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Dictator Opal Mine, Northern Bullion Mountains, San Bernardino County, California Gregg Wilkerson, 2020 yosoygeologo@gmail.com

Acknowledgement and Disclaimer The information in this paper is taken largely from published and public sources. I have reproduced this material and present it pretty much as I found it, not trying to harmonize discrepancies in mine or geologic descriptions. I have changed verb tenses for readability and have used some paraphrase. I have expanded abbreviations or special characters with full text (e.g. feet instead of ft., inches instead of “) Italics indicate quotations. Authors of the original information are indicated at the end of each paragraph. Paragraphs without a citation are our own materials. The maps in this report have been compiled and rectified from digital and paper copies of original sources that were made at different scales and in different geographic projections. Therefore, many of the maps had to be adjusted or stretched. They do not fit perfectly. Most are accurate to within 100 feet, but reproduction and projection errors can be as much as 300 feet for some maps. PLSS means Public Land Survey System. That survey data was obtained from the U.S. Bureau of Land Management website. MRDS, 2011, Mineral Resources Data System, U.S. Geological Survey, https://mrdata.usgs.gov/mrds/. This database relies on records that, in many cases, are inaccurate or imprecise. For example, if a report describes a mine as being in “Section 9”, with no other information, MRDS plots the mine location in the center of the section. If a mine is reported in “SW ¼” of a section, MRDS plots the mine in the center of that SW quarter-section. Where I could confidently adjust an MRDS location of a mineral deposit to features identifiable in aerial photographs or topographic maps, I did so. Help me make this report better. If you have any photographs, memories or reports for this mine that you can share, please send them to yosoygeologo@gmail.com so we can incorporate into this paper. LOCATION: (MRDS, 2011) 7N 9E Sec. 18 SBM 34.70062000030 -116.08335000000 *NW~ Sec. 18, T.7N., R.9E., SBBM, San Bernardino County (Southern Pacific, 1964, p. 189; Gamble, 1957). OWNER Bureau of Land Management GEOLOGY Opal in basalt (Southern Pacific, 1964, p. 189)

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GEOLOGIC MAPPING 1:250,000

Bortugno and Spittler (1986) mapped the area of the Dictator Opal Mine as Miocene intrusive volcanics (Mvb) and older dissected alluvial fans (Qod)

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1:100,000

Phelps and others (2012) mapped the area of the Dictator Opal Mine as intermediate to mafic volcanic bedrock units and alluvial units Qaa and Qiaeo:

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1:62,500 Dibblee (1967a) and Dibblee and Minch (redrafting 2008f) mapped the area of the Dictator Opal Mine as near the contact between Quaternary-Tertiary Basalt of Ash Hill (QTb) and Quaternary older alluvium (Qoa) or Quaternary alluvium (Qa).

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1:24,000

Collier and others (1957) mapped the area of the Dictator Opal Mine as Quaternary-Tertiary basalt (QTb).

DEVELOPMENT Open pit (Southern Pacific, 1964, p. 189) A vertical shaft approximately 15 feet deep was dug in basalt A few broken fragments of opal and basalt are scattered about the open shaft. The opaline material has no economic value but would probably be of interest to mineral collectors. This prospect was noted and briefly discussed by Cohen (1957) (Gamble, 1957, p. 5). REFERENCES Bortugno E.J. and T.E. Spittler, 1986, Geologic Map of the San Bernardino Quadrangle, 1:250,000, Regional Geologic Map Series, Map No. 3A (Geology), Sheet 1 of 5. Cohen, C.L.D., 1957, Geology end mineral resources of Township 7 North, Ranges. 7 and 8 East, SBB&M, (unpublished ). Bernardino County, California: Southern Pacifice Company . Collier, John T., C.L.D. Cohen and J.S. Vanderpool, 1957, Geology and Mineral Resources of Part of Townships 6 and 7 North, Range 8 East Half, San Bernardino Meridian, San Bernardino County, California – Includes Bagdad-Chase and Ragtown Gold-Copper District, Unpublished report, Southern Pacific Company in support of Minerals or Industry, vol. 3, p. 115. Collier, John T. and J.S Vanderpool, 1957, Aerial Economic Geology of T.6N, R.07 and 08E, SBM, Southern Pacific Corporation, Unpublished map in support of Minerals for Industry, Southern California Volume III, Special Publication 95, California Division of Mines and Geology, 1987; additions by R, Antil, A Cunningham an M. Schafer, 1958.

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Southern Pacific Company, 1964, Minerals for Industry, Southern California, Volume 3, P. 115 Dibblee, T.W., 1967d, Geologic map of the Ludlow quadrangle, San Bernardino County, California: U.S. Geological Survey, Miscellaneous Geologic Investigations Map I-477, scale 1:62,500. Dibblee, T.W., and Minch, J.A., 2008f, Geologic map of the Ludlow & Bagdad 15 minute quadrangles, San Bernardino County, California: Dibblee Geological Foundation, Dibblee Foundation Map DF-396, scale 1:62,500. Gamble, James, 1959, Geology and Mineral Resources of Township 7 North Ranges 9 and 10 East, San Bernardino Base and Meridian, San Bernardino County, California, Unpublished report in support of Oesterling, W.A. and Spurck, W.H. (1964), Minerals for Industry, Summary of Geological Survey 1955 - 1961: Vol III - 242 pp., Southern California, Southern Pacific Company, San Francisco, CA 94105: Miller, D. M., Howard, K. A., and John, B. E., 1982, Preliminary geology of the Bristol Lake region: in Cooper, J. D., compiler, Geologic excursions in the California Desert: Geological Society of America 78th Annual Meeting Cordilleran Section, Anaheim, CA, April 19-21, 1982, p. 91-100. Oesterling, W.A. and Spurck, W.H. (1964), Minerals for Industry, Summary of Geological Survey 1955 - 1961: Vol III - 242 pp., Southern California, Southern Pacific Company, San Francisco, CA 94105: 189. Phelps, G.A., Bedford, D.R., Lidke, D.J., Miller, D.M., and Schmidt, K.M., 2012, Preliminary surficial geologic map of the Newberry Springs 30' x 60' quadrangle, California: U.S. Geological Survey, Open-File Report OF-2011-1044, scale 1:100,000. Rogers, Thomas H., 1967, Geologic Map of California, Olaf P. Jenkins Edition, San Bernardino Sheet, California Division of Mines and Geology, Scale 1:250,000. Southern Pacific Company, 1964, Minerals for Industry, Vol. III -Southern California, p. 189. Tucker, W.B. and R.J. Sampson, 1940, Economic Mineral Deposits of the Newberry and Ord Mountains, San Bernardino County, California Journal of Mines and Geology, State Division of Mines, Vol., 36, p. 233. Tucker, W.B. and R.J. Sampson, 1943, Los Angeles Field District, Journal of Mines and Geology, State Division of Mines, Vol., 39, No. 1, p. 443. Wright, L.A., et al (1953), Mines and mineral resources of San Bernardino County, California: California Journal of Mines and Geology: 49(1-2): Table No. 78, p. 28. MAPS

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Figure 1. Regional topographic map of the Dictator Opal Mine. Scale 1:100,000.

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Figure 2. Regional land status map of the Dictator Opal Mine. Data from BLM. Scale 1:100,000

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Figure 3. Regional geologic map of the Dictator Opal Mine. Scale 1:100,000.

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Figure 4. Topographic map of the Dictator Opal Mine. Scale 1:24,000.

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Figure 5. Area geologic map of the Dictator Opal Mine. Scale 1:24,000.

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Figure 6. Area geologic map of the Dictator Opal Mine. Scale 1:24,000.

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Figure 7. Topographic map of the Dictator Opal Mine. Scale 1:10,000. From USGS and ESRI.

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Figure 8. Geologic map of the Dictator Opal Mine. Scale 1:10,000.

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Figure 9. Aerial photograph of the Dictator Opal Mine. Scale 1:3,000. From ESRI.