REPORT OF INVESTIGATION Noo 1 UTAH GEOLOGICAL AND MINERALOGICAL SURVEY COAL RESOURCES OF THE ANTIMONY - JOHNvS VALLEY AREA GARFIELD COUNTY, UTAH (NORTHWEST EXTENSION OF KAIPAROWITS COAL FIELD) by Armand Jo Eardley and Robert E~ Cohenour January 1963 In cooperation with the Utah Geological and Mineralogical Survey and the College of Mines and Mineral Industries of the University of Utah Prepared at the request of the State Land Board COAL RESOURCES OF THE ANTIMONY - JOHN'S VALLEY AREA GARFIELD COUNTY, UTAH (NORTHWEST EXTENSION OF KAIPAROWITS COAL FIELD) by Armand Jo Eardley and Robert Eo Cohenour January 1963 Prepared at the request of the State Land Board COAL RESOURCES OF THE ANTIMONY - JOHN'S VALLEY AREA GARFIELD COUNTY, UTAH CONCLUSIONS Only a part of the acreage s~bmitted for investigation is recommended for aquisition (see Figure 1), and this on a non-mineral lands exchange basiso The acreage recommended is in an area consisting mainly of an inferred coal reserve based on four drill holes and meager surface geologic datao The inferred reserve is calculated to contain approxi­ mately 327 million tons of soft coal ranking from lignite to subbituminouso The reserve lies between 350 and 420 feet below the valley floor o Since the reserve is not proven or measured, and since .~.. it will not be commercial for a long time in the future it is recommended that non-mineral lieu lands be used for ex­ change purposes, if possibleo It is further recommended that in case surface title is conveyed, or the lands be declared subjected to multiple use, that provision be made that all rights, buildings, and improvements be relinquished without indemnity to the State. This is necessary because present knowledge indicates that an open pit operation would be more economic and feasible than an underground operationo The coal resources of the Antimony - John's Valley area comprise a rather remote future reserve since market con­ ditions are not favorable in light of the rather low rank and low calorific value of the coal, amount of overburden, and distance to present market areas. Also the absence of abundant water at present precludes the development of a -1- -2- modern steam electric generating plant in the area. If an open pit operation materializes on this reserve, further engineering studies regarding the placement of 'spoil' (stripped rock) should be made in order that the mined-out area be easily converted into a suitable reservoir for flood control and irrigationo INVESTIGATION Wells drilled by the U. S. Geological Survey in the study of ground water conditions along the East Fork of the Sevier River in what is called John "s Valley, about 15 miles south of Antimony, resulted in the discovery of coal. The present report is an attempt to evaluate these coal beds for purposes of lieu land exchange, and has been prepared at the request of the State Land Board. See Figures 1 and 2. The area was visited on December 27, 1962 by A. J. Eardley and Rc Eo Cohenour. The examination was sufficient to pro- vide confidence in the preliminary reconnaisance geology shown on the attached geologic maps (Figures 3 and 4). They are enlargements of part of the unpublished preliminary State geologic map being compiled by Dr. Lehi Hintze of Brigham Young University directed by Dro William Lee Stokes of the University of Utah for the Utah State Land Board. Supplementary information was taken from the unpublished report nA Reconnaissance Study of the Coal Resources of South­ western Utah" by R. Ao Robison; Uo So Geol. Surv. Coal In­ vestigations Map C-49; "Geology and Fuels Resources of the Orderville-Glendale Area, Kane County, Utah" by W. B. Cashion; a textbook nCoal" by E .. S. Moore, John Wiley and Sons; and the following maps in the U.S.G.S. Army Map Service series: NJ 12-7 Cedar City and NJ 12-8 Escalante. The logs of the wells drilled in John's Valley as furnished kindly by the UoS. Geological Survey are given in the supplement at the end of the report. -3- The particular lands designated by the State Land Board to be investigated for their coal reserves are as follows~ Lands situated in John's Valley in the northwest part of Garfield County, Utah Subdivision Sec TWP6 Range Acres wt 1 338 2W 320600 All 3 n 636641 All 4 " tt 639~04 All 5 tt " 640.00 All 6 " " 626.40 All 7 1t n 626 .18 All 8 tt n 640.00 All 9 1t n 640.00 All 10 n n 640.00 E~} EtW 11 f1 n 480.00 NEt 12 tt tt 160.00 Et, E!Wt 14 " tt 480600 NEt, NtSEt, N!NWt, SWiNWt 15 tt n 360.00 All 21 It n 640.00 swt, NtSEt, SWtSEt 22 f1 n 280.00 S!NEt, StNWi, NWiNWt 22 tt n 200.00 E!, E!SWt, NWtSWt 23 tt tt 440000 S!NWt, NEiNWi 23 It n 120.00 E!, E!W! 26 n n 480.00 Et8Wt 27 tt n 80.00 WtWt, Et 28 It n 480.00 All 33 n n 640600 W!E~, SEt8Et, NWt 34 n n 360.00 N!Swt, swt8wi 34 n n 120.00 -.1E1 W1NE!. E1NW!. NW!.SE!. 35 n E 2 2' 2 4' 2 4' 4 4 " 360.00 Also beg at the NW Cor of the NEtNWt, th 8 160 rods th E 12 rds, th N 160 rods th W 12 rds to place of beg 28 n n 12.60 ~4- Subdivision SecD Twpo Ran~e Acres SW1.4 1 33S 3W 160.00 tt Tt E1.2 12 320.00 Total 11,580.63 ENGINEERING AND ECONOMIC CONSIDERATIONS The area investigated comprises a high, broad north~ trending mountain valley situated between the west lying Sevier Plateau and the east lying Escalante Mountains of the Aquarius Plateau in northwest Garfield County of south central Utah (see Figure 2)0 Elevations in the area range from 7400 feet to over 8600 feet for a maximum relief of 1200 feeto The area is not well watered but the north-flowing East Fork of the Sevier River provides some water for the inhabi­ tants whose livelihood is mainly ranchingo The area is transected by State Highway 22, a graveled road which passes through Widtsoe (abandoned) and northward through Antimony from which point it is paved to U. S. High­ way 89 in the vicinity of Junction, the county seat of Piute County (see Figure 2)0 Presently, shipping routes to the nearest rails or transcontinental highways will be via the above route 0 The overall distance from the center of the area to Junction is approximately 30 miles with the first 10 miles being graveled and somewhat sinuous in the vicinity of Antimony which also is the nearest minor supply point. The largest and lower portion of the area is mainly covered by alluvium and some gravelso Tertiary and Quaternary volcanics, mainly basaltic lavas, cap the gently dipping, friable, soft, pinkish~orange clay and siltstones of the Ter~ tiary Wasatch formation which crops out along both sides of the valley (see Figure s 3 and 4) 0 Subsurface geology comprises the following formations~ Tertiary Wasatch 0 to 500 feet clays and silts Cretaceous Kaiparowits fm 1200 to 1800 feet - (coal section) & Wahweap ss sandstone and shale, 3 to 1 ratio Straight Cliffs 400 to 1000 feet - sandstone minor shale and thin lenses of coal Tropic shale 200 to 500 feet - black shale with some thick lenses of coal near base and at top Dakota ss 40 to 80 feet - sandstone and conglom­ erate with minor lensing coal beds The coal beds penetrated are believed to be in the upper coal zone of the Tropic formationG The coals range in thickness from 3 to 30 feet and lie from 350 to 420 feet below the valley flooro Drilling fragments observed by both U.S. Geolo Survey geologist on the wells and by the authors appear to be between lignite and subbituminous in rank 0 Such coal would have calorific values between 7000 and 13,800 BTU (average for lignite to sUbbituminouso Refer to nCoal" by Eo So Moore, John Wiley & Sonsa) If the interpretation is correct that the coal beds penetrated are ~n the upper part of the Tropic formation, then the central part of the valley appears to be a horst or uplifted blocko The exact position of the flanking faults can only be inferred since there has been no recent movement on the faults to disclose their position, and the wells are not numerous enough to define themo Mapping and examination of the formations overlying the Tropic shale which crop ,out in the mountains on either side of the valley are not sufficient to determine adequately -6- whether or not they contain coal beds, but as far &s known none has been reported. COAL RESERVES A reserve of approximately 6,644,800 tons of the sub- ~~ bituminous (?) is indicated in a i mile radius around Test Well No. 17 in sections 33 and 34 of T. 33 S., R. 2 W. and sections 3 and 4 of T. 34 So, R. 2 W. Inferring the same tenor of coal in To 33 and 34 S., R. 2 W., more specifically in sections 21, 22, 27, 28, 33, and 34, T. 33 S., R. 2 W. and in sections 2,3,5,8,9,10,15,16,17,19,20,21, 22, 28 and 29, To 34 So, R. 2 W. there might be an approxi­ mate reserve of 320,380,000 tons there.