U.S. DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY

PRELIMINARY REPORT ON MAJOR AND MINOR ELEMENTSIN CORES FROM THE TRIASSIC SHUBLIK FORMATION,

JURASSIC AND CRETACEOUS KINGAK SHALE, AND CRETACEOUSPEBBLE SHALE UNIT, HUE SHALE, AND TOROK FORMATION,

NORTH SLOPE, ALASKA

by

Caroline M. Isaacs1 Kenneth J. Bird1

Marjorie Medrano1Margaret A. Keller1

David Z. Piper1Donald L. Gautier2

Open-File Report 95-236

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

1 U.S. Geological Survey 2 U.S. Geological Survey345 Middlefield Road, MS 999 Box 25046 - MS 960Menlo Park, California 94025 Denver, Colorado 80225

1995

CONTENTS

Introduction..........................................................................................................................!Regional Stratigraphy and Sample Selection........................................................................!Sample Preparation............................................................................................................. 2Analytical Methods and Reproducibility...............................................................................2Data Tables...........................................................................................................................7Acknowledgments................................................................................................................?References..........................................................................................................................29

FIGURES

1. Index map of sampled wells..........................................................................................32. Generalized geologic map of the North Slope ...............................................................33. Structural and stratigraphic cross section across the North Slope..................................44. Chronostratigraphic chart across the North Slope..........................................................55. Sedimentary facies map of the Shublik Formation........................................................6

TABLES

1. Sample identification.....................................................................................................82. Techniques and detection limits for analyzed elements..................................................93. Analytical reproducibility of duplicate analyses........................................................... 114. Relative standard deviations of duplicate analyses ......................................................195. Abundances of major and minor elements in analyzed samples .................................21

INTRODUCTION

This report provides preliminary inorganic geochemical data for a set of 33 core

samples from 8 wells in the North Slope of Alaska (Table 1, Figure 1). These samples were analyzed as a reconnaissance study of the distribution of trace elements in petroleum

source-rocks and shales in the region. Formations sampled include the Triassic Shublik Formation, Jurassic and Cretaceous Kingak Shale, and Cretaceous pebble shale unit, Hue Shale, and Torok Formation. These analyses supplement and expand on earlier inorganic geochemical analyses by Brosge and Tailleur (1988). Organic geochemical analyses and

thermal maturity measurements for most of the wells analyzed in this study may be found in the reports by Magoon and Bird (1988), Claypool and Magoon (1988), Magoon and others (1988), and Bayliss and Magoon (1988).

REGIONAL STRATIGRAPHY AND SAMPLE SELECTION

The North Slope of Alaska is a foreland basin formed in Mesozoic and Cenozoic time in response to crustal loading by the Brooks Range, an erogenic belt produced by collision of the continental Arctic Alaska plate with an island arc (Figure 2). The foreland basin developed on an older passive margin sequence composed of Mississippian to Cretaceous clastic and carbonate rocks. A schematic cross section (Figure 3) shows the characteristic structural and stratigraphical relations. The stratigraphic nomenclature and ages of these rocks are summarized in figure 4. The paleogeography during formation of the passive margin consisted of a land mass to the north and the open ocean to the south in

present-day coordinates. Land and sea relations were reversed during foreland basin development with the erogenic ancestral Brooks Range highlands in the south and the marine basin to the north. Marine shale having the requisite organic carbon richness and type to be classified as petroleum source rocks have been identified in previous studies as occurring in both passive margin rocks (Triassic Shublik Formation, Jurassic and

Cretaceous Kingak Shale, and Cretaceous pebble shale unit) and foreland basin rocks (Hue Shale and Torok Formation).

Regional reconstruction indicates that during deposition of the Shublik Formation, the Kingak Shale, and, to some extent, the pebble shale unit sedimentary fades were oriented in a west-northwest to east-southeast trend, with the shoreline to the north of the modern coastline. Figure 5 summarizes the paleogeography and sedimentary facies for the Shublik

Formation. In contrast to these passive margin facies trends, regional reconstructions show

that foreland basin trends were distinctly different. Lithofacies and seismic reflection data show that the foreland basin was filled primarily from southwest to northeast The Hue Shale (previously reported as the gamma-ray zone of the pebble shale unit by Bird, 1988) is interpreted as the most distal, most slowly deposited, and probably the deepest marine of the foreland basin deposits. The overlying Torok Formation is interpreted as a less distal and more rapidly deposited unit composed of marine shale and turbidite sandstone.

Average organic carbon abundance in the Shublik Formation increases with increasing distance from the paleoshoreline, from a mean of about 1% in the Drew Point No. 1 well to a mean of about 3% in the Inigok No. 1 well (Magoon and Bird, 1987, 1988). Organic carbon abundance follows a similar pattern in the Kingak Shale, increasing from a mean of about 1% in the Drew Point No. 1 well to about 2% in the Inigok No. 1 well and about 3%

in the Seabee No. 1 well (Magoon and Bird, 1987,1988). The samples reported here were selected to represent, insofar as possible, a transect more or less perpendicular to the paleogeographic shoreline trend of the passive margin fades.

SAMPLE PREPARATION

Samples were selected from cores stored at U.S. Geological Survey repositories in Menlo Park, California (Table 1). From a piece of core weighing several hundred grams, two matching subsamples of 10-20 g were cut with a free-flowing water saw for (1) major and minor element chemistry, and (2) organic carbon analysis (not reported here). The remainder of each sample piece was retained for subsequent petrographic and other petrologic studies.

ANALYTICAL METHODS AND REPRODUCffilLITY

The samples were analyzed by a multi-extraction, multi-element major and trace element package (ME3) by XRAL Laboratories in Don Mills, Ontario, Canada. Techniques included X-ray fluorescence spectrometry (XRF), instrumental neutron activation analysis (NAA), and inductively coupled plasma spectrometry (ICP). The 33

North Slope samples were analyzed as a part of one batch, consisting of a total of 60 samples, including 8 duplicate analyses of samples and 2 duplicate analyses of system standards. For each element, the technique used and detection limit is given in Table 2.

160° 155° 150°

71

70°

69°

Point Barrow

0> East Barrow No. 19

East Simpson No. 2Drew Point No. 1

North ^ Kalikpik

Figure 1. Index map of part of the North Slope of Alaska showing locations of wells sampled.

156' 148* 140'

Cretaceous and Tertiary rocks (Brookian sequence)

. Misslssippian ID LowerI Cretaceous rocks' (EUesmerian sequence)

]Pre-Mississippian rocks ] (basement for petroteum)

^ Ql and/or gas field

S Oil seep

\ Gasseep '

i . Thrust fault

Figure 2. Generalized geologic map of the North Slope, showing locations of oil and gas fields, hydrocarbon seepages, major tectonic elements, and cross section (Rgure 3). Modified from Bird (1991) and Bird and Molenaar (1992).

BROOKS RANGE

SOUTH

FOOTHILLS COASTAL PLAIN SHELF , SLOPF.

NORTHColville Group

5000 -

10.000 -

15,000 -

20.000 -

25.000 -

30.000 -

Thrust repetitions of Lisburne Group

and Otuk Formation

FIGURE 3. Schematic structural and stratigraphic cross section across the central North Slope (from Bird, 1987). Shaded zone between Torok Formation and Kingak Shale is the pebble shale unit and gamma-ray zone. See Figure 2 for location of section.

Ma

s swAllochthonous and I Umiat area

parautochthonous AutochthonousKuparuk

River area

NEPrudhoe Point

Bay Thomson

97.5-

.-. .. .- . .. 7*T\«. rt:. '.:. .'

320

360-

PERM.

PENN.

MISS.

1. Local usage; laterally equivalent to Kemik Ss.2. Carman and Hardwick (1983)3. Complex relations are probably due to

juxtaposition of different allochthons

4. Fire Creek Siltstone Member of Ivishak Formation5. Rocks called Ivishak Ss. at Prudhoe Bay by Jones and Speers (1976)6. Mull and others (1982)7. As shown, includes Itkilyariak Fm. in northern part of basin

EXPLANATION OF LITHOFACIES

Shallow marine and nonmarine deposits

Shallow marine or shelf sandstone

Marine shale and mudstone

I I

Condensed shale section

Limestone

Dolomite

Turbiditic sandstone

Conglomerate

Figure 4. Chronostratigraphic chart of post-Devonian rocks across the North Slope basin. Heavy dotted line at top of pebble shale unit and extending down section into the Jurassic in allochthonous rocks separates Brookian sequence (foreland basin) rocks above from Ellesmerian sequence rocks (passive margin) below. Absolute time scale modified from Palmer (1983). Vertical time scale changes by a factor of 2 at 144 Ma.

71'

70°

69°

68"

67°

165* 162° 159* 156° 153° 150" 147° 144°

w& Northern onlaptmitotStiubfk Formation and

Sag River Sandstone, undividedSouthern Imit of truncation of

Shubtk Formation and Sag KverSandtone, undivided, byEarly Cretaceous erosion

CANADA BASIN

Approximate northern limit of raOiolarian chert

50 100 150 Mites

50 100 150 200 Kilometers

i| Outcrop of lower Eiiesmerian |j sequence (undivided)

Facies boundary

EXPLANATION

Thrust fault bounding northern limit of Endicott and De Long Mountains subterranes Approximately located

Deformation front of the Romanzof and Tigara uplifts

Isopach Showing thickness of Shubiik Formation and Sag River Sandstone, undivided, in meters

Sedimentary facies of Shublik Formation

Near-shore facies

Organic-rich facies

^3 Organic-rich mudstone and limestone facies

Starved-basin facies

Figure 5. Facies distribution of the Shublik Formation and isopachs for the undivided Shublik Formation and Sag River Sandstone. From Moore and others (1992) based on summaries of Parrish (1987) and Hubbard and others (1987).

6

Methods and reproducibility of previously reported NAA analyses are detailed by Isaacs (1992), and reproducibility of XRF and ICP analyses by Piper and Isaacs (1995, in press). For previously reported samples analyzed using both NAA and ICP methods at

XRAL Laboratories, common elements (Fe, Ca, Na, Co, Cr, Mo, Sc, and Zn) agreed better than ± 3% at one standard deviation. Intermethod comparison with XRF results at XRAL Laboratories and interlaboratory comparison of XRF and ICP results for the same samples at U.S. Geological Survey laboratories also showed excellent agreement for all elements except Ba. For Ba, different analytical methods (and for ICP, different chemical

digestion procedures) yield significantly different results, probably because of incomplete

extraction of Ba during chemical digestion (Piper and Isaacs, 1995, in press).For the batch including the 33 North Slope samples reported here, duplicate analyses

and a system standard duplicate analysis are given in Table 3. Relative standard deviations, grouped by abundance class, are shown in Table 4. For all major oxides and LOI, relative standard deviations are in the range 0.0-1.2%. For minor elements, relative standard deviations are in the range 0.0-3.2% for abundances greater than 100 times the detection limit, and 0.4 6% for abundances 10-100 times the detection limit. Only a few elements with mean abundances

Table 1. Well identifications, sample depths, and stratigraphic units of core samples analyzed from the North Slope of Alaska.

WELL

Seabee No. 1

Inigok No. 1

North Inigok No. 1

North Kalikpik No. 1

Ikpikpuk No. 1

Drew Point No. 1

East Simpson No. 2

South Barrow No. 19

API Number

50-287-20007

50-279-20003

50-103-20017

50-103-20011

50-279-20004

50-279-20002

50-279-20007

50-023-20012

Sample Depth (ft)

14589 14593.8 14599 14604 8849.5-51.5 8849.59457.5

10299 12273.512275.510160 10165.37131.4 71367148.57149.57369 7372.373767491 7500

1027710283102886927 6941 75447568.56344.3 6354636713541359.3

Stratigraphic Unit

Kingak Shale Kingak Shale Kingak Shale Kingak Shale Torok Formation Torok FormationKingak Shale Kingak Shale Shublik FormationShublik FormationShublik Formation Shublik FormationPebble shale unit Pebble shale unitPebble shale unitPebble shale unitHue Shale Hue ShaleHue ShaleKingak Shale Kingak Shale Shublik FormationShublik FormationShublik FormationKingak Shale Kingak Shale Shublik Formation.Shublik FormationHue Shale Hue ShaleHue ShaleHue Shale/Torok FormationHue Shale/Torok Formation

Table 2. Methods of analysis and detection limits. Methods are X-ray fluorescence spectrometry (XRF), inductively coupled plasma spectrometry (ICP), and neutron activation analysis (NAA).

Oxide or element

Si02A1203Fe2O3MgOCaO

Na2OK20Ti02P205MnOLOIAgAsAuBBaBeBrCdCeCoCrCsCuEuGeHfL-

Method

XRFXRFXRFXRFXRFXRFXRFXRFXRFXRFXRFICP

NAANAAICPXRFICP

NAAICP

NAANAANAANAAICP

NAAICP

NAANAA

Detection limit

0.01%0.01%0.01%0.01%0.01%0.01%0.01%0.01%0.01%0.01%0.01%0.1 ppm1 ppm2 PPb

10 ppm10 ppm

1 ppm0.5 ppm1 ppm1 ppm0.5 ppm0.5 ppm0.5 ppm0.5 ppm0.05 ppm

10 ppm0.2 ppm5ppb

Table 2. continued

Oxide or element

LaLuMoNbNdNiPbRbSbScSeSmSrTaTbThUVWYYbZnZr

Method

NAANAANAAXRFNAAICPICPXRFNAANAANAANAAXRFNAANAANAANAAICP

NAAXRFNAAICPXRF

Detection limit

0.1 ppm0.01 ppm2 ppm

10 ppm3 ppm1 ppm2 ppm

10 ppm0.1 ppm0.01 ppm1 ppm0.01 ppm

10 ppm0.5 ppm0.1 ppm0.2 ppm0.1 ppm2 ppm1 ppm

10 ppm0.05 ppm0.5 ppm

10 ppm

10

Table 3. Duplicate analyses of rocks and standards analyzed in the same batch with samples from the North Slope of Alaska reported here. The system standard is not included in sample averages.

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10, 165.3Run 1Run 2

IkpikpukNo. 1 7,369Run 1Run 2

East Simpson No. 2 6,344.3Run 1Run 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)Run 1Run 2

Other sample #2 (TBP10613-435)Run 1Run 2

Other sample #3 (TBB 26001-1 1)Run 1Run 2

Other sample #4 (TBB 26022-1)Run 1Run 2

System Standard (Sy-2)RunlRun 2

SiO2(%)

55.255.2

49.449.3

--~

60.160.2

38.138.0

~

60.159.6

A1203 (%)

16.116.1

18.518.5

18.518.7

~~

9.859.84

~

~

11.911.9

Fe2O3 (%)

8.218.24

10.510.4

4.134.11

4.654.64

~

6.216.22

MgO(%)

1.701.69

1.751.75

1.801.79

~

2.402.38

2.692.70

CaO(%)

1.041.05

0.590.60

~

0.540.55

17.417.4

7.997.95

Na2O(%)

0.630.70

~

0.710.73

~

0.900.91

2.722.74

4.194.19

K20(%)

2.392.40

--

2.832.85

3.453.46

~

1.711.72

~

4.324.32

Sample averages

Number (N) Standard deviation Relative std. dev.

SiO2(%)4 0.04 0.1%

A12O3(%)4 0.03 0.2%

Fe2O3(%)4 0.02 0.3%

MgO(%)

4 0.005 0.3%

CaO(%)

4 0.004 0.1%

Na2O (%)4 0.021.2%

K2O(%)4 0.006 0.2%

11

Table 3. continued

Sample ID

SeabeeNo.l 14,599RunlRun 2

North Inigok No. 1 10,165.3Run 1Run 2

Ikpikpuk No. 1 7,369Run 1Run 2

East Simpson No. 2 6,344.3Run 1Run 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)Run 1Run 2

Other sample #2 (TBP 106 13-435)RunlRun 2

Other sample #3 (TBB 26001-1 1)Run 1Run 2

Other sample #4 (TBB 26022-1)Run 1Run 2

System Standard (Sy-2)Run 1Run 2

TiO2(%)

0.9140.910

0.9350.926

~

0.9050.915

0.5100.531

~

~

0.1430.139

P205(%)

0.160.16

~

0.120.12

~

0.190.19

~~

0.390.39

~

~~

0.430.43

MnO(%)

0.080.08

~

0.020.02

0.020.02

~

0.040.04

0.320.32

LOI(%)

13.813.8

15.115.1

9.659.60

22.522.6

1.201.20

Ag (ppm)

1.61.6

0.90.9

Table 3. continued

Sample ID

SeabeeNo.1 14,599RunlRun 2

North Inigok No. 1 10, 165.3Run 1Run 2

Ikpikpuk No. 17369Run 1Run 2

East Simpson No. 2 6,344.3Run 1Run 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)Run 1Run 2

Other sample #2 (TBP10613-435)Run 1Run 2

Other sample #3 (TBB 26001-11)RunlRun 2

Other sample #4 (TBB 26022-1)Run 1Run 2

System Standard (Sy-2)Run 1Run 2

B(ppm)

130135

190205

182198

8695

114120

91103

Ba(ppm)

414425

765745

700711

13501360

446425

Be(ppm)

22

24

55

Table 3. continued

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10,165.3RunlRun 2

Ikpikpuk No. 1 7,369Run 1Run 2

East Simpson No. 2 6,344.3Run 1Run 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)RunlRun 2

Other sample #2 (TBP10613-435)RunlRun 2

Other sample #3 (TBB 26001-11)RunlRun 2

Other sample #4 (TBB 26022-1)RunlRun 2

System Standard (Sy-2)Run 1Run 2

Cr(ppm)

200210

120120

...

5652

Cs(ppm)

5.55.8

9.59.6

4.64.1

Cu (ppm)

82.979.0

62.162.4

128136

54.451.9

57.454.8

4.03.8

Eu (ppm)

0.550.65

1.731.63

0.660.65

Ge(ppm)

Table 3. continued

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10,165.3Run 1Run 2

IkpikpukNo. 1 7,369Run 1Run 2

East Simpson No. 2 6,344.3RunlRun 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)RunlRun 2

Other sample #2 (TBP10613-435)Run 1Run 2

Other sample #3 (TBB 26001-1 1)RunlRun 2

Other sample #4 (TBB 26022-1)Run 1Run 2

System Standard (Sy-2)RunlRun 2

La (ppm)

19.019.2

45.745.5

14.915.0

Lu (ppm)

0.330.34

0.460.46

0.240.24

Mo (ppm)

6770

1618

Table 3. continued

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10, 165.3Run 1Run 2

IkpikpukNo. 1 7,369Run 1Run 2

East Simpson No. 2 6,344.3Run 1Run 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)Run 1Run 2

Other sample #2 (TBP1061 3-435)Run 1Run 2

Other sample #3 (TBB 26001-1 1)Run 1Run 2

Other sample #4 (TBB 26022-1)Run 1Run 2

System Standard (Sy-2)Run 1Run 2

Rb (ppm)

9293

114108

151157

5456

214211

Sb (ppm)

4.34.5

2.72.7

1.61.3

Sc (ppm)

9.229.46

18.718.1

6.686.68

Se (ppm)

2829

1516

88

Sm (ppm)

2.502.54

7.207.22

2.422.43

Sr (ppm)

186190

157159

218221

689687

263266

Ta (ppm)

Table 3. continued

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10,165.3Run 1Run 2

IkpikpukNo. 1 7,369RunlRun 2

East Simpson No. 2 6,344.3RunlRun 2

East Simpson No. 2 6,354Run 1Run 2

Other sample #1 (TBP10613-55)Run 1Run 2

Other sample #2 (TBP10613-435)Run 1Run 2

Other sample #3 (TBB 26001-1 1)Run 1Run 2

Other sample #4 (TBB 26022-1)RunlRun 2

System Standard (Sy-2)Run 1Run 2

Tb (ppm)

0.30.3

0.90.8

0.30.3

Th (ppm)

7.67.9

13.013.0

4.23.9

U(ppm)

5.25.4

5.45.2

2.62.9

V (ppm)

489430

302310

163167

7172

5757

4947

W(ppm)

21

23

Table 3. continued

Sample ID

SeabeeNo.l 14,599Run 1Run 2

North Inigok No. 1 10,165.3 Run 1Run 2

Ikpikpuk No. 1 7369 Run 1Run 2

East Simpson No. 2 6,344.3 Run 1Run 2

East Simpson No. 2 6,354 Run 1Run 2

Other sample #1 (TBP10613-55) RunlRun 2

Other sample #2 (TBP10613-435) Run 1Run 2

Other sample #3 (TBB 26001-1 1) Run 1Run 2

Other sample #4 (TBB 26022-1) Run 1Run 2

System Standard (Sy-2) RunlRun 2

Zn (ppm)

745694

213216

179215

117112

124121

240241

Zr(ppm)

240238

181179

181181

108105

284287

Sample averages

Number (N) Standard deviation Relative std. dev.

Zn (ppm)5 9.53.2%

Zr(ppm)4 0.9 0.5%

18

Table 4. Relative standard deviations for duplicate analyses, grouped by mean abundance relative to the detection limit for each element For CaO and Br, standard deviations for single samples with specially high abundances are listed separately. Data are detailed in TableS.

Element

Si02A12O3Fe2O3MgOCaO

Na2OK2OTiO2P205MnOLOIAgAsAuBBaBeBrCdCeCoCrCsCuEuHfLaLuMoNbNd

1-10X

0.0%

10%

1.5%

10-100X

0.7%

0.7%0.0%

5.3%1.6%4.2%2.7%0.8%

3.4%2.8%1.0%5.8%

2.3%

3.6%1.4%

0.5%1.6%

0.7%

100-1, OOOX

0.3%0.3%0.0%1.2%0.2%

0.0%

1.8%

1.7%

0.3%

1,000-10,OOOX

0.07%0.2%

0.1%

19

Table 4. continued

Element

NiPbRbSbScSeSmSrTaTbThUVwYYbZnZr

1-10X

17%

5.3%3.4%

18%4.7%

10-100X

2.0%

1.8%2.9%

1.9%

0.4%

1.2%2.6%

0.4%

0.5%

100-1,OOOX

1.2%

0.3%

3.2%

3.2%

1,000- 10,OOOX

20

Table 5. Abundances of major and minor elements for samples analyzed from the North Slope of Alaska.

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. InigokNo. 1 1016010165.3

No.KalikpikNo. 1 7131.471367148.57149.5

DcpikpukNo. 1 73697372.3737674917500 .102771028310288

Drew Point No. 1 6927694175447568.5

E. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

SiO2(%)

56.852.255.255.850.551.963.572.653.144.533.847.257.455.967.464.449.454.055.262.363.624.920.520.156.360.464.479.561.860.155.944.337.6

A12O3 (%)

18.519.316.117.220.620.315.910.814.310.57.34

10.320.520.313.515.518.520.418.916.716.24.434.204.12

18.720.3

9.964.81

17.118.518.113.914.3

Fe203 (%)

5.015.318.216.668.158.385.323.694.983.482.424.864.525.264.694.50

10.57.347.204.694.461.592.061.298.034.023.612.324.894.136.568.82

11.1

MgO(%)

1.241.091.701.502.472.431.211.801.202.111.751.851.841.971.291.401.751.791.931.361.301.451.821.071.911.701.301.252.061.802.071.511.59

CaO(%)

0.80

0.941.041.141.051.080.592.178.66

17.927.716.2

1.260.941.801.590.590.600.620.800.74

34.536.438.30.990.657.864.930.930.540.811.420.79

Na2O (%)

0.74

0.780.630.671.331.610.660.780.450.520.390.550.850.800.490.530.710.860.820.700.670.500.430.500.590.570.480.221.060.901.121.291.10

K2O(%)

2.52

2.752.392.544.284.302.592.182.832.151.211.703.533.552.192.582.833.393.112.682.490.690.640.673.223.682.090.863.183.453.342.332.47

21

Table 5. continued.

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. Inigok No. 1 1016010165.3

No. Kalikpik No. 1 7131.471367148.57149.5

IkpikpukNo. 1 73697372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

Ti02(%)

1.00

1.030.9140.9341.041.020.9400.7250.7220.5650.4090.6300.8820.9130.8600.9420.9350.9630.9321.010.9610.2510.2190.2311.041.190.6860.4340.7610.9050.8550.7770.750

P205(%)

0.17

0.150.160.150.210.210.180.170.090.104.160.090.150.120.190.220.120.200.120.210.175.655.192.910.160.120.891.430.180.190.150.360.26

MnO(%)

0.05

0.030.080.060.050.060.030.02

Table 5. continued

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. Inigok No. 1 1016010165.3

No. Kalikpik No. 1 7131.471367148.57149.5

DqrikpukNo. 1 73697372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

B (ppm)

190

1911791781931831701321941378713023222715418719024122419018161594924725718499182205188142155

Ba (ppm)

401

59741442992189550436412201160134090610501120701790765824861549566455867487935898408293742700747684636

Be (ppm)

2

224432111

Table 5. continued

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. Inigok No. 1 1016010165.3

No. Kalikpik No. 1 7131.471367148.57149.5

IkpikpukNo. 1 73697372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

Cr(ppm)

110

11010010012012088741401501602001001109096120120100969411011014012013013088981201208488

Cs(ppm)

7.8

9.57.47.2

14.112.87.55.97.15.94.75.511.411.48.3

10.59.511.210.37.67.42.32.42.18.97.616.84.9

13.111.913.56.19.0

Cu (ppm)

21.6

34.719.921.555.447.120.215.773.492.255.982.937.134.418.319.762.152.444.416.415.953.737.978.437.347.924.26.7

12811580.965.083.0

Eu (ppm)

1.33

1.131.191.261.491.291.301.010.940.581.360.551.601.581.001.011.732.461.841.291.182.110.991.661.601.341.671.671.841.981.481.821.35

Ge(ppm)

Table 5. continued

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. InigokNo. 1 1016010165.3

No. Kalikpik No. 1 7131.471367148.57149.5

Dqnkpuk No. 1 73697372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

La (ppm)

50.0

46.947.947.249.047.845.832.931.025.636.219.054.355.433.737.945.756.152.256.252.056.324.333.752.956.644.538.796.352.539.736.134.6

Lu (ppm)

0.46

0.370.430.440.490.490.400.430.330.310.640.330.450.500.410.460.460.500.490.450.430.880.440.460.570.510.510.530.550.530.420.490.42

Mo(ppm)

Table 5. continued

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. Inigok No. 1 1016010165.3

No.KalikpikNo. 1 7131.471367148.57149.5

IkpikpukNo. 1 73697372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

Rb(ppm)

114

12292

10016616410886

1169072

107157157106127114143137114110433432

12512310637

14115114699

104

Sb(ppm)

0.6

1.80.40.52.02.00.60.62.21.32.24.31.01.80.70.82.72.71.30.50.43.11.32.11.91.90.90.41.31.13.83.02.6

Sc (ppm)

13.5

11.315.014.921.519.812.310.014.812.29.919.22

18.518.611.113.018.721.319.212.912.010.27.119.53

20.717.011.77.46

19.122.121.716.517.2

Se (ppm)

Table 5. continued

Well Depth (ft)

Seabee No. 1 1458914593.81459914604

InigokNo. 1 8849.5-51.58849.59457.51029912273.512275.5

No. Inigok No. 1 1016010165.3

No.KalikpikNo. 1 7131.471367148.5

7149.5IkpikpukNo. 1 7369

7372.3737674917500102771028310288

Drew Point No. 1 6927694175447568.5

Ea. Simpson No. 2 6344.363546367

So. Barrow No. 19 13541359.3

Tb (ppm)

0.7

0.50.80.70.80.60.70.60.60.30.70.30.90.90.60.60.91.21.00.80.71.6

0.61.10.90.61.01.01.01.10.81.10.6

Th (ppm)

12

1212121413119.99.07.36.47.6

16149.6

1113161413134.23.13.8

1415119.5

1613128.59.2

U (ppm)

3.1

3.03.72.94.73.73.22.66.66.0

22.85.24.44.7

3.43.55.46.04.54.03.5

34.313.326.54.04.84.53.59.95.5

11.217.315.1

V (ppm)

154

13213614026122711994

28321020448927032713616630233621113812923774

18621619510868

163290430295492

W (ppm)

Table 5. continued

Well

Seabee No. 1

Inigok No. 1

No. Inigok No. 1

No. Kalikpik No. 1

IkpikpukNo. 1

Drew Point No. 1

Ea. Simpson No. 2

So. Barrow No. 19

Depth (ft)

1458914593.814599146048849.5-51.58849.59457.51029912273.512275.51016010165.37131.471367148.57149.573697372.37376749175001027710283102886927694175447568.56344.36354636713541359.3

Zn (ppm) Zr (ppm)

93.0 229

109 19592.0 240107 230114 182106 18686.1 27366.9 335125 14299.0 142275 138745 160170 17993.2 186111 289109 258213 181142 174135 21096.8 27790.6 293110 97118 69223 9088.6 201202 242127 27048.7 431179 259113 181364 161178 161294 142

28

JCES

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Bird, K.J., 1987, The framework geology of the North Slope of Alaska as related to oil- source rock correlations, in Tailleur, I., and Weimer, P., eds., Alaskan North Slope Geology: Pacific Section Society of Economic Paleontologists and Mineralogists Book 50, v.l, p. 121-143.

Bird, K.J., 1988, Alaskan North Slope stratigraphic nomenclature and data summary for government-drilled wells, in Gryc, G., ed., Geology and exploration of the National Petroleum Reserve in Alaska, 1974 to 1982: U.S. Geological Survey Professional Paper 1399, p. 317-353.

Bird, K.J., 1991, Geology, play descriptions, and petroleum resources of the Alaskan North Slope (petroleum provinces 58-60): U.S. Geological Survey Open-File Report 88- 450Y, 52 p.

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Carman, G.J., and Hardwick, P., 1983, Geology and regional setting of the Kuparuk oil field, Alaska: American Association of Petroleum Geologists Bulletin, V. 67, p. 1014- 1031.

Claypool, G.E., and Magoon, L.B., 1988, Oil and gas source rocks in the National Petroleum Reserve in Alaska, in Gryc, G., ed., Geology and Exploration of the National Petroleum Reserve in Alaska, 1974 to 1982: U.S. Geological Survey Professional Paper 1399, p. 451-481.

Hubbard, R.J., Edrich, S.P., and Rattey, R.P., 1987, Geologic evolution and hydrocarbon habitat of the 'Arctic Alaska microplate 1 , in Tailleur, I., and Weimer, Paul, eds., Alaskan North Slope geology: Bakersfield, Calif., Pacific Section Society of Economic Paleontologists and Mineralogists, book 50, p. 797-830.

Isaacs, C.M., 1992, Uranium, thorium, and other trace elements in strip samples from cores 128-798B-13H through -15H, in Tamald, K., Suyehiro, K., Allan, J., McWilliams, M., et al., Proceedings of the Ocean Drilling Program, Scientific Results, v. 127/128, pt. 2, p. 1367-1372.

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Jones, H.P., and Speers, R.G., 1976, Permo-Triassic reservoirs of Prudhoe Bay field, North Slope, Alaska, in Braunstein, J., ed., North American oil and gas fields: American Association of Petroleum Geologists Memoir 24, p. 23-50.

Magoon, L.B., and Bird, K.J., 1987, Alaskan North Slope petroleum geochemistry for the Shublik Formation, Kingak Shale, pebble shale unit, and Torok Formation, in Tailleur, I., and Weimer, P., eds., Alaskan North Slope Geology: Pacific Section Society of Economic Paleontologists and Mineralogists Book 50, v. 1, p. 145-160.

Magoon, L.B., and Bird, K.J., 1988, Evaluation of petroleum source rocks in the National Petroleum Reserve in Alaska, using organic-carbon content, hydrocarbon content, visual kerogen, and vitrinite reflectance, in Gryc, G., ed., Geology and Exploration of the National Petroleum Reserve in Alaska, 1974 to 1982: U.S. Geological Survey Professional Paper 1399, p. 381-450.

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Moore, T.E., Wallace, W.K., Bird, K.J., Karl, S.M., Mull, C.G., and Dillon, J.T., 1992, Stratigraphy, structure, and geological synthesis of northern Alaska: U.S. Geological Survey Open-File Report 92-330,183 p.

Mull, C.G., Tailleur, I.L., Mayfield, C.F., Ellersieck, I., and Curtis, S., 1982, New upper Paleozoic and lower Mesozoic stratigraphic units, central and western Brooks Range, Alaska: American Association of Petroleum Geologists Bulletin, v. 66, p. 348-362.

Palmer, A.R., 1983, The decade of North American geology 1983 geologic time scale: Geology, v. 11, p. 503-504.

Parrish, J.T., 1987, Lithology, geochemistry, and depositional environment of the Triassic Shublik Formation, northern Alaska, in Tailleur, I., and Weimer, P., eds., Alaskan North Slope Geology: Pacific Section Society of Economic Paleontologists and Mineralogists Book 50, v. 1, p. 391-396.

Piper, D.Z., and Isaacs, CM., 1995, Minor elements in Quaternary sediment from the Sea of Japan: A record of surface-water productivity and intermediate-water redox conditions: Geological Society of America Bulletin, v. 107, p. 54-67.

Piper, D.Z., and Isaacs, C.M., Geochemistry of minor elements in the Monterey Formation, California: Seawater chemistry of deposition: U.S. Geological Survey Professional Paper (in press).

30