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R90WR95W R94W R89WR91W R88WR93W R92W

R90WR91W R87WR92WR94WR95W R89W R88WR93W

T158N

T158NT160NT1

60N

T159N

T159NT162N

T161N

T162N

T161NT164NT1

64N

T163N

T163N

Columbus

Lignite

Portal

Flaxton

Bowbells

Powers Lake

Kenmare

9.9 / 11.0

12.2 / 18.011.4 / 13.0

8.0 / 18.5

6.6 / 10.5

12.6 / 3.0

7.3 / 16.5

3.8 / 14.0

16.7 / 5.5

11.5 / 12.0

5.2 / 4.0

12.2 / 13.5

9.3 / 10.0

15.1 / 11.5

9.8 / 17.5

11.3 / 13.0

10.1 / 13.5

14.0 / 14.0

12.2 / 4.5

19.5 / 8.0

13.3 / 8.5

12.8 / 10.5

10.7 / 16.0

14.0 / 11.58.7 / 2.0

14.4 / 14.0

7.2 / 4.0

12.6 / 3.0

10.6 / 11.0

13.1 / 15.0

9.4 / 12.0

9.4 / 17.0

8.2 / 13.0

8.6 / 18.0

6.8 / 10.5

15.8 / 10.5

11.6 / 13.5

9.5 / 12.5

13.4 / 12.5

£¤52

£¤52

£¤52

UV8

UV5

UV89

UV5

UV50

UV40

UV8

UV50

UV50

Renv

ille C

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Burk

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nty

Renv

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Ward

Cou

nty

Burk

e Cou

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Divid

e Cou

nty

Burk

e Cou

nty

Willia

ms C

ounty

Burke County

Mountrail County

Burke County

Ward County

Divide CountyWilliams County

Willia

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Moun

trail C

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y

Mountrail CountyWard County

North Dakota Geologica l SurveyGeologica l Investiga tion No 215 - Sheet 5 of 6 K2O Grades of the White Bear Member of the Prairie Formation

Cartogra phic Com pila tion: Navin T ha pa

Kenmare 100K Sheet, North Dakota

Edward C. Murphy, State GeologistLynn D. H elm s, Director Dept. of Minera l Resources

Ned W. Kruger2019

LegendThickness (ft)

0

1-3

4-6

7-9

10-12

13-15

16-18

19-21

Crain, E. R., 2014, Crain’s petrophysica l ha ndbook;U RL<http://spec2000.net/17-specpotash.htm >, accessed 14 Ja nuary 2014.Crain, E.R., and Anderson, W .B., 1966, Q ua ntitative log eva lua tion of theP ra irie Eva porite form a tion in Saskatchewa n: Journa l of Ca na dia n P etroleumT echnology, vol. 5, p. 145-152.Kruger, N.W ., 2014, T he Potash Mem bers of the Pra irie Form ation in NorthDa kota: North Da kota Geologica l Survey, Report of Investiga tion no. 113, 39p.Nelson, P.H ., 2007, Eva lua tion of potash gra de with ga m m a-ray logs: U .S.Geologica l Survey, O pen File Report 2007-1292, 14 p.

References:

Kenmare Quadrangle, North Dakota

-102°0'0"

-102°0'0"

-103°0'0"

-103°0'0"49°0'0" 49°0'0"

48°30'0" 48°30'0"

£¤2 Federa l H ighwaySta te H ighw ayUV50

CityOther Features

Symbols

Avg K2O % / Thickness (feet)!10.7/16.0

Well Control=

µ0 1 2 3 4

Miles

0 1 2 3 4Kilometers

Merca tor Projection Sta ndard P ara llel 48°30'0"N

North Am erica n 1983 Datum Centra l Meridia n 102°30'0"W

Sca le 1:100,000

T his series of m a ps of the Kenm are 100K Sheet was based on public data from 74 wells gathered by the North Dakota Industria l Com m ission – Departm ent of Minera l Resources, O il & Gas Division. T he W hite Bear Mem ber was identified on the geophysica l logs of 64 wells. Isopa ch contours were generated via PET RA (ver. 3.9.13) geologica l software. T he contour lines were com puter-generated based on well-control data only, with m inim a l a djustm ents m a de by the author. Areas with a geologica l a nom a ly m ay not be a ccurately portrayed. T he potash m em ber thickness for ea ch well, and the isopa ch contours generated from them , were m odified from Kruger (2014). All ca lcula tions were based on ga m m a -ray log m ea surem ents recorded in API units ta ken at six-inch increm ents throughout the potash-conta ining portion of the log. Corrections for borehole size and drilling m ud weight as well as rem ova l of the baseline ga m m a -ray signa l were m a de (Crain, 2014) (Crain & Anderson, 1966). T he corrected ga m m a -ray m easurem ents were converted into apparent potassium oxide (K2O ) concentrations. Avera ge K2O concentrations and potash m em ber thicknesses were obta ined using the gra de-thickness m ethod described in Nelson (2007), where bed thickness is equa l to the dista nce between the elevations at which the ga m m a -ray response declines to one-ha lf its m a xim um va lue. W hen a potash m em ber displayed m ultiple ga m m a -ray log pea ks separated by troughs representing sa lt or insolubles such as clay or anhydrite, thin potash interva ls at the upper or lower boundaries of the m em ber were not included in thickness or avera ge-potash-gra de ca lcula tions if the corrected ga m m a -ray m easurem ents were less tha n 100 API or separated by m ore tha n four feet from m a in body of the potash m em ber. T his occurred m ost frequently in deposits of the W hite Bear Mem ber, which m ay appear as one or two potash-rich beds underlying a thin potash-conta ining zone separated by an interbed of ha lite. T he volum e of potash from the W hite Bear Mem ber represented by this sheet is approxim a tely 11,800,000 acre feet.