Geochemical and Mineralogical Maps for Soils of the 

Conterminous United States

Open-File Report 2014–1082

U.S. Department of the Interior

U.S. Geological Survey
Geochemical and Mineralogical Maps for Soils of the 

Conterminous United States

By David B. Smith, William F. Cannon, Laurel G. Woodruff, Federico Solano, and Karl J. Ellefsen

Open-File Report 2014–1082

U.S. Department of the Interior

U.S. Geological Survey
ii

U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2014

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Suggested citation:

Smith, D.B., Cannon, W.F., Woodruff, L.G., Solano, Federico, and Ellefsen, K.J., 2014, Geochemical and 

mineralogical maps for soils of the conterminous United States: U.S. Geological Survey Open-File Report 

2014–1082, 386 p., http://dx.doi.org/10.3133/ofr20141082.

ISSN 2331-1258 (online)

Any use of trade, firm, or product names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this information product, for the most part, is in the public domain, it also may contain

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secured from the copyright owner.
iii

Contents

Abstract .....................................................................................................................................................................1

Introduction................................................................................................................................................................1

Sampling....................................................................................................................................................................4

Chemical Analysis .....................................................................................................................................................4

Mineralogical Analysis ...............................................................................................................................................5

Map Generation.........................................................................................................................................................5

Interpolated Surface Maps .....................................................................................................................................5

Proportional Symbol Maps .....................................................................................................................................6

Explanation of Figures ...............................................................................................................................................7

References Cited.......................................................................................................................................................7

Figures

Figure 1. Map showing the location of 4,857 soil sampling sites in the conterminous United States ....................3

Figure 2. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of aluminum (Al) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................12

Figure 3. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of aluminum (Al) in the soil A horizon, conterminous United States ..........................................14

Figure 4. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of aluminum (Al) in the soil C horizon, conterminous United States ..........................................16

Figure 5. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of antimony (Sb) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................18

Figure 6. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of antimony (Sb) in the soil A horizon, conterminous United States ..........................................19

Figure 7. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of antimony (Sb) in the soil C horizon, conterminous United States..........................................22

Figure 8. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of arsenic (As) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................24

Figure 9. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of arsenic (As) in the soil A horizon, conterminous United States .............................................26

Figure 10. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of arsenic (As) in the soil C horizon, conterminous United States .............................................28

Figure 11. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of barium (Ba) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................29

Figure 12. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of barium (Ba) in the soil A horizon, conterminous United States..............................................32

Figure 13. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of barium (Ba) in the soil C horizon, conterminous United States..............................................34
iv

Figure 14. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of beryllium (Be) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................36

Figure 15. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of beryllium (Be) in the soil A horizon, conterminous United States ..........................................38

Figure 16. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of beryllium (Be) in the soil C horizon, conterminous United States ..........................................39

Figure 17. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of bismuth (Bi) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................42

Figure 18. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of bismuth (Bi) in the soil A horizon, conterminous United States .............................................44

Figure 19. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of bismuth (Bi) in the soil C horizon, conterminous United States .............................................46

Figure 20. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cadmium (Cd) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................48

Figure 21. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cadmium (Cd) in the soil A horizon, conterminous United States..........................................49

Figure 22. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cadmium (Cd) in the soil C horizon, conterminous United States..........................................52

Figure 23. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of calcium (Ca) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................54

Figure 24. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of calcium (Ca) in the soil A horizon, conterminous United States ............................................56

Figure 25. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of calcium (Ca) in the soil C horizon, conterminous United States ............................................58

Figure 26. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total carbon (C) in the soil A horizon, conterminous United States........................................59

Figure 27. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total carbon (C) in the soil C horizon, conterminous United States........................................62

Figure 28. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of inorganic carbon (C) in the soil A horizon, conterminous United States................................63

Figure 29. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of inorganic carbon (C) in the soil C horizon, conterminous United States................................65

Figure 30. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of organic carbon (C) in the soil A horizon, conterminous United States...................................67

Figure 31. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of organic carbon (C) in the soil C horizon, conterminous United States...................................69

Figure 32. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cerium (Ce) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................71

Figure 33. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cerium (Ce) in the soil A horizon, conterminous United States..............................................73

Figure 34. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cerium (Ce) in the soil C horizon, conterminous United States..............................................75
v

Figure 35. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cesium (Cs) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................77

Figure 36. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cesium (Cs) in the soil A horizon, conterminous United States .............................................79

Figure 37. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cesium (Cs) in the soil C horizon, conterminous United States .............................................81

Figure 38. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of chromium (Cr) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................83

Figure 39. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of chromium (Cr) in the soil A horizon, conterminous United States..........................................85

Figure 40. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of chromium (Cr) in the soil C horizon, conterminous United States .........................................87

Figure 41. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cobalt (Co) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................89

Figure 42. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cobalt (Co) in the soil A horizon, conterminous United States...............................................91

Figure 43. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of cobalt (Co) in the soil C horizon, conterminous United States...............................................93

Figure 44. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of copper (Cu) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States.....................................................................................................................................95

Figure 45. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of copper (Cu) in the soil A horizon, conterminous United States .............................................97

Figure 46. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of copper (Cu) in the soil C horizon, conterminous United States .............................................99

Figure 47. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gallium (Ga) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................101

Figure 48. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gallium (Ga) in the soil A horizon, conterminous United States...........................................104

Figure 49. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gallium (Ga) in the soil C horizon, conterminous United States...........................................105

Figure 50. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of indium (In) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................107

Figure 51. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of indium (In) in the soil A horizon, conterminous United States .............................................109

Figure 52. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of indium (In) in the soil C horizon, conterminous United States .............................................111

Figure 53. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of iron (Fe) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................113

Figure 54. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of iron (Fe) in the soil A horizon, conterminous United States.................................................115
vi

Figure 55. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of iron (Fe) in the soil C horizon, conterminous United States.................................................117

Figure 56. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lanthanum (La) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................119

Figure 57. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lanthanum (La) in the soil A horizon, conterminous United States ......................................121

Figure 58. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lanthanum (La) in the soil C horizon, conterminous United States ......................................123

Figure 59. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lead (Pb) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................125

Figure 60. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lead (Pb) in the soil A horizon, conterminous United States................................................128

Figure 61. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lead (Pb) in the soil C horizon, conterminous United States................................................129

Figure 62. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lithium (Li) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................131

Figure 63. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lithium (Li) in the soil A horizon, conterminous United States..............................................133

Figure 64. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of lithium (Li) in the soil C horizon, conterminous United States..............................................135

Figure 65. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of magnesium (Mg) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................137

Figure 66. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of magnesium (Mg) in the soil A horizon, conterminous United States....................................139

Figure 67. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of magnesium (Mg) in the soil C horizon, conterminous United States ...................................141

Figure 68. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of manganese (Mn) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................143

Figure 69. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of manganese (Mn) in the soil A horizon, conterminous United States ...................................145

Figure 70. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of manganese (Mn) in the soil C horizon, conterminous United States ...................................148

Figure 71. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of mercury (Hg) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................149

Figure 72. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of mercury (Hg) in the soil A horizon, conterminous United States..........................................151

Figure 73. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of mercury (Hg) in the soil C horizon, conterminous United States .........................................153

Figure 74. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of molybdenum (Mo) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................155
vii

Figure 75. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of molybdenum (Mo) in the soil A horizon, conterminous United States..................................157

Figure 76. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of molybdenum (Mo) in the soil C horizon, conterminous United States .................................159

Figure 77. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of nickel (Ni) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................161

Figure 78. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of nickel (Ni) in the soil A horizon, conterminous United States ..............................................163

Figure 79. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of nickel (Ni) in the soil C horizon, conterminous United States ..............................................165

Figure 80. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of niobium (Nb) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................167

Figure 81. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of niobium (Nb) in the soil A horizon, conterminous United States..........................................169

Figure 82. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of niobium (Nb) in the soil C horizon, conterminous United States..........................................171

Figure 83. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of phosphorus (P) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................173

Figure 84. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of phosphorus (P) in the soil A horizon, conterminous United States......................................175

Figure 85. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of phosphorus (P) in the soil C horizon, conterminous United States......................................177

Figure 86. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of potassium (K) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................179

Figure 87. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of potassium (K) in the soil A horizon, conterminous United States ........................................181

Figure 88. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of potassium (K) in the soil C horizon, conterminous United States ........................................183

Figure 89. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of rubidium (Rb) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................185

Figure 90. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of rubidium (Rb) in the soil A horizon, conterminous United States.........................................187

Figure 91. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of rubidium (Rb) in the soil C horizon, conterminous United States.........................................189

Figure 92. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of scandium (Sc) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................191

Figure 93. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of scandium (Sc) in the soil A horizon, conterminous United States........................................193

Figure 94. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of scandium (Sc) in the soil C horizon, conterminous United States .......................................195
viii

Figure 95. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of selenium (Se) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................197

Figure 96. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of selenium (Se) in the soil A horizon, conterminous United States ........................................199

Figure 97. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of selenium (Se) in the soil C horizon, conterminous United States ........................................201

Figure 98. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of silver (Ag) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................203

Figure 99. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of silver (Ag) in the soil A horizon, conterminous United States ..............................................205

Figure 100. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of silver (Ag) in the soil C horizon, conterminous United States ..............................................207

Figure 101. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sodium (Na) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................209

Figure 102. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sodium (Na) in the soil A horizon, conterminous United States...........................................211

Figure 103. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sodium (Na) in the soil C horizon, conterminous United States...........................................213

Figure 104. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of strontium (Sr) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................215

Figure 105. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of strontium (Sr) in the soil A horizon, conterminous United States.........................................217

Figure 106. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of strontium (Sr) in the soil C horizon, conterminous United States.........................................219

Figure 107. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sulfur (S) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................221

Figure 108. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sulfur (S) in the soil A horizon, conterminous United States................................................223

Figure 109. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of sulfur (S) in the soil C horizon, conterminous United States................................................225

Figure 110. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tellurium (Te) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................227

Figure 111. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tellurium (Te) in the soil A horizon, conterminous United States .........................................229

Figure 112. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tellurium (Te) in the soil C horizon, conterminous United States .........................................231

Figure 113. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thallium (Tl) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................233

Figure 114. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thallium (Tl) in the soil A horizon, conterminous United States............................................235
ix

Figure 115. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thallium (Tl) in the soil C horizon, conterminous United States ...........................................237

Figure 116. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thorium (Th) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................239

Figure 117. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thorium (Th) in the soil A horizon, conterminous United States...........................................241

Figure 118. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of thorium (Th) in the soil C horizon, conterminous United States...........................................243

Figure 119. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tin (Sn) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................245

Figure 120. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tin (Sn) in the soil A horizon, conterminous United States...................................................247

Figure 121. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tin (Sn) in the soil C horizon, conterminous United States...................................................249

Figure 122. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of titanium (Ti) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................251

Figure 123. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of titanium (Ti) in the soil A horizon, conterminous United States ...........................................253

Figure 124. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of titanium (Ti) in the soil C horizon, conterminous United States ...........................................255

Figure 125. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tungsten (W) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................257

Figure 126. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tungsten (W) in the soil A horizon, conterminous United States..........................................259

Figure 127. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of tungsten (W) in the soil C horizon, conterminous United States..........................................261

Figure 128. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of uranium (U) in surface soils collected from a depth of 0 to 5 centimeters,

conterminous United States...................................................................................................................................263

Figure 129. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of uranium (U) in the soil A horizon, conterminous United States ...........................................265

Figure 130. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of uranium (U) in the soil C horizon, conterminous United States ...........................................267

Figure 131. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of vanadium (V) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................269

Figure 132. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of vanadium (V) in the soil A horizon, conterminous United States .........................................271

Figure 133. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of vanadium (V) in the soil C horizon, conterminous United States.........................................273

Figure 134. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of yttrium (Y) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................275
x

Figure 135. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of yttrium (Y) in the soil A horizon, conterminous United States..............................................277

Figure 136. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of yttrium (Y) in the soil C horizon, conterminous United States..............................................278

Figure 137. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of zinc (Zn) in surface soils collected from a depth of 0 to 5 centimeters, 

conterminous United States...................................................................................................................................280

Figure 138. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of zinc (Zn) in the soil A horizon, conterminous United States ................................................282

Figure 139. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of zinc (Zn) in the soil C horizon, conterminous United States ................................................284

Figure 140. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of quartz in the soil A horizon, conterminous United States ....................................................286

Figure 141. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of quartz in the soil C horizon, conterminous United States ....................................................288

Figure 142. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total potassium feldspar (K-feldspar) in the soil A horizon, conterminous United States .....290

Figure 143. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total potassium feldspar (K-feldspar) in the soil C horizon, conterminous United States.....292

Figure 144. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total plagioclase in the soil A horizon, conterminous United States.....................................294

Figure 145. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total plagioclase in the soil C horizon, conterminous United States.....................................296

Figure 146. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total feldspar (total potassium feldspar + total plagioclase) in the soil A horizon, 

conterminous United States...................................................................................................................................298

Figure 147. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total feldspar (total potassium feldspar + total plagioclase) in the soil C horizon,

conterminous United States...................................................................................................................................300

Figure 148. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total 14-Å clays in the soil A horizon, conterminous United States......................................302

Figure 149. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total 14-Å clays in the soil C horizon, conterminous United States......................................304

Figure 150. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total 10-Å clays in the soil A horizon, conterminous United States......................................306

Figure 151. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total 10-Å clays in the soil C horizon, conterminous United States......................................308

Figure 152. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of kaolinite in the soil A horizon, conterminous United States .................................................310

Figure 153. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of kaolinite in the soil C horizon, conterminous United States .................................................312

Figure 154. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total clay (total 14-Å clays + total 10-Å clays + kaolinite) in the soil A horizon, 

conterminous United States...................................................................................................................................314

Figure 155. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total clay (total 14-Å clays + total 10-Å clays + kaolinite) in the soil C horizon, 

conterminous United States...................................................................................................................................316
xi

Figure 156. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gibbsite in the soil A horizon, conterminous United States ..................................................318

Figure 157. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gibbsite in the soil C horizon, conterminous United States..................................................320

Figure 158. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function;

and D, Distribution of calcite in the soil A horizon, conterminous United States ....................................................322

Figure 159. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of calcite in the soil C horizon, conterminous United States....................................................324

Figure 160. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of dolomite in the soil A horizon, conterminous United States.................................................328

Figure 161. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of dolomite in the soil C horizon, conterminous United States.................................................330

Figure 162. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of aragonite in the soil A horizon, conterminous United States ...............................................330

Figure 163. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of aragonite in the soil C horizon, conterminous United States ...............................................332

Figure 164. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total carbonate (calcite + dolomite + aragonite) in the soil A horizon, 

conterminous United States...................................................................................................................................334

Figure 165. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total carbonate (calcite + dolomite + aragonite) in the soil C horizon, 

conterminous United States...................................................................................................................................336

Figure 166. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of analcime in the soil A horizon, conterminous United States ................................................338

Figure 167. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of analcime in the soil C horizon, conterminous United States................................................340

Figure 168. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of heulandite in the soil A horizon, conterminous United States..............................................342

Figure 169. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of heulandite in the soil C horizon, conterminous United States..............................................344

Figure 170. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total zeolites (analcime + heulandite) in the soil A horizon, conterminous United States ....346

Figure 171. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of total zeolites (analcime + heulandite) in the soil C horizon, conterminous United States ....348

Figure 172. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gypsum in the soil A horizon, conterminous United States..................................................350

Figure 173. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of gypsum in the soil C horizon, conterminous United States..................................................352

Figure 174. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of talc in the soil A horizon, conterminous United States.........................................................354

Figure 175. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of talc in the soil C horizon, conterminous United States.........................................................356

Figure 176. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of hornblende in the soil A horizon, conterminous United States ............................................358

Figure 177. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of hornblende in the soil C horizon, conterminous United States ............................................360
xii

Figure 178. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of serpentine in the soil A horizon, conterminous United States..............................................362

Figure 179. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of serpentine in the soil C horizon, conterminous United States .............................................366

Figure 180. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of hematite in the soil A horizon, conterminous United States.................................................368

Figure 181. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of hematite in the soil C horizon, conterminous United States ................................................368

Figure 182. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of goethite in the soil A horizon, conterminous United States..................................................370

Figure 183. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of goethite in the soil C horizon, conterminous United States .................................................372

Figure 184. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of pyroxene in the soil A horizon, conterminous United States................................................374

Figure 185. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of pyroxene in the soil C horizon, conterminous United States ...............................................376

Figure 186. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of pyrite in the soil A horizon, conterminous United States......................................................378

Figure 187. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of pyrite in the soil C horizon, conterminous United States .....................................................380

Figure 188. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of amorphous component in the soil A horizon, conterminous United States..........................382

Figure 189. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; 

and D, Distribution of amorphous component in the soil C horizon, conterminous United States..........................384
xiii

Conversion Factors

SI to Inch/Pound

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

millimeter (mm) 0.03937 inch (in.)

angstrom 0.00000000394 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

meter (m) 1.094 yard (yd) 

Area

square kilometer (km2) 247.1 acre

square kilometer (km2) 0.3861 square mile (mi2)

Mass

kilogram (kg) 2.205 pound avoirdupois (lb)

milligram 0.0000353 Ounce, avoirdupois (oz)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32
1

Geochemical and Mineralogical Maps for Soils of the 

Conterminous United States

By David B. Smith, William F. Cannon, Laurel G. Woodruff, Federico Solano, and Karl J. Ellefsen

Abstract

The U.S. Geological Survey began sampling in 2007 for a low-density (1 site per 1,600 square 

kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United 

States as part of the North American Soil Geochemical Landscapes Project. The sampling protocol for 

the national-scale survey included, at each site, a sample from a depth of 0 to 5 centimeters, a composite 

of the soil A horizon, and a deeper sample from the soil C horizon or, if the top of the C horizon was at 

a depth greater than 1 meter, a sample from a depth of approximately 80–100 centimeters. The <2-

millimeter fraction of each sample was analyzed for a suite of 45 major and trace elements by methods 

that yield the total or near-total elemental content. The major mineralogical components in the samples 

from the soil A and C horizons were determined by a quantitative X-ray diffraction method using 

Rietveld refinement. Sampling in the conterminous United States was completed in 2010, with chemical 

and mineralogical analyses completed in May 2013. The resulting data set provides an estimate of the 

abundance and spatial distribution of chemical elements and minerals in soils of the conterminous 

United States and represents a baseline for soil geochemistry and mineralogy against which future 

changes may be recognized and quantified. This report releases geochemical and mineralogical maps 

along with a histogram, boxplot, and empirical cumulative distribution function plot for each element or 

mineral.

Introduction

V.M. Goldschmidt, generally considered to be the father of modern-day geochemistry, stated 

that the primary objectives of geochemistry are to determine quantitatively the chemical composition of 

the Earth and its parts and to discover the laws that control the distribution of the individual elements 

(Goldschmidt, 1937, 1954). Understanding the variability in the natural abundance and spatial 

distribution of chemical elements (geochemical background) in the near-surface environment of the 

Earth is important for such fields as risk-based assessment of contaminated land, environmental 

regulation, human and animal health, agriculture, land-use planning, mineral exploration, and water 

quality. Geochemical mapping, conducted at appropriate scales, is the primary method for establishing 

this variability.

Garrett and others (2008) provide a summary of the evolution of regional geochemical mapping. 

Over the past 25 years, numerous collections of regional-, national-, or international-scale geochemical 

maps, or geochemical atlases, have been published based primarily on soils or stream sediments as the 

sample medium (for example, Webb and others, 1973, 1978; Weaver and others, 1983; Fauth and 

others, 1985; Bølviken and others, 1986; Thalmann and others, 1989; Lahermo and others, 1990, 1996; 

Geological Survey of Japan, 1991; British Geological Survey, 1992, 1993; Koljonen, 1992; McGrath 

and Loveland, 1992; Lalor and others, 1995; Lis and Pasieczna, 1995; Reimann and others, 1998, 2003; 
2

Čurlík and Šefčík, 1999; Kadūnas and others, 1999; Li and Wu, 1999; Ottesen and others, 2000; 

Gustavsson and others, 2001; De Vivo and others, 2003; Salminen and others, 2004, 2005; De Vos and 

others, 2006; Xi, 2010, 2011; Caritat and Cooper, 2011; Cohen and others, 2011; Rawlins and others, 

2012; Mol and others, 2012; and Xie and others, 2012). These publications portray elemental abundance 

and spatial variation in map form and illustrate the different ways in which these types of maps can be 

generated. Reimann (2005) discusses how map design and different mapping techniques can be used to 

optimize the communication of spatial geochemical information.

From 2007 to 2010, the U.S. Geological Survey collected soil samples from 4,857 sites 

throughout the conterminous United States (fig. 1) as part of the North American Soil Geochemical 

Landscapes Project (Smith, 2009; Smith and others, 2009, 2011, 2012; Friske and others, 2013). The

objectives of this project were to (1) produce a soil geochemical and mineralogical database and its 

representation in map form for the continent of North America (21 million square kilometers [km2]), (2) 

interpret the observed geochemical and mineralogical patterns in terms of the processes that caused the 

patterns, and (3) establish an archive of soil samples for use by future investigators. The geochemical 

and mineralogical data for the conterminous United States were published by Smith and others (2013) 

and are available as digital download files at http://pubs.usgs.gov/ds/801/. The purpose of this report is 

to release geochemical and mineralogical maps based on these data as produced using a standardized 

protocol and publicly available GIS software. Only a brief overview of the sampling protocols and 

analytical methods are given below; details are provided in Smith and others (2013).
3

Figure 1. Map showing the location of 4,857 soil sampling sites in the conterminous United States.
4

Sampling

Target sampling sites were selected on the basis of a generalized random tessellation stratified 

design (Stevens and Olsen, 2000, 2003, 2004; Olsen, 2005) at a density of approximately 1 site per 

1,600 km2 (4,857 sites for the conterminous United States). This design produces a spatially balanced 

set of sampling points without adhering to a strict grid-based system.

If a target site was inaccessible for any reason during the sampling program, the field crew 

would select an alternative site as close as possible to the original site with landscape and soil 

characteristics as similar to the original site as possible. The following guidelines were also used in the 

site selection process to ensure that samples were not collected from obviously contaminated areas:

• No sample should be collected within 200 meters (m) of a major highway.

• No sample should be collected within 50 m of a rural road.

• No sample should be collected within 100 m of a building or structure.

• No sample should be collected within 5 kilometers (km) downwind of active major industrial

activities such as power plants or smelters.

The sampling protocols used for the national-scale survey were a combination of depth-based 

and horizon-based sampling. Ideally, the following samples were collected at each site: (1) soil from a 

depth of 0 to 5 centimeters (cm); (2) a composite of the soil A horizon (the uppermost mineral soil); and 

(3) a sample from the soil C horizon (generally partially weathered parent material) or, if the top of the 

C horizon was deeper than 1 m, a sample from about 80 to 100 cm. The specific depths of collection for 

samples from the soil A and C horizons are given in Smith and others (2013).

Chemical Analysis

Each sample was air-dried at ambient temperature, disaggregated, and sieved to <2 millimeters 

(mm). The <2-mm material was then crushed to <150 micrometers (μm) prior to chemical analysis by 

methods that yielded the total or near-total elemental content. Concentrations of aluminum (Al), calcium 

(Ca), iron (Fe), potassium (K), magnesium (Mg), sodium (Na), sulfur (S), titanium (Ti), silver (Ag), 

barium (Ba), beryllium (Be), bismuth (Bi), cadmium (Cd), cerium (Ce), cobalt (Co), chromium (Cr), 

cesium (Cs), copper (Cu), gallium (Ga), indium (In), lanthanum (La), lithium (Li), manganese (Mn), 

molybdenum (Mo), niobium (Nb), nickel (Ni), phosphorus (P), lead (Pb), rubidium (Rb), antimony 

(Sb), scandium (Sc), tin (Sn), strontium (Sr), tellurium (Te), thorium (Th), thallium (Tl), uranium (U), 

vanadium (V), tungsten (W), yttrium (Y), and zinc (Zn) were determined by inductively coupled 

plasma–atomic emission spectrometry (ICP–AES) and inductively coupled plasma–mass spectrometry 

(ICP–MS) following dissolution in a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids. 

Mercury (Hg) was determined by cold-vapor atomic absorption spectrometry after dissolution in a 

mixture of nitric and hydrochloric acids. Arsenic (As) was determined by hydride-generation atomic 

absorption spectrometry following fusion in a mixture of sodium peroxide and sodium hydroxide. 

Selenium (Se) was determined by hydride-generation atomic absorption spectrometry after dissolution 

in a mixture of nitric, hydrofluoric, and perchloric acids. Total carbon (C) was determined by the use of 

an automated carbon analyzer. The concentration of organic C was calculated by subtracting the 

concentration of inorganic (carbonate) C (determined from the mineralogical data for the carbonate 

minerals calcite, dolomite, and aragonite) from the total C concentration. A complete discussion of the 

analytical methods, including quality control protocols, is given in Smith and others (2013).
5

Mineralogical Analysis

All A-horizon and C-horizon samples were analyzed by X-ray diffraction (XRD), and the 

percentages of major mineral phases were calculated using a Rietveld refinement method. The major 

mineral phases reported are quartz, total potassium feldspar, total plagioclase, total feldspar, total 14-

angstrom (Å) clays, total 10-Å clays, kaolinite, total clays, gibbsite, calcite, dolomite, aragonite, total 

carbonates, analcime, heulandite, total zeolites, gypsum, talc, hornblende, serpentine, hematite, goethite, 

pyroxene, pyrite, and amorphous content. Splits of the <2-mm fraction were used for analysis. Zinc 

oxide (ZnO, 10 weight percent) was added to each sample as an internal standard, which allows 

calculation of the amorphous component (portion of sample that is not quantified by the diffraction 

technique). The sample-ZnO mixture was ground for 3 minutes in isopropyl alcohol using a micronizing 

mill and agate beads. Dried samples were disaggregated by passing through a 400-μm sieve and lightly 

pressed into back-loaded sample mounts. Samples were analyzed on a PANalytical X’Pert PRO 

Materials Research Diffractometer using Cu Kα radiation to collect digital data continuously from 3° to 

70° 2θ (scan speed = 0.0567° 2θ per second). PANalytical HighScore Plus software version 2.2a was 

used for pattern processing, mineral phase identification, and Rietveld quantitative mineral analysis. See 

Smith and others (2013) for a complete discussion of the mineralogical analysis and quality control 

protocols used.

Map Generation

In the map figures, the spatial distribution of each element or mineral is shown either by an 

interpolated and smoothed average color surface map or a proportional symbol map. Elements and 

minerals with only a small proportion of samples above the lower limit of determination (LLD) are 

shown as proportional symbol maps; the others are shown as color surface maps.

Interpolated Surface Maps

Maps showing predicted element and mineral concentrations for the conterminous United States 

are interpolated from the actual data points published in Smith and others (2013) by an inverse distance 

weighted (IDW) technique using ArcGIS software. The IDW method used here predicts unique 

concentration values for an array of 444-km2 grid cells covering the conterminous United States 

(approximately 8 million km2

). A weighted average of concentration values for all data points within 75 

km of the center of each grid cell is calculated. The closer a sample point is to the cell being estimated, 

the more influence that point has in the averaging process. The relative influence of closer and more 

distant points can be adjusted by varying a power function. For all of the maps, we have used a default 

value of 2 for the power function, which assigns relatively high significance to the nearest data points. 

Use of this value commonly produces numerous small, circular areas showing the influence of 

individual sample values that vary substantially from neighboring samples and yield a spotted 

appearance of local high and low values. Many of these could be removed by varying interpolation 

parameters to produce a smoother surface. The IDW method is an exact interpolator in which minimum 

and maximum concentrations can occur only at data points, so the interpolated values all lie within the 

range of analytically determined concentrations. To produce the final maps, the array of grid cells 

generated by IDW was further smoothed using a bilinear interpolation to suppress the appearance of 

sharp grid-cell boundaries.

To produce the geochemical maps, samples containing less than the LLD for an element were 

assigned a value of one half of the LLD. For mineralogical data, a nominal LLD of 0.2 weight percent 

was used for all mineral phases that had been quantified, realizing that actual detection limits may have 
6

been higher in cases of severe peak overlap. A value of 0.1 weight percent was assigned to all cases of 

non-detection for each mineral. For approximately half of the geochemical maps, a small number of 

outliers (one to six) were removed prior to the IDW interpolation. Those outliers are extreme high 

concentrations that appear to represent a point source of either natural or anthropogenic origin and are 

not representative of a larger region. If they are included in the interpolation, they produce an 

unrealistically large area of predicted high concentrations and also unduly affect the classification of 

values used in the display. All removed outlier samples are shown as points (diamond symbols) on the 

interpolated maps along with their element concentrations.

As pointed out by Reimann (2005), perhaps the most important step in the construction of an 

informative geochemical map is the choice of classes for color-coding the element concentrations. The 

chosen classes must relate to the statistical distribution of the concentrations if processes governing the 

regional distribution of an element are to be accurately discerned. In accordance with the 

recommendation of Reimann (2005), we have chosen classes on the basis of percentiles of the 

analytically determined values for each element and mineral. The interpolated grid cell values are thus 

portioned into ten classes as follows: 0–10th percentile, 10th–20th percentile, 20th–30th percentile, 

30th–40th percentile, 40th–50th percentile, 50th–60th percentile, 60th–70th percentile, 70th–80th

percentile, 80th–90th percentile, and 90th–100th percentile. Each class is represented by a unique color, 

ranging from blues (lowest concentrations) to reds (highest concentrations). With these classes, each 

color represents approximately 10 percent of the data. For elements having more than 10 percent of 

concentration values below the LLD (Cd [fig. 20D], In [fig. 50D], and Se [fig. 95D] for soils collected 

from a depth of 0 to 5 cm; inorganic C [fig. 28D], Cd [fig. 21D], In [fig. 51D], Hg [fig. 72D], S [fig. 

108D], and Se [fig. 96D] for the soil A horizon; inorganic C [fig. 29D], Cd [fig. 22D], Hg [fig. 73D], In

[fig. 52D], S [fig. 109D], and Se [fig. 97D] for the soil C horizon), the percentile representation was 

modified so that all values below the LLD are included in the lowest concentration class, and the 

remaining values are shown by the appropriate percentile values and colors. On the maps for Cd (figs. 

20D, 21D, and 22D), Hg (figs. 71D, 72D, and 73D), In (figs. 50D, 51D, and 52D), S (figs. 107D, 

108D, and 109D), Se (figs. 95D, 96D, and 97D), and Tl (figs. 113D, 114D, and 115D), some percentile 

classes have been combined because the same concentration represents more than one percentile. This is 

shown clearly on the statistical summary included with each map.

Users of these maps should remember the low-density nature of the data set. The maps represent 

data collected at a density of approximately 1 site per 1,600 km2

, so there is, on average, about 40 km 

between each sample site. Soil geochemistry can vary considerably over that distance, and this variation 

will not be accurately portrayed by the IDW interpolation procedure. This study and the other lowdensity geochemical surveys cited in the Introduction were designed to reveal regional-, national-, and 

continental-scale geochemical and mineralogical patterns extending over thousands or hundreds of 

thousands of square kilometers. The resulting data sets are not appropriate for the accurate estimation of 

the concentration of a given element or mineral at a site where a sample was not collected. To 

paraphrase Blum (2013) in reference to the data for the conterminous United States: The data aren’t so 

fine that they will tell you what lies in your backyard behind the raspberry bush; however, they will 

show you the metal and mineral patterns that color your part of the world and they will remind you—as 

they should—of the astonishing and diverse chemistry that the planet creates under our feet.

Proportional Symbol Maps

Elements and minerals that were detected in less than 30 percent of samples are mapped using 

proportional symbols rather than an interpolated surface. These elements are Ag (figs. 98D, 99D, and 

100D), Cs (figs. 35D, 36D, and 37D), and Te (figs. 110D, 111D, and 112D), and the minerals shown by 
7

this method are gibbsite (figs. 156D and 157D), aragonite (figs. 162D and 163D), analcime (figs. 166D

and 167D), heulandite (figs. 168D and 169D), total zeolites (figs. 170D and 171D), gypsum (figs. 172D

and 173D), talc (figs. 174D and 175D), serpentine (figs. 178D and 179D), hematite (figs. 180D and 

181D), goethite (figs. 182D and 183D), pyroxene (figs. 184D and 185D), and pyrite (figs. 186D and 

187D). They are classified into five concentration ranges, but as with interpolated surfaces, all samples 

with concentrations less than the LLD are grouped into the lowest class.

Explanation of Figures

In the following 188 figures, the geochemical maps (figs. 2D–139D) are presented first and are 

arranged alphabetically by element name (not symbol). For each element (except total C, inorganic C, 

and organic C, which have two maps each), there are three maps representing each of the three soil 

sample types collected (soil from a depth of 0 to 5 cm, soil A horizon, and soil C horizon). These are 

followed by mineralogical maps (figs. 140D–189D) with two maps for each mineral (soil A horizon and 

soil C horizon).

In addition to considering the spatial distribution of an element or mineral as shown on the maps, 

it is important to consider the statistical distribution of the measured concentration values. The statistical 

distribution is shown in three graphics and a table (parts A, B, and C of each figure) accompanying each 

geochemical or mineralogical map (part D of each figure). Part A of each figure is a histogram and a 

table of summary statistics, part B is a Tukey boxplot, and part C is a plot of the empirical cumulative 

distribution function. All three plots are generated with the R statistical computing environment (R Core 

Team, 2013). Each of these graphics, in its own way, allows the determination of whether the data 

distribution is symmetric or skewed, unimodal or multimodal, and whether there are data outliers at 

either extreme of the distribution. The horizontal axis (concentration) is arithmetic except for some 

elements or minerals where the distribution is highly right-skewed. In those cases, a logarithmic scale is 

used. For the histograms, the bin widths are determined by the Sturges formula (Sturges, 1926) when 

the horizontal axis is arithmetic and by the range of the log-transformed data when the horizontal axis is 

logarithmic. Each graph shows the LLD as a red vertical dashed line. Concentrations that are below the 

LLD have been set to a value of one-half the LLD for the graphics. For some elements or minerals (for 

example, Ag), a large percentage of the data are below the LLD; this results in highly distorted plots. 

The median absolute deviation (MAD) and robust coefficient of variation as shown in the summary 

table are not calculated for those elements having more than 5 percent of the analyzed concentrations 

below the LLD. The MAD is scaled by 1.4826 for asymptotically normal consistency.

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11

Figure 2. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
12

Figure 2. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
13

Figure 3. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
14

Figure 3. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
15

Figure 4. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
16

Figure 4. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aluminum (Al) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
17

Figure 5. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
18

Figure 5. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
19

Figure 6. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
20

Figure 6. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
21

Figure 7. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
22

Figure 7. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of antimony (Sb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
23

Figure 8. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
24

Figure 8. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
25

Figure 9. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
26

Figure 9. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
27

Figure 10. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
28

Figure 10. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of arsenic (As) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
29

Figure 11. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
30

Figure 11. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
31

Figure 12. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in the

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
32

Figure 12. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
33

Figure 13. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
34

Figure 13. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of barium (Ba) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
35

Figure 14. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
36

Figure 14. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
37

Figure 15. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
38

Figure 15. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
39

Figure 16. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
40

Figure 16. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of beryllium (Be) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
41

Figure 17. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
42

Figure 17. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
43

Figure 18. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
44

Figure 18. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
45

Figure 19. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
46

Figure 19. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of bismuth (Bi) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
47

Figure 20. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
48

Figure 20. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
49

Figure 21. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
50

Figure 21. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
51

Figure 22. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
52

Figure 22. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cadmium (Cd) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
53

Figure 23. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
54

Figure 23. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
55

Figure 24. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
56

Figure 24. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
57

Figure 25. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
58

Figure 25. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcium (Ca) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
59

Figure 26. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbon (C) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
60

Figure 26. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbon (C) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
61

Figure 27. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbon (C) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
62

Figure 27. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbon (C) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
63

Figure 28. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of inorganic carbon (C) 

in the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

ND, not determined; wt. %, weight percent).
64

Figure 28. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of inorganic carbon (C) 

in the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

ND, not determined; wt. %, weight percent).—Continued
65

Figure 29. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of inorganic carbon (C) 

in the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

ND, not determined; wt. %, weight percent).
66

Figure 29. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of inorganic carbon (C) 

in the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

ND, not determined; wt. %, weight percent).—Continued
67

Figure 30. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of organic carbon (C) 

in the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
68

Figure 30. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of organic carbon (C) 

in the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
69

Figure 31. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of organic carbon (C) 

in the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
70

Figure 31. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of organic carbon (C) 

in the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
71

Figure 32. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
72

Figure 32. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
73

Figure 33. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
74

Figure 33. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
75

Figure 34. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
76

Figure 34. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cerium (Ce) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
77

Figure 35. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
78

Figure 35. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
79

Figure 36. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
80

Figure 36. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
81

Figure 37. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
82

Figure 37. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cesium (Cs) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
83

Figure 38. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
84

Figure 38. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
85

Figure. 39. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
86

Figure. 39. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
87

Figure 40. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
88

Figure 40. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of chromium (Cr) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
89

Figure 41. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
90

Figure 41. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
91

Figure 42. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
92

Figure 42. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
93

Figure 43. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
94

Figure 43. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of cobalt (Co) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
95

Figure 44. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
96

Figure 44. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
97

Figure 45. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
98

Figure 45. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
99

Figure 46. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
100

Figure 46. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of copper (Cu) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
101

Figure 47. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
102

Figure 47. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
103

Figure 48. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
104

Figure 48. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
105

Figure 49. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
106

Figure 49. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gallium (Ga) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
107

Figure 50. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
108

Figure 50. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
109

Figure 51. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).
110

Figure 51. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).—Continued
111

Figure 52. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).
112

Figure 52. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of indium (In) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).—Continued
113

Figure 53. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
114

Figure 53. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
115

Figure 54. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. %, 

weight percent).
116

Figure 54. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. %, 

weight percent).—Continued
117

Figure 55. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. %, 

weight percent).
118

Figure 55. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of iron (Fe) in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. %, 

weight percent).—Continued
119

Figure 56. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
120

Figure 56. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
121

Figure 57. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
122

Figure 57. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
123

Figure 58. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
124

Figure 58. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lanthanum (La) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
125

Figure 59. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
126

Figure 59. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
127

Figure 60. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
128

Figure 60. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
129

Figure 61. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
130

Figure 61. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lead (Pb) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
131

Figure 62. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
132

Figure 62. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
133

Figure 63. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
134

Figure 63. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
135

Figure 64. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
136

Figure 64. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of lithium (Li) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
137

Figure 65. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
138

Figure 65. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
139

Figure 66. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
140

Figure 66. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
141

Figure 67. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).
142

Figure 67. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of magnesium (Mg) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

wt. %, weight percent).—Continued
143

Figure 68. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
144

Figure 68. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
145

Figure 69. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
146

Figure 69. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
147

Figure 70. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
148

Figure 70. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of manganese (Mn) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
149

Figure 71. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
150

Figure 71. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
151

Figure 72. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
152

Figure 72. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
153

Figure 73. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
154

Figure 73. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of mercury (Hg) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
155

Figure 74. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
156

Figure 74. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
157

Figure 75. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
158

Figure 75. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
159

Figure 76. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
160

Figure 76. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of molybdenum (Mo) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
161

Figure 77. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
162

Figure 77. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
163

Figure 78. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
164

Figure 78. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
165

Figure 79. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
166

Figure 79. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of nickel (Ni) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
167

Figure 80. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
168

Figure 80. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
169

Figure 81. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
170

Figure 81. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
171

Figure 82. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
172

Figure 82. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of niobium (Nb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
173

Figure 83. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
174

Figure 83. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
175

Figure 84. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
176

Figure 84. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
177

Figure 85. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
178

Figure 85. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of phosphorus (P) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
179

Figure 86. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
180

Figure 86. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
181

Figure 87. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
182

Figure 87. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
183

Figure 88. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
184

Figure 88. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of potassium (K) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
185

Figure 89. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
186

Figure 89. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
187

Figure 90. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
188

Figure 90. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
189

Figure 91. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
190

Figure 91. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of rubidium (Rb) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
191

Figure 92. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
192

Figure 92. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
193

Figure 93. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
194

Figure 93. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
195

Figure 94. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
196

Figure 94. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of scandium (Sc) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
197

Figure 95. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
198

Figure 95. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
199

Figure 96. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND,

not determined; mg/kg, milligrams per kilogram).
200

Figure 96. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
201

Figure 97. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
202

Figure 97. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of selenium (Se) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
203

Figure 98. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
204

Figure 98. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
205

Figure 99. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).
206

Figure 99. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; mg/kg, milligrams per kilogram).—Continued
207

Figure 100. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
208

Figure 100. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of silver (Ag) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
209

Figure 101. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
210

Figure 101. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
211

Figure 102. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
212

Figure 102. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
213

Figure 103. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
214

Figure 103. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sodium (Na) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
215

Figure 104. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
216

Figure 104. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
217

Figure 105. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
218

Figure 105. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
219

Figure 106. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
220

Figure 106. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of strontium (Sr) in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
221

Figure 107. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; wt. %, weight percent; cm, centimeters).
222

Figure 107. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; wt. %, weight percent; cm, centimeters).—Continued
223

Figure 108. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; wt. %, weight percent).
224

Figure 108. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; wt. %, weight percent).—Continued
225

Figure 109. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; wt. %, weight percent).
226

Figure 109. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of sulfur (S) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, not 

determined; wt. %, weight percent).—Continued
227

Figure 110. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
228

Figure 110. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
229

Figure 111. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
230

Figure 111. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
231

Figure 112. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
232

Figure 112. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tellurium (Te) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
233

Figure 113. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).
234

Figure 113. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; ND, not determined; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
235

Figure 114. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
236

Figure 114. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
237

Figure 115. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).
238

Figure 115. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thallium (Tl) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; ND, 

not determined; mg/kg, milligrams per kilogram).—Continued
239

Figure 116. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
240

Figure 116. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
241

Figure 117. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
242

Figure 117. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
243

Figure 118. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
244

Figure 118. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of thorium (Th) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
245

Figure 119. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
246

Figure 119. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
247

Figure 120. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
248

Figure 120. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
249

Figure 121. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
250

Figure 121. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tin (Sn) in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
251

Figure 122. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).
252

Figure 122. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; wt. %, weight percent; cm, centimeters).—Continued
253

Figure 123. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
254

Figure 123. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).—Continued
255

Figure 124. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt. 

%, weight percent).
256

Figure 124. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of titanium (Ti) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; wt.

%, weight percent).—Continued
257

Figure 125. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
258

Figure 125. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
259

Figure 126. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
260

Figure 126. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
261

Figure 127. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
262

Figure 127. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of tungsten (W) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
263

Figure 128. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
264

Figure 128. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
265

Figure 129. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
266

Figure 129. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
267

Figure 130. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
268

Figure 130. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of uranium (U) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
269

Figure 131. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
270

Figure 131. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
271

Figure 132. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
272

Figure 132. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
273

Figure 133. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
274

Figure 133. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of vanadium (V) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
275

Figure 134. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
276

Figure 134. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in 

surface soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
277

Figure 135. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
278

Figure 135. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
279

Figure 136. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).
280

Figure 136. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of yttrium (Y) in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; 

mg/kg, milligrams per kilogram).—Continued
281

Figure 137. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).
282

Figure 137. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in surface 

soils collected from a depth of 0 to 5 centimeters, conterminous United States (LLD, lower limit of determination; MAD, median absolute 

deviation; CV, coefficient of variation; mg/kg, milligrams per kilogram; cm, centimeters).—Continued
283

Figure 138. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
284

Figure 138. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
285

Figure 139. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).
286

Figure 139. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of zinc (Zn) in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; MAD, median absolute deviation; CV, coefficient of variation; mg/kg, 

milligrams per kilogram).—Continued
287

Figure 140. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of quartz in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
288

Figure 140. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of quartz in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
289

Figure 141. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of quartz in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
290

Figure 141. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of quartz in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
291

Figure 142. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total potassium 

feldspar (K-feldspar) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
292

Figure 142. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total potassium 

feldspar (K-feldspar) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
293

Figure 143. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total potassium 

feldspar (K-feldspar) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
294

Figure 143. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total potassium 

feldspar (K-feldspar) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
295

Figure 144. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total plagioclase in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
296

Figure 144. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total plagioclase in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
297

Figure 145. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total plagioclase in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
298

Figure 145. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total plagioclase in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
299

Figure 146. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total feldspar (total 

potassium feldspar + total plagioclase) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight 

percent).
300

Figure 146. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total feldspar (total 

potassium feldspar + total plagioclase) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight

percent).—Continued
301

Figure 147. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total feldspar (total 

potassium feldspar + total plagioclase) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight 

percent).
302

Figure 147. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total feldspar (total 

potassium feldspar + total plagioclase) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight 

percent).—Continued
303

Figure 148. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 14-Å clays in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).
304

Figure 148. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 14-Å clays in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).—Continued
305

Figure 149. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 14-Å clays in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).
306

Figure 149. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 14-Å clays in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).—Continued
307

Figure 150. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 10-Å clays in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).
308

Figure 150. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 10-Å clays in 

the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, weight percent).—Continued
309

Figure 151. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 10-Å clays in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom). MAD, median absolute deviation; ND, not 

determined; CV, coefficient of variation; mg/kg, milligrams per kilogram.
310

Figure 151. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total 10-Å clays in 

the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom). MAD, median absolute deviation; ND, not 

determined; CV, coefficient of variation; mg/kg, milligrams per kilogram.—Continued
311

Figure 152. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of kaolinite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
312

Figure 152. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of kaolinite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
313

Figure 153. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of kaolinite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
314

Figure 153. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of kaolinite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
315

Figure 154. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total clay (total 14-

Å clays + total 10-Å clays + kaolinite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, 

weight percent).
316

Figure 154. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total clay (total 14-

Å clays + total 10-Å clays + kaolinite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, 

weight percent).—Continued
317

Figure 155. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total clay (total 14-

Å clays + total 10-Å clays + kaolinite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, 

weight percent).
318

Figure 155. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total clay (total 14-

Å clays + total 10-Å clays + kaolinite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; Å, angstrom; wt. %, 

weight percent).—Continued
319

Figure 156. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gibbsite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
320

Figure 156. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gibbsite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
321

Figure 157. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gibbsite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
322

Figure 157. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gibbsite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
323

Figure 158. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcite in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
324

Figure 158. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcite in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
325

Figure 159. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcite in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
326

Figure 159. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of calcite in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
327

Figure 160. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of dolomite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
328

Figure 160. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of dolomite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
329

Figure 161. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of dolomite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
330

Figure 161. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of dolomite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
331

Figure 162. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aragonite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
332

Figure 162. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aragonite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
333

Figure 163. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aragonite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
334

Figure 163. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of aragonite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
335

Figure 164. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbonate 

(calcite + dolomite + aragonite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
336

Figure 164. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbonate 

(calcite + dolomite + aragonite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—

Continued
337

Figure 165. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbonate 

(calcite + dolomite + aragonite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
338

Figure 165. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total carbonate 

(calcite + dolomite + aragonite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—

Continued
339

Figure 166. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of analcime in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
340

Figure 166. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of analcime in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
341

Figure 167. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of analcime in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
342

Figure 167. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of analcime in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
343

Figure 168. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of heulandite in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
344

Figure 168. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of heulandite in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
345

Figure 169. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of heulandite in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
346

Figure 169. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of heulandite in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
347

Figure 170. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total zeolites 

(analcime + heulandite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
348

Figure 170. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total zeolites 

(analcime + heulandite) in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
349

Figure 171. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total zeolites 

(analcime + heulandite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
350

Figure 171. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of total zeolites 

(analcime + heulandite) in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
351

Figure 172. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gypsum in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
352

Figure 172. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gypsum in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
353

Figure 173. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gypsum in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
354

Figure 173. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of gypsum in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
355

Figure 174. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of talc in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
356

Figure 174. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of talc in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
357

Figure 175. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of talc in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
358

Figure 175. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of talc in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
359

Figure 176. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hornblende in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
360

Figure 176. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hornblende in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
361

Figure 177. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hornblende in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
362

Figure 177. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hornblende in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
363

Figure 178. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of serpentine in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
364

Figure 178. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of serpentine in the 

soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
365

Figure 179. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of serpentine in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
366

Figure 179. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of serpentine in the 

soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
367

Figure 180. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hematite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
368

Figure 180. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hematite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
369

Figure 181. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hematite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
370

Figure 181. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of hematite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
371

Figure 182. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of goethite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
372

Figure 182. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of goethite in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
373

Figure 183. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of goethite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
374

Figure 183. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of goethite in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
375

Figure 184. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyroxene in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
376

Figure 184. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyroxene in the soil 

A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
377

Figure 185. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyroxene in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
378

Figure 185. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyroxene in the soil 

C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
379

Figure 186. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyrite in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
380

Figure 186. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyrite in the soil A 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
381

Figure 187. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyrite in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
382

Figure 187. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of pyrite in the soil C 

horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
383

Figure 188. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of amorphous 

component in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
384

Figure 188. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of amorphous 

component in the soil A horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued
385

Figure 189. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of amorphous 

component in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).
386

Figure 189. A, Histogram and summary statistics; B, Boxplot; C, Empirical cumulative distribution function; and D, Distribution of amorphous 

component in the soil C horizon, conterminous United States (LLD, lower limit of determination; wt. %, weight percent).—Continued

ISSN 2331-1258 (online)

http://dx.doi.org/10.3133/ofr20141082