Magnetic Fields for a 

4x6 Prismatic Model

By GORDON E. ANDREASEN and ISIDORE ZIETZ

GEOLOGICAL SURVEY PROFESSIONAL PAPER 666

A collection of 825 contoured magnetic fields 

for a 4x6 (depth units) prismatic model for 

various thicknesses, directions of polar i% at ion, 

and inclinations of the earth s field

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1969
UNITED STATES DEPARTMENT OF THE INTERIOR 

WALTER J. HICKEL, Secretary

GEOLOGICAL SURVEY 

William T. Pecora, Director

Library of Congress catalog-card No. 70-650232

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 - Price $4.25 cents (paper cover)
CONTENTS

Abstract___.___________-__________________-______--__---_---_------_-_-__ 1

Introduction. ______________________________________________________________ 1

Acknowledgments.___________________________________ ___________________ 1

The model--_________________-________________________ __ 1

Contoured magnetic fields ________________________________________________ 3

Procedure --_--------------------_-__-__-_---_-_-------------_------_ 3

Computer program in FORTRAN IV_ ________________________ 4

Model description_____________________________________________________ 8

References cited-_____________________________________ ___________________ 9

ILLUSTRATIONS

[Plates follow "References cited"]

Page 

PLATES 1-210. Contoured magnetic fields:

1-42. Prismatic model 4 X 6 X. 1. 

43-84. Prismatic model 4X6X.25. 

85-126. Prismatic model 4X6X.5. 

127-168. Prismatic model 4X6X 1.0. 

169-210. Prismatic model 4X6X «. 

FIGURE 1. Rectangular prism showing elemental volume ________-__---__ __ 2

2. Diagram showing total polarization__-___-_-_--_-__--------_------- 2

in

MAGNETIC FIELDS FOR A 4X6 PRISMATIC MODEL

By GORDON E. ANDREASEN and ISIDORE ZIBTZ

ABSTRACT

Magnetic fields have been computed for 4X6 (depth units) 

prismatic models with thicknesses ranging from 0.1 depth unit 

to infinity. For each model, the azimuth and inclination of 

polarization have been systematically varied from 0° to 90° 

and from 0° to 150°, respectively. In addition, the fields were 

computed for inclinations of the earth's field ranging from 

0° to 90°. The computation and contouring of the fields were 

accomplished by high speed digital computers and automatic 

data plotters. Both formulation and program listing are included.

The 825 magnetic fields that make up this 4X6 model include 

the induced case and the remanent magnetization case. This 

suite of fields is primarily designed to aid the investigator in the 

geologic interpretation of observed magnetic anomalies.

INTRODUCTION

The usefulness of magnetic models in the geologic 

interpretation of anomalies resulting from induction in 

the earth's field has been well established (for example, 

Vacquier and others, 1951; Zietz and Henderson, 1956). 

These models often aid the investigator in determining 

such important parameters as areal extent of the 

anomaly-producing rock mass, the depth of burial of 

its upper surface, and the apparent magnetic susceptibility. However, the time-consuming laboratory measurements required for model preparation precluded 

publishing models in sufficient numbers so as to be of 

wide use. Also, it is now known that many rock units 

of large areal extent possess strong components of 

remanent magnetization that are not codirectional 

with the earth's field (Green, 1960; Watkins, 1961; 

Books, 1962; DuBois, 1962, 1963; Zietz, 1961; Zietz 

and Andreasen, 1967); in such cases Vacquier models 

(Vacquier and others, 1951) are not applicable.

With the advent of high speed digital computers, 

magnetic fields for prismatic models can be calculated 

quickly and effortlessly by an exact mathematical 

formula and then contoured automatically by mechanical or cathode-ray plotters. The authors have used this 

approach (Zietz, 1961) to generate an extensive collection of magnetic models that will not only be a sizable 

addition to the induced case but will also be a systematic 

tudy of the remanent fields caused by varying directions of magnetization. A similar approach 1 as been 

used by Bhattacharyya (1964). He calculated several 

magnetic fields for prismatic bodies using an arbitrary 

direction of magnetization; these fields wer^ subsequently hand-contoured. This report includes 825 

magnetic fields representing various directions of 

polarization, earth's field, and model thicknesses for a 

specific model. Only the total polarization or vector sum 

is considered, and no differentiation is made between 

the induced and remanent polarization. If the remanent 

polarization relative to the induced polarization is small, 

the formula reduces to the case for induced pokrization, 

and the three-dimensional magnetic fields generated 

would be similar to the Vacquier models, differing only 

by the demagnetization factor.

ACKNOWLEDGMENTS

The authors are especially grateful to Mr. James 

Nielon, U.S. Weather Bureau, for modifying the curve 

follower program for automatic contouring of the magnetic data, and to Dr. Joseph Cain, Goddard Space 

Flight Center, whose continued interest has made the 

project possible.

THE MODEL

The magnetic model is a prism assumed to be a 

rectangular block with an upper surface or 0* depth 

unit below the x-y plane of observation (fig. 1). The 

length, width, and thickness of the prism are expressed 

in depth units. The prism is further assumed to be 

made up of elementary dipoles all aligned in the same 

direction and possessing the same magnetic moment. 

The potential AF at any point P (x,y,z) due to an 

elemental volume dv dx'dy'dzf at a distance r and 

a total polarization Jt is

The potential due to the entire body is

fJfTj

~Jv r* (1)
MAGNETIC FIELDS FOR A 4X6 PRISMATIC MODEL

P (*. y, z)

MAGNETIC 

NORTH

MAGNETIC 

NORTH

EXPLANATION

J, = total polarization

S = azimuth of to*al polarization

t =dip of total polarization

FIGUBB 1. Rectangular prism showing elemental volume.

The polarization Jt is the vector sum of the polarization (J<) resulting from induction in the earth's field 

and the remanent polarization (Jr), that is,

(2)

The direction of Jt is defined by two angles, t and 5, as 

shown in figure 2. The axes of the rectangular coordinate system are chosen so that the z axis is directed

FIGURE 2. Total polarization, Jj.

positively downwards and the x axis is in tte direction 

of magnetic north. 

Completing the scalar product in equatior 1,

(3)

where 6 is the angle between Jt and r, and

<tos 0=- - cos 5 cos t

I r

Substituting,

T/~Jv = fJt[ x') cos 5 cos i+(y y') sin 5 cos t+(z z'} sin (4)

where

r+(y-y')2+ (zThe component of magnetic intensity in the direction 

of the earth's field, that is, the value measured by a 

total field magnetometer is

parameters may be eliminated and the field normalized

\T

by computing the ratio -j- which is dependent only «/j

upon the geometry of the magnetic mass (Zietz and 

Henderson, 1956). Equation 6 becomes

=Az cos 7+A2 sin /, (5)

AT__5_ 

Jt ox' (7)

where 7 is the angle of dip of the earth's magnetic 

field. As

"^ ~~~c j' and TT *^x T 

ox ox' <* M *"'

equation 5 becomes

w »v . T -^^sin7

The substitution of equation 4 into equation 7 yields

&T f Cr o

JT= \ J,Lcos 5 . cos

°V

cos (6)

+sin t7

+sin 5 cos

COS 8 COS t7

, (8)

The anomalous field AT contains parameters of the 

inducing field (H), the susceptibility of the magnetizable 

material (k), and the remanent polarization (JT). The

Upon reducing the volume integral to a surface 

integral and integrating, the final expression for 

normalized field at any point in the x-y plane
CONTOURED MAGNETIC FIELDS

-=cos i cos 5 cos /

x oil

x-ai

+tan~

x x 

(y-&)7i

 tan (x- }

+sin t cos I-I tan

 tan

4-sin +sii cos

-snsm

+ tan~ 

(x-a2)(y-]8i)

11/2

 tan (aj oi)(y |

7l[(x-a1) 2+(y-l82) 2+7i2]1/2

cos /1

cos i cos 5 sinm

+cos i cos 5 sin

-cos t sin 5 cos

(r-&)+[(*-«2) 2+(y-02) 2+7i2r

+cos t sin S cos / log

. , . rl (z

 cos t sm 5 sin / log) &

_jg \2_i_ 2ii/2

 j8o2) 2 +7i21/2 ]1/2

+cos J. sm,n

 

 

* 1/2 ]8i) 2+7i2]1/2

(^-«2)+[(a:-«2) 2+(y-|8a) 2+7iT/2

(9)

Equation 9 is an exact expression for the normalized 

field due to a rectangular magnetic prism at any point 

in the ;e-y plane. If the remanent polarization should be 

zero, the equation reduces to an expression for a 

normalized field caused by induction only.

CONTOURED MAGNETIC FIELDS 

PROCEDURE

The magnetic field* for each prism is based on the 

evaluation of equation 9 at 1,369 grid points in the 

plane of observation. The computation tune using a 

direct-coupled IBM 7040-7094 computer is le^s than 5 

seconds. Another computer program which is a modification of the curve-follower program developed by the 

U.S. Weather Bureau interpolates the data vhich are 

automatically contoured on an Electronic Associates 

Inc. model 3410 Dataplotter. The interpolation process 

requires about 10 seconds of computer t:\me, and 

contouring requires approximately 2 minutes.

The original contoured magnetic fields covered an 

area of 18 by 18 inches and were drawn on semitransparent paper. These were used as overlays on 18- by 

18-inch grids on which the model location was delineated 

by heavy lines. The contours, magnetic highs and lows, 

the three angles (5, i, 1} , and thickness were haE d labeled.
MAGNETIC FIELDS FOR A 4x6 PRISMATIC MODEL 

COMPUTER PROGRAM IN FORTRAN IV

SIBFTC MODEL DECK

C MAGNETIC MODEL STUDIES IN FCRTRAN IV

DIMENSION COEFAC65.65 ) , COEF8( 65 ,65 ) ,COEFC( 65, 65 ) ,CCEFD( 65 ,65) , 

1CCF.FE ( 5,65) ,AL(2) ,8E( 2) ,GA(2) ,GAS ( 2 ) , ALMX (2 ) , ALMX S( 2) ,BEMY<2) , 

2BEMYS(2),RHO(2,2,2) ,Z (65) , IER(9)

EGUIVALENCE (AL( 2) ,RH),(flE( 1 ) ,RV ), (BE<2 ) ,RI ) 

11 FCRKAT (14, II ,5F5»2 ,E8. 2.5F5.2, 16)

REWIND 10 

C READ INPUTS

1 REAO(5,11) IREF,IO,AL(1),AL(2),BE(1|,BE<2),GA(1),GA(2), 

1 XI,X2,DXY,Y1,Y2,MAFIC 

IF UD-2)2, 310,2

2 DO 2 1=1.9

3 IER(I)=0

IF( IC-114,9,5

4 IER(9)=9 

GO TO 30

5 IF (ID-9) 6,3000,6

6 IER(^) = 9

GO TO 30

C FOIT PARAMETER CARD 

9 IF (AL( 2|-AL( 1) ) 12, 11,14

13 IERUM1

14 IF (EE(2|-BE< 1) )15, 15, 1 

15 IFR(2)=2

16 IF (GA( 1)-0.) 17, 17, 18

17 IER(3M3

18 IF (GA(2)-GA(1))19,1<3,20 

3 2

20 IF (GA(2)-1.0E17)22,21,?1

21 IER(5) = 5

22 IF (CXY)23,23,24

23 IER(6)=6

24 IXL= ABS (( X2-XU/DXY) & 1.0

IF (IXL-2 ) 25,2600,260C 

2600 IFMXL-65) 26,25,25

25 IER(7)=7

26 IYL = ABS ( (Y2-Y1)/DXY) & 1.0

IF(IYL-2)27,2800,28CO 

2800 IF (IYL-65) 28.27,27

27 IER(8)=8

28 CONTINUE

30 DO 31 1= 1,9

IF (IERU ) ) 31 ,31 ,32

31 CONTINUE

WRITE(6.34|

1 IR£F,ID,AL( 1) ,AL( 2),BE( 1).BE( 2 ) . GA ( 1) .GA(2) .XI ,X2,OXY, 

1 Y1.Y2 

34 FCRVAT (1H1 ,215,5F6.2»E10.2 ,5F5.2,14H PAR^M CARD OK)

GO 1O 50 

32 WRITE(6,33)

1 I REF,ID,AL( 1),AL(2),BE(1),BE(2) ,GA(1 ),GA(2),X1,X2,DXY» 

1 Y1,Y2,(IER(I),1=1,^)
CONTOURED MAGNETIC FIELDS

33 FORMAT ( 1 Hi , 215 * 5F6. 2,E 10 . 2, 5F6.2, 91 2. 1 2H PARAM ERROR) 

IREF1 = 0 

GO TO 1

50 GAS<1) = GA<1) * GA<1)

WRITE(6.51) IXL,IYL

51 FORMAT < 1HO ,4HIXL = , I3,4X,4HI YL= ,13) 

GAS(2) = GA(2) *GA(2) 

HLFFI=1.5707963 

PI = 3. I 41 592 7 

IFEF1 = IREF 

Y = Yi - CXY 

DC 112 IY = I.I YL 

Y = Y & OXY

00 62 I = 1 ,2 

EEMY< I) = BE( I ) -Y

62 BEMYS(I) = BEMY(I) *BEMY(1) 

X = XI - OXY

60 DC 112 IX = I.I XL 

X = X & DXY

00 61 1=1,2 

ALMX( I) = AL( I ) - X

61 ALMXS(I) = ALMX(I) * ALMX<I) 

00 65 I = 1*2 

DC 65 J = 1.2 

DO 65 K = 1.2

65 RHQ (I,J,K) = SORT (ALMXS(I) & 8EMYS(J) & GAStK)) 

72 = 0, 

SLV = 0, 

IF ( ALMX( 1 ) ) 66,78,66

66 OC 77 J = 1,2 

CO 77 K =1,2

F = (BEMY(J) * GA(KM / (ALMXI1) * PhQ(t«J.K}| 

IF ( MUD <J&K,2)-1) 68,67,68 

 7 F s -F

68 Gl = ZZ & F

G2 = 1.0 - ZZ*F 

IF (02) 73,69,73

69 IF (Ql) 70,71,71

70 SUM = SUM - HLFPI 

GO TO 72

71 StM s SUM & HLF^I

72 77 = 0.

GO TO 77

73 27 - Ql / Q2

IF <Q2) 74,77,77

74 IF {Ql) 75,76,76

75 SUM = SUM - PI 

GC TO 77

76 SUM = SUM & PI

77 CONTINUE

78 IF(ALMX(2))40,90,40 

40 OC 89 J = 1,2

DO 89 K SB 1 ,2

F a (BEMY(J) * GACK)) / (ALMX(2) * RHG(2.J,K))
MAGNETIC FIELDS FOR A 4X6 PRISMATIC MODEL

IF ( MOO (J&K,2)) 8C»79,8Q

79 F = -F

80 Gl = ZZ & F

02 =1.0 -ZZ*F

IF (Q2J 85,81,85

81 IF < Ql) 82,83,83

82 SUM = SUM - HLFPI 

GO TO 84

83 SUM = SUM & HLFPI

84 22 a 0.

GO TO 89

85 ZZ = Ql / Q2

IF ( Q2 \ 86,89,89

86 IF (Ql ) 87,88,83

87 SUM = SUM - PI

GO TO 89 

R8 SUM = SUM & PI

89 CONTINUE

90 CC^FACI X, I Y) = ATAN <7Z)£ SUM 

U = 1 .0

DO 93 I = I ,2 

CO 93 J = 1 ,2 

DO 93 K = 1 ,2 

FAC = RHO(I,J,K) C EEMY(J) 

IF ( MOO (I&J&K«2)) 92,91,92

91 t = U * FAC 

GO TO 93

92 U = U / FAC

93 CONTINUE

CCEFB(IX,IY) = ALOG(U) 

U = i.O

DC 96 I = 1,2 

CO 96 J = 1 ,2 

DO 96 K = 1 ,2 

FAC = RHO(I,J,K) & GA(K) 

IF ( MOD ( I&J&K,2) )95»94,95

94 t = U * FAC 

GO TO 96

95 U = U / FAC

96 CONTINUE

97 CCFFC(IX,IY) = ALOG(U) 

U = 1.0

DC 100 I = 1,2 

CO 100 J = 1,2 

DO 100 K = 1,2 

FAC a RHO(I«J,K) 6 ALMX(I) 

IF ( MOD (I&J&K,2)) 99,98,99

98 t = U * FAC 

GO TO 100

99 U = U / FAC 

100 CONTINUE

CCFFD(IX,IY) = ALCG(U» 

ZZ = 0. 

SCM = 0.
CONTOURED MAGNETIC FIELDS

DO 111 I = 1,2 

00 111 J = 1.2 

CO 111 K = 1 ,2

F s (ALMX(I) * BFMY(J)) / (GA(K) * RHO(I.J.K)) 

IF( MOD (I&J&K.2)) 102.1C1.1C2

101 F = -F

102 Ql « ZZ & F

Q2 = 1. 0 -ZZ*F

IF (Q2) 107.103.107

103 IF (Ql) 104.105,105

104 SUM = SUM - HLFFI

GO TO 106

1 C5 SUM = SUM & HLF^I 

1C6 77 - 0.

GO TO 111

107 ZZ = Ql / Q2

IF (Q2) 108, 111,111

108 IF (Ql) 109,110, 1 10

109 SUM = SCM - PI 

GO TO 111

110 SUM = SUM & PI

111 CONTINUE

112 COEFE(IX.IY) = ATJN < ZZ )& SUM 

GC TC 1 

PROCESS ANGLE CARD

310 MP = (AL(1) 6S1GN(O.C05. ALU ) ) )*1CO. 0 

IF (IREF1 - IREF) 400.311,400

311 WPITE(6,329)

1 IREF.ID.MF.RH.RV.RI.MAPID 

329 FORMAT (1 HO *315,3F5.2,2X.16 ) 

360 R*R*D = 0.017453293 * RH * 10.0

-648 7 4 -87 33

CCSRH = COS (RHRAD)

RVRAD = 0.017453293 * RV * 10.0

SINKV a SIN (RVRAD)

CCSRV = COS (RVRAD)

RIRJD = 0.017453293 * RI * 10.0

SINRI = SIN (RIRAD) 

COSRI = COS (RIRAD) 

TPGA = COSRH * COSRV * COSRI 

TRGE = SINRV * COSRI & CCSRH * COSPV * SINRI 

TRGC « SINRH * COSRV * CCSRI 

TRGC = SINRH * COSRV * SINRI 

TRGE = SINRV * SINRI

WRITE(6,331 ) TRGA.TRGB.TRGC.TRGD .TRGE 

331 FCRWAT (1H0.5E15. 8. 12H TRG FACTORS)

ZWAX=-0.9E&36 

ZHK= 0.9E&36 

IX = IXL

¥(RITF(10) MAP ID, I XL . IYL 

220 DC 241 IY=1 ,1 YL

Z( IY)=TRGA*COEFA( IX, IY) 6TRGfi*COEFB( IX, I Y )&TRGC*CDEFC( IX, I Y) 

1 &TRGQ*COEFO( IX, I Y) &TRGF*COEFE( IX, I Y) 

IF (ZUY) .LT. ZMIN) ZMIN^Z(IY)
8 MAGNETIC FIELDS FOR A 4x6 PRISMATIC MODEL

341

GT. ZMAX) 7MAX=Z(IY) 

Z< J) ,J = 1 ,1 YL)

344 ZMAV =

IF <Z(IY) , 

CCNTINUE 

WPITE(IO) i 

1 = 1 XL-I X&l 

IX-IX-1

IF ( IX .GE, 1 ) GO TO 320

WPITF<6»344) MAPI). I XL. IYL,ZMAX.ZMIN

FORMAT* 10HO MAP ID = ,I6,I4.5H RCVKS,I4,8H COLUMNS,5X,8H 

1 1PE14.7.9H ZMIN = .1PE14.7) 

GO TO I

400 IF (IREF1) 403,401,403

401 WRITEC6.402)

i IREF,ID,MP,RH,RV,R UMAPTD

402 FCRMAT ( 1HO ,3I 5,3F5.2 ,2X,I 6,31H PARAM ERROR - MAO NOT COMPUTED) 

GC TC 1

403 WPITE(6.4C4)

404 FORMAT (1HO,34H DIFFERENT REF NOS, - MAP COMPUTED)

GC TC 311 

3000 END FILE 10 

REWIND 10 

STOP 

END

MODEL DESCRIPTION

The present magnetic model is a prism measuring 

4 depth units in.the magnetic north direction and 6 

depth units in the magnetic east direction. The thicknesses (t) in depth units are 0.1, 0.25, 0.5, 1.0, and 

infinity. The inclination of the earth's magnetic field 

(7) is assumed to be 0°, 30°, 60°, 75°, and 90°. For each 

prism thickness (t) and each earth's field (J), the declination or azimuth (8) of the polarization vector takes 

on the values 0°, 30°, 60°, and 90°. And for each declination there are associated nine inclinations (i) of the 

polarization vector. These are: 0°, 20°, 30°, 45°, 60°, 

75°, 90°, 120°, and 150°. The magnetic fields for the 

4X6 model are grouped according to the thickness (t) 

of the prism, the thinnest (0.1) appearing first. Within 

each thickness group, the fields are arranged according 

to the earth's field (7=0°, 30°, 60°, and 90°). Then for 

each earth's field in a particular thickness group, the 

declination (8) of the polarization vector varies from 

0° to 90° (in 30° steps). Finally, for each polarization 

declination the polarization inclinations (i) vary from 

0° to 150° in the nine increments specified above.

There is one exception to the above order of fields. 

For a particular t and 7, the fields resulting from setting 

i=90° are obviously independent of 5. Because four 

different values of 7 are used, four identical fields would 

result. Only one of these fields, corresponding to 

8=0°, is shown.

The user may turn readily to a desired field by first 

selecting appropriate thickness shown in the lower left

hand corner of each plate. Under each contc Tired field 

three angles are shown 5, i, and 7. The u^er would 

choose the value of 7 (inclination of earth's field) that 

most nearly coincided with the value of 7 for his area. 

He is then ready to select the contoured field corresponding to one or more directions of polarization 

as may suit his purposes.

The use of the 4X6 models in the interpretation of 

observed magnetic anomalies is beyond the scope of 

the present publication. However, the reader is referred 

to a recent paper by Zietz and Andreasen (1967) 

describing a method of determining remanent directions 

from operations on the observed field only. Tl °- method 

is based upon empirical relationships between the 

physical prism and the computed field.

Although the production of the magnetic fields shown 

in this publication was made feasible by the use of a 

high speed computer and mechanical contouring device, 

the relative time-consuming task of hand labeling and 

the two-step photographic reduction process stimulated 

a quest for a system that would eliminate entirely all 

hand processing of the data, except the initial input 

describing the desired field.

Such a system was found in a contour program 

obtained from Dr. Joseph Cain of the Goddard Space 

Flight Center. The output from the contour program 

was modified for the SC-4020 (Stromberg-Carlson) 

cathode-ray plotter. The program generates the contours, grid, model outline, and all labeling. The resulting 

complete field is displayed in a matter of seconds on
CONTOURED MAGNETIC FIELDS 9

the cathode-ray tube from which a 35-millimeter film

I positive is obtained. Subsequent models are now in 

preparation utilizing the cathode-ray system.

REFERENCES CITED

Bhattacharyya, B. K., 1964, Magnetic anomalies due to prismshaped bodies with arbitrary polarization: Geophysics, v. 29, 

no. 4, p. 517-553.

Books, K. G., 1962, Remanent magnetism as a contributor to 

some aeromagnetic anomalies: Geophysics, v. 27, no. 3, p. 

359-375.

DuBois, R. L., 1962, Magnetic characteristics of a massive 

hematite body: Jour. Geophys. Research, v. 67, no. 7, p. 

2887-2894.

 1963, Remanent, induced, and total magnetism of a suite 

of serpentine specimens from the Sierra Nevada, California: 

Jour. Geophys. Research, v. 68, no. 1, p. 267-278.

Green, R., 1960, Remanent magnetization and the interpretation 

of magnetic anomalies: Geophys. Prosp., v. 8, no. 1, p. 

98-110.

Vacquier, Victor, Steenland, N. C., Henderson, R. G., and Zietz, 

Isidore, 1951, Interpretation of aeromagnetic m<vos: Geol. 

Soc. America Mem. 47, 151 p.

Watkins, N. D., 1961, The relative contributions of remanent 

and induced magnetism to the observed magnetic field in 

northeast Alberta: Geophys. Prosp., v. 9, p. 421-426.

Zietz, Isidore, 1961, Remanent magnetization and aeromagnetic 

interpretation jabs.]: Soc. Explor. Geophysicists Yearbook, 

235 p.

Zietz, Isidore, and Andreasen, G. E., 1967, Remanent magnetization and aeromagnetic interpretation, in Mining geophysics Volume 2, Theory: Tulsa, Okla., Soi. Explor. 

Geophysicists, p. 569-590.

Zietz, Isidore, and Henderson, R. G., 1956, A prelimirary report 

on model studies of magnetic anomalies of three-d?Txxensional 

bodies: Geophysics, v. 21, no. 3, p. 794-814.

CONTOURED MAGNETIC FIELDS

PLATES 1-210

UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 1

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

6=Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 2
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 2

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

J=Declination o' polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 3

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X1

Grid interval = Depth of burial MAGNETIC NORTH

8 = Declination of polarization 

i = Inclination of polarization 

1= Inclinati on of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 666 

PLATE 4

8= 30* 1=60" 1=0'

6= 30'i=75° 1=0"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MOBEL = 4X6X .1

Grid intervals Depth of burial MAGNETIC NORTH

120-

8=30* i=120* 1=0*

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of e?rthc field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 5

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X j

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL FAPEE 666 

PLATE f

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X ,

Grid interval = Depth of buri . MAGNETIC NORTH

5=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 7

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.i

Grid mterval = Depth of buria' MAGNETIC NORTH

6=Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 8

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X j.

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PL.ATE 9

00=

^05i

X+.1

S= 90' t=150*I=0 5=0* i=0° 1=30*

H-.013

43 

100-

8=0* i=20" 1=30'

TOTAL MAGNETIC INTENSITY, AT/J. (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

8= 0* t= 30' 1= 30*

5=Declination of polarization 

(=lnclinat'on of polarization 

1= Incltnat'^n of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 10

3= o° '=45° 1= 30° 8= 0° i= 60° 1= 30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval=Depth of burial (MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 11

&= 0° i= 120° 1= 30° 8= 0" t= 1501= 30"

-KlDS

8= 30°<= 0° 1= SOTOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X .1

Grid interval = Depth of burial MAGNETIC NORTH

-05C

8=30°t=20° 1= 30°

S= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL FAPER 

PLATE 12

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X .1

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 13

8=30° i=l 50° 1=30°

+.08i)

±04

XH.026

8=60° i=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X .1

Grid interval = Depth of burial. MAGNETIC NORTH

8= 60° i= 20° 1= 30°

:-.087

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTEBIOB 

GEOLOGICAL SUBVEY

PBOFESSIONAL TAPES 

PLATE 14

8= 60° i=45° 1= SOTOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6X1

Grid interval = Depth of burial, MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 15

S= 60° i= 120° 1= 30° 5= 60° i= 150° 1= SOTOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X a

Grid interval = Depth of burial MAGNETIC NORTH

g= Declination of polarization 

1= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 16

*'c»

-092

V*

i!

*=90*t=30* 1=30° 5= 90"t=45* 1= 30°

+.390,

5= 90° =60° 1=30'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval = Depth of burial. MAGNETIC NORTH

8= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 17

-070

5=90° t= 120° 1= 30' 5= 90°i=150°I= 30°

+.146-

5=0° i= 0° 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial

5= Declination of polarization 

t=lnclination of polarisation 

1= Inclination of earths field

MAGNtTIC NORTH

334-908 0-69-3
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIOrAL PAPER 666 

PLATE 18

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declinaton of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OP THE INTERIOR 

GEOLOGICAL SUBVET

PROFESSIONAL PAPER 666 

PLATE 19

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEt=4X6Xa

Grid interval = Depth of burial MAGNETIC NORTH

j= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OF THE INTEEIOB 

GEOLOGICAL SUBVEY

PBOFESSIONAL PAPEB 666 

PLATE 20

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval = Depth of burial MAGNETIC NORTH

g= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 666 

PLATE 2<

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

1 = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 22

8=60° i= 20° 1= 60° 8= 60*i= 30*1= 60°

K-JOJ8

a=60°t= 45° 1= 60*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X1

Grid interval=Depth of burial MAGNETIC NORTH

8= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OP THE INTEBIOB 

GEOLOGICAL SUBVEY

PROFESSIONAL PAPER 666 

PLATE 23

8= 60»= 1201=60"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval=Depth of burial.

K005

8= 901= 0° 1=60"

MAGNETIC NORTH

S=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 24

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X a

Grid interval = Death of burial

2C9

5=90° i=60° 1= 60°

MAGNETIC NORTH

Jj=Declination of polarization 

i=lnclinatior of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 25

8= 90'it 120*1= 60"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

M9DEL=4X6X J

Grid interval = Depth of burial

5=0" '=0° 1=75*

MAGNETIC NORTH;

8=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DBPABTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 26

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X j

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 27

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X .1

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination o* polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLAT?1 28

*63-

,5=30° i=0° 1=75° 8= 30° t= 20° 1= 75°

+-C5,

^06 > 

-03-

' = 30° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 29

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X j

Grid interval = Depth of burial MAGNETIC NORTH

Jj=Declination of polarization 

i=lnclination cf polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OP THE INTERIOR 

GEOLOGICAL SUBVEY

PROFESSIONAL PAPER 666 

^ 30

£=60° i=0° 1=75° 8= 60° i= 20° 1= 75'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6x J

Grid interval = Depth of burial

5=60° 1=45° 1= 75°

MAGNETIC NORTH

S= Declination of polarization 

t=lnclinaticn of polarization 

1= Inclination of earths fiplH
UNITED STATES DEPAKTMENT OF THE INTEKIOB 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 686 

PLATI1 31

8= 60° 1=75" 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OF THE INTEBIOE 

GEOLOGICAL STJBVEY

PBOFESSIONAL PAPEB 

PLATE 32

,S=90°i= 0° 1=75° 8=90° i=20° 1= 75°

5=90° i=30° 1=75° 6=90° i= 45° 1= 75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 33

8 = 90° i=120° 1= 75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X .1

Grid interval = Depth of burial

5=90° t=150° 1= 75'

MAGNETIC NORTH

5=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 4
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 34

TOTAL MAGNETIC INTENSITY, AT/J. fees)

MODEL=4X6X J

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination o' polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

I LATE 35

j= 0- i= 75° 1= 90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval=Depth of burial MAGNETIC NORTH

8= Dec'ination of polarization 

i=lncl;nation of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAP^.R 

PLATE 36

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X J

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=lnclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 37

8=30° i= 45° 1= 90° 8= 30° i= 60° 1= 90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 3!

8= 60" i=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.l

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 39

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 40

3=600 i=1500 I=90° 8= 90° i=0° 1=90°

8=90° t=20° 1=90°

4-.19J

8= 90° i= 30° t 90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination o' polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 41

<J= 90° i=45" 1=90° 6= 90'i = 60* 1= 90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 1

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPEH 

PLATE 42

6 = 90' i= 150* 1=90"

TOTAL MAGNETIC INTENSITY, AT/J. (cgs)

MODEL=4X6X j

Grid interval=Depth of burial.

j = Declination of polarization 

i = Inclination of polarization 

L Inclination of earths field

MAGNETIC NORTH
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

FTVA.TE 43

8= 0' i= 20* 1= 0*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial

M

4J)30

-K302

8=0° i=45c 1= 0°

MAGNETIC NORTH

8= Declination of polarization 

4=Inclination of polarization 

1= Inclination of earths ffeld
UNITED STATES DEPAKTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 44

= 0° i= 75° 1= 0°

6= 0° i= 90° 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= 0° i= 120°I= 0°

5= Declination of polarization 

t = Inclination of polarization 

1= Inclination of ea-ths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PL.ATE 45

8= 30° i=0° 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

g=: Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OF THE INTEKIOB 

GEOLOGICAL SURVEY

PBOFESSIONAL PAPEB 

PLATE 46

8= 30° 1=60- 1= 0-

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial

8=30* 1=120° 1=0°

MAGNETIC NORTH

8=Declination of polarization 

i =Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 47

OBI

L

4=30" (=150*1=0*

^q ?,4-i*8

6=60'i= 0* 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid intervals:Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i=lnclinrtion of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 48

S=60" i=45° 1=0° 4=60° i=60" 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i = Inclination of po'arization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 49

r

<5=60° 1=150° 1=0°

A +.157

X=90° i= 0° 1= 0°

(I

^+.22!' -,0§1

8=90° t=20° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X^5

Grid interval = Depth of burial. MAGNETIC NORTH

\

5=90° i=30° 1=0°

5=Declination of polarization 

»=Inclination o' polarization 

1= Inclination o' earths field

334-908 O - 69 - 5
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 50

5=90° i=60° 1=0"

8= 90° t=75° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X25

Grid interval = Depth of burial.

8=90° i=1200 1=0°

MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 51

7

267,

.+ 267,

5=90° i=1500 1=0° 8= 0° i=0* 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial

y

\

8=0° i=30' 1=30°

MAGNETIC NORTH

8= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTEBIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 52

8=0° i=60° 1=30°

5=0° t=90° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL, PAPEK 

PLATE 53

8=0° *= 120° 1=30'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X25

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination o* polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTEEIOE 

GEOLOGICAL SUEVEY

PEOFESSIONAL PAPEE 

PLATE 54

6= 30' i= 30° 1= 30° i=30° i=45° 1=30°

C i= 30° 1=60° 1=30° 

TOTAL MAGNETIC INTENSITY, AT/J, (cgs) 

Grid interval = Depth of burial MAGNETIC NORTH

6=Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 55

S= 30' i= 120° 1=30° 8= 30* i=l 50° 1=30*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

g=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATF 56

«= 60°'= 30" 1=30° 8=60° i=45* 1=30°

«=60° t= 60° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X25

Grid interval = Depth of burial MAGNETIC NORTH

i= Declination of polarization 

i= Inclination o' polarization 

1= Inclination o' earths field
UNITED STATES DEPAETMENT OF THE INTEEIOE 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 57

8= 60° i=i50« 1=30°

5 =90° i=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6X25

Grid interval = Depth of burial MAGNETIC NORTH

5= 90° i= 20° 1= 30°

6= Declinatior of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 58

TOTAL MAGNETIC INTENSITY, AT/J. (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

J=Declination of polarization 

t=Inclination o* polarization 

1= Inclination o* earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATF 59

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial

8= 90"i= 1501=30"

MAGNETIC NORTH

5=Declination of polarization 

1=Inclination o' polarization 

1= Inclination o' earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 60

5= 0" i= 45° 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAKTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 61

S= 0" t= 90° 1= 60° 5= 0° i= 120°I= 60"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

«=lnclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PKOFESSIONAL PAPEK 666 

PLATE 62

8= 30-1=30° 1=60'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

t= Inclination o* polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSION AT- PAPER 666 

PLATF 63

«= 30"i= 120°I= 60°

we-

+.4 JO

5 = 30° i= 150°I= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MOD£L=4X6X.25

Grid interval = Depth of burial, MAGNETIC NORTH

'r\

-(,0)9

5=60° i= 0° 1=60°

i= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 64

<5=60°t=20° 1=60° 5=600 i=30° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth ol burial MAGNETIC NORTH

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 65

8=60° i=1200 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial

5=90° i= 0° 1=60°

MAGNETIC NORTH

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 6
UNITED STATES DEPARTMENT OF THE INTEBIOH 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 66

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

4 = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT-" 67

5=90° i=75° 1=60° 8=90° t=120° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=8X6X .25

Grid intervals Depth of burial

8=0° i=0° 1=75°

MAGNETIC NORTH

;= Declination of polarization 

4= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 68

8=0' i=30' 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Death of burial MAGNETIC NORTH

6= Declination o* polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PL.ATE 69

5=0° i=90° 1=75"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

t = Inclination of polarization 

I=lnclinaton of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 70

8=30° i=20" 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT^ 71

8=30" t=75" 1=75"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 72

8=60° i=20° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

1=Inclination of polarization 

1= Inclination cf earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 73

5=60° t=75° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J t (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5 = Declination of polarization 

i = Inclination of polarization 

I=lnclinat'on of earths field
UNITED STATES DEPABTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 74

423

0-"

(5=90° t=Q° 1=75° J=90° t=20° 1=75°

252

8=90° '=30° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 75

3=90° t=60° 1=75' 6=90* i=75° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEI_=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAKTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 76

i. i i i

S=Q° 1=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 77

8=0° 1=75° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 7?

8= 30° i=0° 1=90°

8=30° t=20° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 79

S=30° i=45° 1=90° 8=30° i=60° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5= Declinatior of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 80

i=60° i=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination o* polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTEEIOE 

GEOLOGICAL SUEVEY

PEOFESSIONAL PAPEE 666 

PLATE 8'

5= 60°'=60° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X25

Grid interval = Depth of burial. MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 7
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 82

8=90" i=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.25

Grid interval = Depth of burial. MAGNETIC NORTH

8=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 83

8= 90° i=60° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination of'earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 

PLATE &»

5=90" (=150° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.25

Grid intervals Depth of burial

a = Declination of polarization 

i = Inclination of polarization 

I = lnclination of earths field

MAGNETIC NORTH
UNITED STATES DEPAKTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 85

+ 25

//

.5=0° i=0° 1=0° 6=0° i=20° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X'5

Grid interval = Depth of burial

5=0° (=45° 1=0°

MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE £«

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval^Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of errths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL. PAPER 666 

PLATE 87

S=0' i= 150° 1=0° 8=30° i=0° 1=0"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs) 

JV!ODEL=4X6X.5 

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination cf polarization 

(= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATT, 88

8=30° i=60° 1=0°

5 = 30° t= 75° 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (ces)

MODEL = 4X6X.5

Grid interval = Depth of burial

\

5=30° '=120° 1=0°

MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 89

TOTAL MAGNETIC INTENSITY, AT/J t (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 90

,5=60° i=45° 1=0° 8=60° t=60° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval=Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 91

-.09

S--60° i= 150* 1=0°

5^40)

4100-'

TOTAL MAGNETIC INTENSITY, AT/J

MODEL=4X6X5

Grid interval=Depth of burial

C (

400 -

* -.4*1)

+.522,

r

57

8:i90* t=20* 1=0-

(cgs)

MAGNETIC NORTH

100-

- .100

J=90''i=0' 1=0°

8=90° t=30" 1=0

8=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL FAPER 666 

PLATE 92

5=90° i=45" 1=0° 8=90° i=60° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X5

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 93

,5=90° 1=150" I=0'

-.1-

\

5= o° t=0° 1= 30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X-5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

I=z Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 666 

PLATE 9'

+J)10

<5=0' t=45* 1=30' 5=0° *=60° 1=30'

8=0- t=75* 1=30*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5=0* »=90* 1= 3P°

g= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATH 95

5=0° 1=150° 1=30°

\

+J01

5=30° i=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

+.10 )

5=30° '=20° 1=30°

5= Declination of polarization 

t = Inclination of polarization 

I -Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 96

\

3=30° 1=30° 1=30 5=30° '=45° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X5

Grid interval = Depth of burial MAGNETIC NORTH

{=Declination cf polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 97

-Mr

i= 120° 1=30° 8=30° i=150° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X5

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 8
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 98

i=30° 1=30' 8=60° 1=45* 1= 30°

TOTAL MAGNETIC INTENSITY, AT/J t (cgs)

MODEL=4X6X5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

(^Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 99

8=90° i=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X5

Grid interval = Depth of burial

*74'

MAGNETIC NORTH

\7

8= 90*'=20° 1=30°

+.043

8= Declination of polarization 

t= Inclination o' polarization 

1= Inclination o' earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 100

8=90' '=45° 1=30°

V

C 8=90° t= 60° 1=30° 

TOTAL MAGNETIC INTENSITY, AT/J, (cgs) 

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 101

8= 90°'=150° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X-5

Grid mterval = Depth of burial

5=0° i=20° 1=60°

MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 102

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLA E 103

«J=0' (=90* 1=60* 8=0* 1=120" 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X>5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declinatbn of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 104

5= 30'i=30* 1=60'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

g= Declination of polarization 

i = Inclination of polarization 

1= Inclination of eirths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 105

5=30° i=75° 1=60° i= 30" i= 120'!= 60'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

I=lnclinaticn of earths field
UNITED STATES DEPAKTMENT OP THE INTEKIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 176

S=60'i=30° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAKTMENT OP THE INTEKIOK 

GEOLOGICAL SURVEY

PKOPESSIONAL PAPER 

PLATE 107

8= 60° i= 120°I= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination cf earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATT 108

S= 90° t=2Q° l= 5=900 i=30° 1=60°

TOTAL MAGNETIC INTENSITY, &T/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 109

S= 90° i=75° 1=60' 8= 90° i= 120°I= 60°

5= 0° t= 0° 1= 75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

t=lnclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLAT-il 110

8= 0° '=30° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

J= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 111

8=0° i=90° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

<=lnclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER

PLATE 112

8= 30° i= 20° 1= 75°

+ 305

8=30° t=30' 1=75'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

(= Inclination of polarization 

1= Inclination of es rths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 113

8=30'i=750 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial

^3i!

:±£^

X=30° i=150° 1=75°

MAGNETIC NORTH

j= Declination o' polarization 

i= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 9
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT'1' 114

x\

K75I

5=60-4=0° 1=75' 5= 60°t= 20° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 115

8=60*1=75' 1=75*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 116

5= 90" i=20° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIORGEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 117

8= 90" i=; 75* 1=75'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval=Depth of burial

8=90" i=l 50° 1=75°

MAGNETIC NORTH

5 = Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 118

S=Q' t=cr 1=90* 8=0* i=20° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval=Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 119

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XJ5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 120

i= 0- »= 150°I= 90' 8= 30° i=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X5

Grid interval = Depth of burial MAGNETIC NORFH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLAT^ 121

3= 30° i=45° 1=90* 8= 30" i=60' 1=90°

TOTAL MAGNETIC INTENSITY, AT/J. (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 122

S= 30° '=150' 1=90° 8=60°'=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 123

<S=60" '=45° 1=90° 8= 60°'=60° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.s

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 124

i= 60* t=150* 1=90° 8=90*1=0* 1=90*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of po'arization 

t= Inclination of polarization 

1= Inclination of ear*hs field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 125

8= 90° i=60° 1=90*

TOTAL MAGNETIC INTENSITY, AT/J. (cgs)

MODEL=4X6X.5

Grid interval = Depth of burial MAGNETIC NORTH

5 = Declination of polarization 

1 = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 126

«= 90'i=l 50° 1=90*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X.5

Grid intervals Depth of burial

5 = Declination of polarization 

i ^Inclination of polarization 

I = Inclination of earths field

MAGNETIC NORTH
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 127

99

+0.40

8= 0° «=0° 1=0° 8= o* i=20* 1= 0°

S= 0° i= 30° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

-1,7

5=0° '=45° 1=0°

5= Declination o' polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 128

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X irj

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PL/TE 129

3= 0° '= 150°I=0° 6= 30° t=0° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X U3

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 10
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 66ft 

PLATE 110

= 30° i=60° 1=0°

5 =30° 1=75° 1=0°

TOTAL MAGNETIC, INTENSITY, AT/J, (cgs)

MODEL = 4X6X ^

Grid interval = Depth of burial

5=30° i=120°I= 0'

MAGNETIC NORTH

8= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAKTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 669 

PLATE 131

8=30° i=l 50° 1=0"

V

8= 60° t= 0° 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATP. 132

S=60° 4=45° 1=0° 6=60° i=60° 1=0°

-+.2

6 =60°'=75° 1= 0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

6=60° '= 120" 1=0°

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 133

\

5=60° '=150°!= 0° 6= 90° i= 0° 1= 0°

5 =90°'=20° 1=0° 5=90° '=30° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X if)

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPABTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT^ 134

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

M9DEL=4X6X .UO

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

1= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT-" 135

\

H750

-.4 

8=0* 1=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 1.0

Grid interval = Depth of burial MAGNETIC NORTH

i=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 136

3=0° i=45° 1=30° 8= 0° t=60° 1=30°

5=0° i=75° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 1.0

Grid interval = Depth of burial MAGNETIC NORTH

5=0° i=90° 1=30°

5= Declination of polarization 

1=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 137

8=0° '=120' 1=30° 8=0° t=150° 1=30

~2

«=30° '=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNEHC NORTH

64

8=30° i=20' 1=30°

8= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 138

4=30° «=30° 1=30' 8=30" '=45° 1=30°

*3<T i=6Q' 1=30'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 1^9

5=30° i=150° 1=30°

774

J=60° »=0° 1-30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X LO

Grid interval = Depth of burial MAGNETIC NORTH

6=60' t=20° 1=30°

5= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATO 140

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 141

S= 60° i= 120° 1=30°

*

5=90° i=0° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 1.0

Grid interval = Depth of burial MAGNETIC NORTH

5=90° i=20° 1=30°

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 142

V

6=90° i=30° 1=30° 8=90-1=45'' 1=30*

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X IX)

Grid interval = Depth of burial

-7( IB

8=90° t=75' 1=30°

MAGNETIC NORTH

8=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPEK 

PLATE 143

.-696'

6=90° i=120° 1=30° 8= 90° 1=150° 1=30'

;_U9

8= 0° i= 0° 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 1.0

Grid intervals Depth of burial MAGNETIC NORTH

8= 0° i= 20° 1= 60°

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 144

6= 0° i= 30" 1= 60° 8= 0° '= 45* 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xlfl

Grid interval = Depth of burial

+ 153

8=0° t=75' 1=60*

MAGNETIC NORTH

5= Declination o' polarization 

t=lnclination of polarization 

1= Inclination ol earths Held
UNITED STATES DEPARTMENT OF THE INTEBIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 145

6=0° i= 150° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X ID

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

< = Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 11
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 146

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X ifl

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t=lnclinatior of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PL^TE 147

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X uo

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 148

+ !.:&-

S= 60"'= 20° 1-60° 8= 60° l= 30° 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X 10

Grid interval = Depth of burial MW6NETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 149

S= 60° i= 75° 1= 60" 5= 60" 1=120" 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X 10

Grid interval = Depth of burial

8=90° »= 0° 1= 60°

MAGNETIC NORTH

J= Declination of polarization 

4=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 150

S- 90° i= 20° 1= 60° 8= 90° i= 30° 1= 60°

\

\

8= 90* '= 45° 1= 60°

TOTAL MAGNETIC INTENSITY, AT/J (cgs)

MODEL=4X6X 10

Grid interval=Depth of burial MAGNETIC NORTH

5=Declination of polarization 

t=Inclination of polarization 

I- Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 151

8=90° i=120c 1=60°

8=90°i=15Q°I= 60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X ix)

Grid interval = Depth of burial MAGNETIC NORTH

8=0° '=0° 1=75°

8=Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATF 152

450-

(5=0° i=20' 1=75° &= 0" t= 30° 1= 75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X LO

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 153

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X IX)

Grid interval = Depth of burial MAGNETIC NORTH

8=Declinatior of polarization 

i= Inclination of polarization 

1= Inclination of earths field'
UNITED STATES DEPARTMENT OF THE INTEBIOK 

GEOLOGICAL STJBVEY

PROFESSIONAL PAPER 666 

PLATE 154

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X ifl

Grid interval = Depth of burial MAGNETIC NORTH

j=Declinator of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 155

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X 1.0

Grid interval = Depth of burial MAGNETIC NORTH

6= Declaration of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 

PLATE 156

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X1X)

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 157

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6XU>

Grid interval = Depth of burial MAGNETIC NORTH

S= Declination of polarization 

t=Inclination o1 polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 158

+,4

S= 90° (.- 0" 1= 75° 8= 90"i= 20° 1= 75"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6XUO

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 159

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6X10

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

1 = Inclination of polarization 

1= Inclination of earths field'
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 160

-fc2

S= 0° i= 0° 1= 90° 8= 0° i= 20° 1= 90'

L + .6

8=0° i=30° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 10

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAETMENT OF THE INTEEIOE 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 161

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X LO

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field

334-908 0-69-12
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 162

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X UO

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATF 163

5= 30" '= 60° 1= 90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X U)

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOB 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 164

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6XU>

Grid interval = Depth of burial MAGNETIC NORT

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 166

S= 60° i=45° 1=90° 5= 60° i=60° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X10

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATF 166

5=60' i= 150"I= 90" g=90« t=0° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X l£l

Grid interval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATJI 167

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X ix)

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 168

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X1.0

Grid interval = Depth of burial MAGNETIC NORTH

g = Declination of polarization 

e = Inclination of polarization 

I=lnclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 169

5= 0° < = 20° 1= 0°

25Z-

+ 143

5=0° t=45° 1=0"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X=o

Grid interval = Depth of burial MAGNETIC NORTH

S=Declina*ion of polarization 

i=lnclinat'on of polarization 

1= Inclinat'on of earths field
UNITED STATES DEPAETMENT OF THE INTEEIOE 

GEOLOGICAL SUEVEY

PROFESSIONAL PAPEE 666 

PLATE 170

--247

- gniy

-206

,5=0° i=60" 1=0° 6=0" t=75° 1=0"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X<»

Grid interval = Depth of burial

- -1.78

+ 80-

+ L60-

+ 2.404

° 1=0°

MAGNETIC NORTH

5=Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT^ 171

<5=0° i=150° 1=0° 8= 30° i=0° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X«>

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

( Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATfi 172

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X=o

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 173

5= 60° i=0° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid mterval = Depth of burial MAGNETIC NORTH

6= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPAKTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 174

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 175

6= 60° t=150° 1= 0° 5=90-1=0° 1=0°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X°°

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=lnclinat:on of polarization 

I=lnclinat;on of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 176

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid mterval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 177

8=0° i=0° 1=30°

-+160

8=0° t=20° 1=30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X00

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 13
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 178

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i = Inclination cf polarization 

1= Inclination cf earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATF 179

S=0° i=1200 1=30°

+ 282 I I

I I S=0° 1=150° 1=30°

C 5 = 30°t=0° 1=30 

TOTAL MAGNETIC INTENSITY, AT/J, (cgs) 

Grid interval = Depth of burial

5=30° i=20° 1=30°

MAGNETIC NORTH

5=Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 180

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid interval = Depth of buria1 MAGNETIC NORTH

8=Declination of polarization 

4 = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 181

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

< = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 182

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X°°

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

t= inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 1S3

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X 00

Grid interval = Depth of burial MAGNETIC NORTH

g= Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 184

£=90° i=30° 1=30' 8= 90° i= 45° 1= 30°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X~

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination o4 polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 185

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X°°

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

(= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 186

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLAT'3 187

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6x°°

Grid interval = Depth of burial MAGNETIC NORTH

J=Declinaticn of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 

PLATE 188

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X <*,

Grid interval = Depth of burial MAGNETIC NORTH

8=Declination o* polarization 

t= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATT3 189

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6Xoo

Grid mterval = Depth of burial MAGNETIC NORTH

5=Declma*ion o1 polarization 

t=lnclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL TAPER 

PLATE 190

I (--

' f + 257

5=60° i=20° 1=60° 8=60° '=30° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«>

Grid mterval = Depth of burial

[£0=

X--360

8=60° t=60° 1=60°

MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLAT."? 191

8=60° i=l 20° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«,

Grid interval = Depth of burial MAGNETIC NORTH

g=Declinatbn of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

L= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATn 193

,5=90° i=75° 1=60' 8=90° 1=120° I- 60°

125

« = 90" i=150° 1=60°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«

Grid interval = Depth of burial MAGNETIC NORTH

-0.80

+0.80

5=0° i=0° 1=75°

6= Declination of polarization 

(^Inclination of polarization 

1= Inclination of earths field

334-908 0-69-14
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL, SURVEY

PROFESSIONAL PAPER 666 

PLATE 194

+ U3

5=0° t=20° 1=75° 8=0" c=30" T=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X«>

Grid mterval = Depth of burial

-+2*0

8=0° i=60° 1=75°

MAGNETIC NORTH

5 = Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLAT7, 195

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«°

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTEKIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 196

-23C

-08D

5=30'' '=0° 1=75°

-+2M

4 160-

-:j50

5=30° i=20° 1=75°

+acs

+ 2*0-

5=30° t=30° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6Xoo

Grid interval = Depth of burial MAGNETIC NORTH

5=Declination of polarization 

i = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 197

75T

.5=30° '=60° 1=75° 8= 30°'=75° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MpDEL = 4X6X°0

Grid interval = Depth of buriaJ MAGNETIC NORTH

8= Declination of polarization 

( = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 198

S=6W < = 0° 1= 75'

\

8=60° i=20° 1=75*

5=60° »= 30° 1= 75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X=o

Grid interval = Depth of burial MAGNETIC NORTH

\

-32

8=60° '=45* 1=75"

5= Declination of polarization 

t= Inclination o* polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATF. 199

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X»

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

i=Inclination of polarization 

J= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 200

-Z9

(5=90* '= 0° 1=75°

 

~

->S5

5= 90''= 20" 1=75°

*;

8 = 90" i=30° 1=75°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X«°

Grid interval = Depth of burial

5=90" i=45° 1=75

MAGNETIC NORTH

8=Declination of polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 201

00*

5=90' t=60° 1=75' 8=90° '=75° 1=75'

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X»

Grid interval = Depth of burial

J

5=90° '=150' 1=75°

MAGNETIC NORTH

5=Declinatioi of polarization 

i=lnclinatior of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 202

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X°°

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

1=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 203

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL=4X6X»

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

1=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 214

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL= 4X6Xo<,

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination ol polarization 

t=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTEBIOK 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 205

5=30° i=45° 1=90°

t38

8=30° '=60° 1=90°

=11:726

8=30' t=75 c I=903

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X~

Grid interval = Depth of burial

-t-JISO 

5=30" i=120 1=90

MAGNETIC NORTH

8= Declination of polarization 

i= Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 206

-+L50

f320

i5=30c t=15CT 1=90°

+!£<>-

^80--,

160

8=60 C 1=0° 1=90°

a=60 r t=20c 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X<»

Grid interval = Depth of burial

8=60' t=30" 1=90

MAGNETIC NORTH

5= Declination o' polarization 

i=Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OP THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATD 207

8=60 t= 60° I=90 C

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEI_=4X6X-»

Grid interval = Depth of burial MAGNETIC NORTH

5= Declination of polarization 

1 = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 

PLATE 208

5=60' '=150 1=90

H 224

8=90°'=0'

5 = 90° i=20' I=90 C

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«

Grid interval = Depth of burial MAGNETIC NORTH

8=90' '=30 C 1=90°

5= Declination of polarization 

t = Inclination of polarization 

1= Inclination of earths field
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 209

+3J3X

\\

-Q27

5=90° '=45° 1=90° 8= 90° i=60° 1=90"

+ 4D)

-QO

6=90° i= 75 C 1=90° 5=90° '=120° 1=90"

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«>

Grid interval = Depth of burial MAGNETIC NORTH

8= Declination of polarization 

i=Inclination of polarization 

1= Inclination of earths field

334-908 O - 69 - 15
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

PROFESSIONAL PAPER 666 

PLATE 210

1.6

~n

-.-450

+.80 

l= 150° 1=90°

TOTAL MAGNETIC INTENSITY, AT/J, (cgs)

MODEL = 4X6X«

Grid interval = Depth of burial

5 = Declination of polarization 

i = Inclination of polarization 

I = Inclination of earths field

MAGNETIC NORTH

U. S. GOVERNMENT PRINTING OFFICE : 1969 O - 334-908