U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3423

Sheet 2 of 2

Pamphlet accompanies map

Figure 5. Interpolated maps of the study area. A, approximate elevation of glacial till surface; B, approximate elevation of the bedrock surface; C, approximate alluvial deposit thickness; D, approximate depth to bedrock surface; and E, three-dimensional fence diagram of the delineated lithologic framework of the study area.

Hiawatha

Robins

91°48' 91°46' 91°44' 91°42'

42°40'

42°20'

42°00'

EXPLANATION

Airborne electromagnetic study area

0 0.5

0.5

1 MILE

0 1 2 KILOMETERS

Cedar River

Cedar River

Cedar Rapids

BLAIRS FERRY ROAD

BLAIRS FERRY ROAD

Covington

¬«94

¬«94

Palo

Map image is the intellectual property of Esri and is used herein under license. 

Copyright © 2018 Esri and its licensors. All rights reserved.

Universal Transverse Mercator, zone 15

North American Datum 1983

IOWA

I-380

Wooded marsh 

Woodland 

Natural area/park

Urban area

A. Approximate elevation of glacial till surface, in meters above the Geodetic Reference System 1980

91°48' 91°46' 91°44'

42°04'

42°02'

42°00'

0 0.5 MILE

Base from U.S. Geological Survey digital data, 2018 0 0.5 1 KILOMETER

Universal Transverse Mercator, zone 15

North American Datum 1983

Low-confidence area

Glacial till surface elevation, in meters above 

Geodetic Reference System 1980

169.3 to 182.9

183.0 to 196.6

196.7 to 210.3

210.4 to 224.0

224.1 to 237.7

237.8 to 251.4

251.5 to 265.1

265.2 to 278.7

EXPLANATION

91°48' 91°46' 91°44'

42°04'

42°02'

42°00'

0 0.5 MILE

Base from U.S. Geological Survey digital data, 2018 0 0.5 1 KILOMETER

Universal Transverse Mercator, zone 15

North American Datum 1983

EXPLANATION

Low-confidence area

Bedrock surface elevation, in meters above 

Geodetic Reference System 1980

168.9 to 179.8

179.9 to 190.6

190.7 to 201.5

201.6 to 212.4

212.5 to 223.2

223.3 to 234.1

234.2 to 245.0

245.1 to 255.8

B. Approximate elevation of the bedrock surface, in meters above the Geodetic Reference System 1980

91°48' 91°46' 91°44'

42°04'

42°02'

42°00'

0 0.5 MILE

Base from U.S. Geological Survey digital data, 2018 0 0.5 1 KILOMETER

Universal Transverse Mercator, zone 15

North American Datum 1983

EXPLANATION

Low-confidence area

Alluvial deposit thickness, in meters

0 to 1.0

1.1 to 6.0

6.1 to 12.0

12.1 to 18.0

18.1 to 24.0

24.1 to 30.0

30.1 to 36.0

36.1 to 42.0

42.1 to 48.0

48.1 to 54.0

C. Approximate alluvial deposit thickness, in meters

91°48' 91°46' 91°44'

42°04'

42°02'

42°00'

0 0.5 MILE

0 0.5 1 KILOMETER Base from U.S. Geological Survey digital data, 2018

Universal Transverse Mercator, zone 15

North American Datum 1983

Depth to bedrock, in meters

0 to 1.0

1.1 to 11.0

11.1 to 21.0

21.1 to 31.0

31.1 to 41.0

41.1 to 51.0

51.1 to 61.0

61.1 tov 72.0

D. Approximate depth to bedrock surface, in meters

EXPLANATION

Low-confidence area

150

190

170

210

230

250

Meters

SW

NE

A A'

B B'

C C'

D D'

91°48' 91°46' 91°44' 91°42'

42°04'

42°02'

42°00'

0 1 MILE

0 1 2 KILOMETERS Cedar River

Cedar River

Cedar Rapids

BLAIRS FERRY ROAD

BLAIRS FERRY ROAD

Covington

¬«94

¬«94

Palo

Map image is the intellectual property of Esri and is used herein under license.

Copyright © 2018 Esri and its licensors. All rights reserved.

Universal Transverse Mercator, zone 15

North American Datum 1983

 I–380

0 1 2 KILOMETERS

0 0.5 1 MILE

Alluvial deposit

Glacial till

Bedrock

EXPLANATION

EXPLANATION

Resistivity section (sheet 1)

Fence diagram section

Study area

A A’

Wooded marsh 

Woodland 

Natural area/park

Urban area

E. Three-dimensional fence diagram of the delineated lithologic framework of the study area, in meters

Delineation of Selected Lithologic Units Using Airborne Electromagnetic Data near Cedar Rapids, Iowa

By

Joshua F. Valder, Adel E. Haj, Emilia L. Bristow, and Kristen J. Valseth

2018

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Suggested citation:

Valder, J.F., Haj, A.E., Bristow, E.L., and Valseth, K.J., 2018, Delineation of selected lithologic units using airborne 

electromagnetic data near Cedar Rapids, Iowa: U.S. Geological Survey Scientific Investigations Map 3423, 2 sheets, 

9-p. pamphlet, https://doi.org/10.3133/sim3423.

This map is offered as an online-only, digital publication. Users should be aware that, because of differences in 

rendering processes and pixel resolution, some slight distortion of scale may occur when viewing it on a computer 

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ISSN 2329-132X (online)