of
Sample: Sample No. At. ditch 900
Locality: Field No. At. ditch 900
Description: No Data
    *Atlantic Richfield Susie Unit no. 1 - drilled at junction of Ivishak and Sagavanirktok Rivers.
Location: Alaska Quadrangle: Arctic
Reference
Title: Report on Referred Fossils ,  1966 (11/28)
Microfossil slides examined were from Atlantic Richfield Susie Unit no. 1, northern Alaska sent by Richard E. Anderson of Atlantic Richfield and Andrew Marianos of Humble Oil and Refining Co. An assemblage of well preserved arenaceous Foraminifera and a smaller assemblage of calcareous species of Late Cretaceous (Turonian-Senonian) age were identified on slides from core and ditch samples from the interval of 1160 feet through at least 7212 feet. Foraminifera in samples from depths from the lowest thousand feet of this interval are not as well preserved nor as readily identifiable as those from 1160-6141 feet. More than 20 species are the same as those known from the Schrader Bluff and Seabee Formations. These include such species as Haplophragmoides rota Nauss, H. kirki Wichenden, H. bonanzensis Stelck and Wall, large specimens of Saccammina lathrami Tappan (common in Upper Cretaceous beds of northern Alaska), Ammodiscus cretaceous (Reuss), Verneuilinoidas fischeri Tappan, Verneuilinoides sp. (a massive form), Gaudryina sp., Dorothia sp. Arenobulimina torula Tappan, Trochanmina ribstonensis Wickenden. T. whittingtoni Tappan, Eoeponidella aff. E. strombodes Tappan, Pullenia cf. P. cretacea Cushman, Praebulimina carseyae (Plummer), P. venusae (Nauss), Nonionella taylorensis Hofker, Causcasina vitrea (Cushman and Parker), Quinqueloculina sphaera Nauss, Neobulimina canadensis Wickenden, Neobulimina albertensis (Stelck and Wall), and a large species of Hedbergelia.

Many of the ditch samples from depths below 7212 feet carry some of the species from the Upper Cretaceous beds; the sidewall core samples from the same depths are barren except for a specimen of Trochammina sp. in a sample from 7361 feet. This has a few chambers and resembles T. webbi Stelck and Wall from the central part of the Kaskapau Formation, Spirit River, Alberta, Canada, but may have closer affinities to T. mcmurrayensis Mellon and Wall from the McMurray Formation of Albian age in Alberta.

Fossils of Cenomanian age were not recognized and there is very little evidence of Albian age Lower Cretaceous fossils in samples from this well. Those found are few and scattered. Entirely lacking is a sharply defined Verneuilinoides borealis fauna of middle to late Albian age so common over much of the foothills of northern Alaska and in the subsurface of many of the coastal plain wells. Possibly nonmarine beds of Early Cretaceous age may be extensively developed in the area of this well, or else there is a tremendous thickness of Upper Cretaceous beds.

A few specimens of what appear to be Verneuilinoides borealis were observed on slides from core 10 (9235-9245 ft.). In a sample from 10,091 feet, from core 11 (10,091-10,099 ft.), occur a specimen of Quadramorphina ruckerae (Tappan) and a specimen of Conorboides umiatensis (Tappan), two forms heretofore identified only from Albian beds in northern Alaska. Four specimens of Conorboides umiatensis also occur on a slide from a ditch sample at 8440 feet. Two specimens that are possibly Haplophragmoides topagorukensis Tappan of Albian age occur in a ditch sample from 7830 feet and in a side wall core sample at 10,042 feet a questioned H. topagorukensis was noted. Albian fossils are wanting in other samples and the ditch samples carry Upper Cretaceous Foraminifera. Questioned specimens of Verneuilinoides borealis Tappan occur on slides of ditch samples from 7550 feet and 8440 feet.

In summation, beds through at least 7212 feet are of Late Cretaceous (Turonian and Senonian) age. Beds of Early Cretaceous (Albian) age are identified from Foraminifera in the last two cores (9235-9345 ft. and 10,09-10,099 ft.) and in a ditch sample at 8440 feet. Possible Albian forms occur higher at 7361 feet, 7550 feet, and at 7830 feet. The test well does not have a prominently defined zone of Lower Cretaceous fossils. A “boundary” between Colvile and Nanushuk beds may be somewhere between 7212 feet and 7361 feet.

The accompanying faunal chart indicates identifications and distribution of fossils in the material examined.

Explanation:
Number of specimens (3) less than 12
Rare (R) specimens (few, not counted)
Common (C) specimens (12-15)
Abundant (A) specimens (16-50)
Very Abt. (V) specimens (over 50)
Fragment (f)
Atlantic Richfield samples (At.ditch, At.sidewall, cores)
Remaining samples from Humble Oil & Refining Co.

Report by: Harlan Bergquist
Referred by: Richard E. Anderson
Age: Late Cretaceous
Atlantic Richfield Susie Unit no. 1
 Interval
core 11) 1009910099
core 11) 1009710097
core 11) 1009510095
core 11) 1009310093
core 11) 1009110091
At. sidewall 1004210042
At. sidewall 1000410004
At. sidewall 97729772
At. sidewall 96809680
At. sidewall 96009600
94809480
94509450
94009400
At. sidewall 93909390
93509350
93009300
92509250
core 10) 92469246
core 10) 92459245
core 10) 92449244
core 10) 92439243
core 10) 92419241
core 10) 92409240
core 10) 92399239
core 10) 92389238
core 10) 92379237
core 10) 92369236
core 10) 92359235
At. sidewall 92009200
92009200
91509150
At. sidewall 91009100
91009100
90509050
At. sidewall 90009000
90009000
89508950
89308930
89008900
88608860
At. sidewall 88008800
At. sidewall 87508750
87108710
At. sidewall 87028702
86808680
86508650
86308630
At. sidewall 86168616
85708570
85308530
85008500
At. sidewall 84858485
84708470
At. ditch 84408440
84408440
84008400
83708370
83408340
At. ditch 83008300
83008300
At. sidewall 82748274
82708270
At. sidewall 82328232
82308230
At. ditch 82008200
82008200
81608160
At. sidewall 81508150
81308130
At. ditch 81008100
81008100
80908090
80508050
At. ditch 80008000
80008000
79707970
79407940
At. ditch 79007900
79007900
At. sidewall 78887888
78607860
At. sidewall 78407840
78307830
At. ditch 78007800
78007800
77707770
At. sidewall 77437743
77307730
At. ditch 77007700
77007700
At. sidewall 76807680
76707670
76307630
At. ditch 76007600
76007600
75507550
At. ditch 75007500
75007500
At. sidewall 74977497
At. sidewall 74747474
74507450
74007400
At. ditch 74007400
At. sidewall 73617361
73607360
73207320
At. ditch 73007300
72807280
72407240
At. sidewall 72157215
At. sidewall 72127212
At. ditch 72007200
72007200
At. sidewall 71437143
71007100
At. ditch 70607060
70307030
At. sidewall 70257025
At. ditch 70007000
70007000
69806980
69606960
69306930
At. sidewall 69016901
At. ditch 69006900
69006900
68706870
68406840
At. ditch 68006800
68006800
67506750
At. sidewall 67166716
At. ditch 67006700
67006700
66606660
66306630
At. sidewall 66106610
At. ditch 66006600
66006600
65706570
65406540
At. sidewall 65236523
At. ditch 65006500
65006500
64706470
At. sidewall 64606460
64306430
At. sidewall 64266426
At. ditch 64006400
64006400
63606360
63206320
At. ditch 63006300
63006300
At. sidewall 62706270
62606260
At.sidewall 62336233
62306230
62006200
61406140
core 9) 6131-61416131 - 6141
At. ditch 61006100
61006100
60706070
60306030
At. ditch 60006000
At. sidewall 59975997
At. ditch 59005900
At. sidewall 58065806
At. ditch 58005800
At. sidewall 53385338
core 7) 5165-51795165 - 5179
core 6) 4641-46624641 - 4662
core 5) 4277-42874277 - 4287
At. sidewall 42314231
core 4) 3821-38393821 - 3839
core 3) 3072-30983072 - 3098
core 2) 2605-26352605 - 2635
At. sidewall 25252525
At. sidewall 22402240
At. sidewall 20902090
At. sidewall 20002000
At. sidewall 17701770
At. sidewall 14801480
core 1) 1328-13481328 - 1348
At. sidewall 13151315
At. sidewall 12831283
At. sidewall 12601260
At. sidewall 11601160
At. ditch 900900