we will be able of interest, we will be able to review a pdf file to review a pdf file containing the scanned containing the scanned images of driller’s reportsimages of driller’s reportsimages of driller s reports images of driller s reports from each area. from each area. The pdf driller’s reports orThe pdf driller’s reports orThe pdf driller s reports or The pdf driller s reports or logs will look like this. The logs will look like this. The number of logs available number of logs available ggfor each section varies.for each section varies.

4. Interpreting Driller’s Logs4. Interpreting Driller’s Logs4. Interpreting Driller s Logs4. Interpreting Driller s Logs

The driller’s log headerThe driller’s log headerThe driller s log header The driller s log header contains well location contains well location information and often a information and often a handhand--drawn map with drawn map with street names, which may street names, which may

f l if hf l if hprove useful if the prove useful if the quarterquarter--quarter location quarter location information is notinformation is notinformation is not information is not recorded, or recorded recorded, or recorded incorrectly.incorrectly.yy

4. Interpreting Driller’s Logs cont.4. Interpreting Driller’s Logs cont.4. Interpreting Driller s Logs cont.4. Interpreting Driller s Logs cont.The driller’s log lithology The driller’s log lithology information is listed byinformation is listed byinformation is listed by information is listed by type of material, type of material, thickness of each unit,thickness of each unit,thickness of each unit, thickness of each unit, and total depth. The and total depth. The formation descriptions formation descriptions are more likely to be are more likely to be generic than scientific. generic than scientific. The total drilled depth of The total drilled depth of this well is 100 feet this well is 100 feet b l th rfb l th rfbelow the surface.below the surface.

4. Interpreting Driller’s Logs cont.4. Interpreting Driller’s Logs cont.Other information Other information provided by the driller’sprovided by the driller’s

4. Interpreting Driller s Logs cont.4. Interpreting Driller s Logs cont.

provided by the driller s provided by the driller s log is the owner of the log is the owner of the well, the depth, the well, the depth, the completion date and how completion date and how ppthe well was completed. the well was completed. It will also list possible It will also list possible sources of contaminationsources of contaminationsources of contamination, sources of contamination, pump type, and who pump type, and who drilled the well. drilled the well. The static water level isThe static water level isThe static water level is The static water level is equal to the depth to the equal to the depth to the water table, in this case it water table, in this case it was encountered 36 feetwas encountered 36 feetwas encountered 36 feet was encountered 36 feet below the surface.below the surface.

5. Creating Lithologic Columns5. Creating Lithologic Columns

Li h l i i hiLi h l i i hi

5. Creating Lithologic Columns5. Creating Lithologic Columns

Lithologic or stratigraphic Lithologic or stratigraphic columns can be created columns can be created from driller’s logs using from driller’s logs using g gg gthe formation descriptions the formation descriptions provided by the driller and provided by the driller and th d th t d thth d th t d th

From 0From 0--12 feet below the surface the 12 feet below the surface the driller encountered clay.driller encountered clay.F 12 16 f b l h fF 12 16 f b l h fthe depths to and the the depths to and the

thicknesses of each unit.thicknesses of each unit.From 12 to 16 feet below the surface From 12 to 16 feet below the surface they found sand.they found sand.From 16 to 54 feet below the surface From 16 to 54 feet below the surface h f d lh f d lthey found clay.they found clay.

From 54 to 60 feet below was gravel.From 54 to 60 feet below was gravel.From 60 to 100 feet below the surface From 60 to 100 feet below the surface they found “sandrock”, most likely the they found “sandrock”, most likely the sandstones of the Saginaw Aquifer.sandstones of the Saginaw Aquifer.

5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.

A basic form created in A basic form created in Excel is useful for Excel is useful for plotting lithogy and other plotting lithogy and other

ll i f rm ti f rll i f rm ti f rwell information for well information for viewing as a lithologic or viewing as a lithologic or stratigraphic column.stratigraphic column.g pg pThe lithologic key can be The lithologic key can be modified depending on modified depending on h f h i lh f h i lthe type of earth material the type of earth material

encountered in the wells.encountered in the wells.

5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.5. Creating Lithologic Columns cont.

Using the driller’s log Using the driller’s log Hammond g gg gdepths below the surface depths below the surface as a guide, we plot the as a guide, we plot the lith l i t p thlith l i t p thlithologic types on the lithologic types on the column with the column with the lithologic key patterns lithologic key patterns g y pg y pand colors as fill.and colors as fill.Next, we mark the water Next, we mark the water l l h ll l h llevel on the column level on the column using the symbol from using the symbol from the key.the key.yy

6. Calculate the Well Elevation6. Calculate the Well Elevation

To calculate the well elevationTo calculate the well elevation

6. Calculate the Well Elevation6. Calculate the Well Elevation

To calculate the well elevation To calculate the well elevation values in feet above sea level and values in feet above sea level and to convert the lithogic column to to convert the lithogic column to a stratigraphic column, we must a stratigraphic column, we must first determine the well surface first determine the well surface l il ielevation.elevation.

This is done using a topographic This is done using a topographic p i t f th drill r’p i t f th drill r’map since most of the driller’s map since most of the driller’s

reports do not provide well reports do not provide well elevations.elevations.elevations.elevations.

6. Calculate the Well Elevation cont.6. Calculate the Well Elevation cont.

Using the topo map of Charlotte Using the topo map of Charlotte g p pg p pand the location information and the location information provided in the driller’s report provided in the driller’s report

fi d th t th mpl ll ifi d th t th mpl ll iwe find that the example well is we find that the example well is located here.located here.Contour lines in this area rangeContour lines in this area rangeContour lines in this area range Contour lines in this area range between 910 feet and 920 feet between 910 feet and 920 feet above sea level. Interpolating above sea level. Interpolating h l i b hh l i b hthe location between the two the location between the two

contours gives us a value of 918 contours gives us a value of 918 feet above sea level.feet above sea level.

6. Calculate the Well Elevation cont.6. Calculate the Well Elevation cont.6. Calculate the Well Elevation cont.6. Calculate the Well Elevation cont.

We record the well We record the well elevation in the blank to the elevation in the blank to the right. And then place the right. And then place the

l th t li f thl th t li f thvalue on the top line of the value on the top line of the scale on the right side of the scale on the right side of the lithology columnlithology columnlithology column.lithology column.Next we subtract the depths Next we subtract the depths in ten foot increments from in ten foot increments from te oot c e e ts ote oot c e e ts othe elevation value until the the elevation value until the bottom of the well is bottom of the well is reached.reached.

7. Create Multiple Strat Columns7. Create Multiple Strat Columns7. Create Multiple Strat Columns7. Create Multiple Strat Columns

To compare the hydrogeology from several wellsTo compare the hydrogeology from several wellsTo compare the hydrogeology from several wells To compare the hydrogeology from several wells around the Charlotte area we must create more around the Charlotte area we must create more stratigraphic columns.stratigraphic columns.g pg pRepeat steps 3 through 6 to create these columns.Repeat steps 3 through 6 to create these columns.For this example we will use driller’s logs fromFor this example we will use driller’s logs fromFor this example we will use driller s logs from For this example we will use driller s logs from Eaton township, sections 18 and 19, and Carmel Eaton township, sections 18 and 19, and Carmel township sections 12 13 and 24.township sections 12 13 and 24.township, sections 12, 13, and 24.township, sections 12, 13, and 24.We will mark the locations of all the wells on the We will mark the locations of all the wells on the topo map for referencetopo map for referencetopo map for reference.topo map for reference.

7. Multiple Strat Columns cont.7. Multiple Strat Columns cont.pp

Hammond

All of the wells are now marked All of the wells are now marked on the topographic map for on the topographic map for o opog p c p oo opog p c p oreference.reference.Well elevation values have been Well elevation values have been

Mishler

picked from the map and used to picked from the map and used to convert the lithologic columns to convert the lithologic columns to

Burt

Porter

stratigraphic columns.stratigraphic columns.

Archer

City

Archer

7. Multiple Strat Columns cont.7. Multiple Strat Columns cont.7. Multiple Strat Columns cont.7. Multiple Strat Columns cont.

Once the stratigraphicOnce the stratigraphicWell Name and Elevation Range:Well Name and Elevation Range:

Once the stratigraphic Once the stratigraphic columns are created, a columns are created, a depth datum is picked.depth datum is picked.

Hammond: 918Hammond: 918--818 ft.818 ft.Burt: 890Burt: 890--790 ft.790 ft.City: 912City: 912--872 ft872 ftp pp p

The depth datum is used The depth datum is used to compare the lithology to compare the lithology

City: 912City: 912--872 ft.872 ft.Archer: 895Archer: 895--775 ft.775 ft.Porter: 900Porter: 900--800 ft.800 ft.p gyp gy

and water levels in all and water levels in all wells at corresponding wells at corresponding d hd h

Mischler: 945Mischler: 945--835 ft.835 ft.

The depth datum should be The depth datum should be 880 f t b l l i880 f t b l l idepths. depths. 880 feet above sea level since 880 feet above sea level since all wells intersect that depth.all wells intersect that depth.

8. Cross8. Cross--Section CreationSection Creation

The geographic area The geographic area covered by the wellscovered by the wells

Bcovered by the wells covered by the wells can be divided into two can be divided into two crosscross--sectional linessectional lines Acrosscross sectional lines sectional lines running approximately running approximately North to SouthNorth to South

A

They are labeled A to They are labeled A to A’ and B to B’.A’ and B to B’.

A’

B’

8. Cross8. Cross––Section Creation cont.Section Creation cont.8. Cross8. Cross Section Creation cont.Section Creation cont.The wells in each crossThe wells in each cross--section can be compared by section can be compared by lining them up on the datum valuelining them up on the datum valuelining them up on the datum value. lining them up on the datum value.

880 ft880 ft.A A’

~ 1.5 mi.

~ 1 mi.

8. Cross8. Cross––Section Creation cont.Section Creation cont.8. Cross8. Cross Section Creation cont.Section Creation cont.It is important to remember the distances between It is important to remember the distances between wells when making crosswells when making cross--sectional comparisonssectional comparisonswells when making crosswells when making cross sectional comparisons. sectional comparisons.

880 ft.B B’B B

~ 1.75 mi. ~ 2 mi.

9. Interpretation9. Interpretation9. Interpretation9. InterpretationThe crossThe cross--sections combined with the well sections combined with the well l i h i i ll i h i i llocations on the topo map give a spatial locations on the topo map give a spatial comparison of the earth materials encountered comparison of the earth materials encountered

d h d h h i ld h d h h i lat depth and how those materials vary over a at depth and how those materials vary over a distance between wells.distance between wells.The wells are about 1 to 2 miles apart and the The wells are about 1 to 2 miles apart and the relief between the highest and lowest wells is 55 relief between the highest and lowest wells is 55 feet. Static water levels range between a max feet. Static water levels range between a max elevation just under 900 ft. to just over 875 ft. elevation just under 900 ft. to just over 875 ft.

9. Interpretation cont.9. Interpretation cont.9. Interpretation cont.9. Interpretation cont.

The glacial sediments found above theThe glacial sediments found above theThe glacial sediments found above the The glacial sediments found above the sandstone and shale bedrock in this area show sandstone and shale bedrock in this area show variation in type and thickness from well to well, variation in type and thickness from well to well, yp w w ,yp w w ,which is typical of these kinds of materials.which is typical of these kinds of materials.Generally though, the glacial deposits in the AGenerally though, the glacial deposits in the A--y g , g py g , g pA’ wells consist of clay and gravels, while the A’ wells consist of clay and gravels, while the deposits in the Bdeposits in the B--B’ wells are mainly sand and B’ wells are mainly sand and clay.clay.

9. Interpretation cont.9. Interpretation cont.9. Interpretation cont.9. Interpretation cont.

The Charlotte wells show no significant The Charlotte wells show no significant variation in static water levels. Dramatic variation in static water levels. Dramatic variations in static water levels could be due variations in static water levels could be due to draw down effects in heavyto draw down effects in heavy--use areas. use areas. The sandstone and shale bedrock elevations varyThe sandstone and shale bedrock elevations varyThe sandstone and shale bedrock elevations vary The sandstone and shale bedrock elevations vary by 60 ft for all wells, but for each cross section, by 60 ft for all wells, but for each cross section, the variation is between 25the variation is between 25--45 feet45 feetthe variation is between 25the variation is between 25 45 feet.45 feet.

10. Summary10. Summary10. Summary10. SummaryTopographic maps and water well driller’s Topographic maps and water well driller’s l b d i hl b d i h fflogs can be used to examine the nearlogs can be used to examine the near--surface surface geology of Michigan. geology of Michigan. The driller’s logs are also useful for determining The driller’s logs are also useful for determining depth to the water table, potential nearby depth to the water table, potential nearby

i i h d d h i f ii i h d d h i f icontamination hazards, and other information.contamination hazards, and other information.The data needed for these exercises is readily The data needed for these exercises is readily

il bl h i f S f Mi hiil bl h i f S f Mi hiavailable on the internet from State of Michigan available on the internet from State of Michigan sources. sources.

hydrogeology cdiconcepts and exercise concepts and...hydrogeology concepts hydrology is the...

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