Black shales have been of increasing interest in recent years due to their oil and gas potential, but also because many are enriched in nonfuel "unconventional" critical elements such as cobalt, chromium, molybdenum, nickel, platinum group elements, rhenium, and vanadium. Critical metals residing in shales presented a challenge to economic recovery, and thus, development of deposits was "shelved" because metals could not be recovered by traditional methods. With recent advances in metals extraction, it may be feasible to mine these deposits.
Re-assessing the potential for critical elements in shales is important and timely because of new analytical techniques and advances in extraction technology. The USGS is in a prime position to conduct a modern assessment of such deposits in the U.S. This requires compiling geologic, sedimentologic, geochemical, and isotopic data already available and collecting new data in selected areas. Project objectives are to improve the understanding of critical mineral enrichment in black shales and improve accuracy of resource assessments. The project consists of three main tasks:
Johnson, C.A., Dumoulin, J.A., Burruss, R.A., and Slack, J.F., 2015, Depositional conditions for the Kuna Formation, Red Dog Zn-Pb-Ag-barite district, Alaska, inferred from isotopic and chemical proxies: Economic Geology, 110(5), p. 1143-1156, doi:10.2113/econgeo.110.5.1143.
Johnson, S.C., Large, R.R., Coveney, R.M., Kelley, K.D., Slack, J.F., Steadman, J.A., Gregory, D.D., Sack, P.J., and Meffre, S., 2017, Secular distribution of highly metalliferous black shales corresponds with peaks in past atmosphere oxygenation: Mineralium Deposita, First online 17 May 2017, doi:10.1007/s00126-017-0735-7.
Kelley, K.D., Selby, D., Falck, H., and Slack, J.F., 2017, Re-Os systematics and age of pyrite associated with stratiform Zn-Pb mineralization in the Howards Pass district, Yukon and Northwest Territories, Canada: Mineralium Deposita, 52(3), p. 317-335, doi:10.1007/s00126-016-0663-y.
Scott, C., Kelley, K.D., and Slack, J.F., 2014, The Geobiology of Sediment-Hosted Mineral Deposits, in Kelley, K.D., and Golden, H.D., eds., Special Publication Number 18 Building Exploration Capability for the 21st Century: Society of Economic Geologists, p. 17-35.
Scott, C., Slack, J.F., and Kelley, K.D., 2017, The hyper-enrichment of V and Zn in black shales of the Late Devonian-Early Mississippian Bakken Formation (USA): Chemical Geology, 452, p. 24-33, doi:10.1016/j.chemgeo.2017.01.026.
Slack, J.F., Falck, H., Kelley, K.D., and Xue, G.G., 2017, Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization: Mineralium Deposita, 52(4), p. 565-593, doi:10.1007/s00126-016-0680-x.
Slack, J.F., Selby, D., and Dumoulin, J.A., 2015, Hydrothermal, biogenic, and seawater components in metalliferous black shales of the Brooks Range, Alaska: Synsedimentary metal enrichment in a carbonate ramp setting: Economic Geology, 110(3), p. 653-675, doi:10.2113/econgeo.110.3.653.
Dumoulin, J.A., Johnson, C.A., Kelley, K.D., Jarboe, P.J., Hackley, P.C., Scott, C., and Slack, J.F., 2016, Depositional setting of metalliferous, organic-rich black mudrock in the Heath Formation (Upper Mississippian), central Montana: Geological Society of America Abstracts with Programs, Vol. 48, No. 7, doi:10.1130/abs/2016AM-279160.
Dumoulin, J.A., Johnson, C.A., Kelley, K.D., Scott, C., and Slack, J.F., 2015, Transgressive-regressive cycles in the highly metalliferous, oil shale-bearing Heath Formation (Upper Mississippian), central Montana: AAPG Annual Convention and Exhibition, Denver, CO., May 31-June 3, 2015. View Dumoulin 2015 Heath Formation AAPG abstract.
Dumoulin, J.A., and Whidden, K.J., 2015, Transitional facies of the Triassic Shubik and Otuk Formations at Surprise Creek, northwest Alaska: AAPG Annual Convention and Exhibition, Denver, CO., May 31-June 3, 2015. View Dumoulin 2015 AAPG abstract.
Johnson, C.A., Slack, J.F., and Kelley, K.D., 2014, Depositional environment of mudstone host rocks at the Howards Pass Zn-Pb deposits, Yukon Territory, Canada: Insights from iron speciation, sulfur isotopes, and bulk Fe/Al and Mo/TOC ratios: Geological Society of America Abstracts with Programs, Vol. 46, No. 6, p. 250. View Johnson 2014 GSA abstract.
Kelley, K.D., Benzel, W.M., and Pfaff, K., 2013, Preliminary mineralogy and geochemistry of metal-rich (Mo-Ni-V-Zn) oil shale of the Carboniferous Heath Formation, Montana, USA: 12th Biennial SGA meeting, 12-15 August 2013, Uppsala, Sweden.
Kelley, K.D., Pfaff, K., Benzel, W., Dumoulin, J.A., Johnson, C., Scott, C., and Slack, J.F., 2015, Extent of metalliferous intervals and principal hosts of Mo, Ni, V, and Zn in oil shale of the Mississippian Heath Formation, Montana, USA: 13th Biennial SGA Meeting, 24-27 August 2015, Nancy, France.
Scott, C.T., Slack, J.F., and Kelley, K.D., 2014, An aqueous sulphide control for hyper-enrichment of trace metals in black shales: GAC-MAC 2014 Annual Meeting, 21-23 May 2014, Fredericton, New Brunswick, p. 246-247. View GAC-MAC 2014 abstracts. [PDF file, 9.2 MB]
Scott, C., Slack, J.F., and Kelley, K.D., 2013, The origin of vanadium hyper-enriched black shales: Geological Society of America Abstracts with Programs, Vol. 45, No. 7, p. 427. View Scott 2013 GSA abstract.
Smith, S.M., Neilson, R.T., and Giles, S.A., 2015, Levelling and merging of two discrete national-scale geochemical databases—a case study showing the surficial expression of metalliferous black shales: 27th International Applied Geochemistry Symposium Abstracts, 20-14 April 2014, Tucson, AZ.
Slack, J.F., 2014, Lithogeochemical studies of stratabound mineral deposits: Lessons and insights Keynote: GAC-MAC 2014 Annual Meeting, 21-23 May 2014, Fredericton, New Brunswick, p. 254-255. View GAC-MAC 2014 abstracts. [PDF file, 9.2 MB]
Slack, J.F., Selby, D., and Dumoulin, J.A., 2014, Geochemical and Os isotope evidence for multiple metal sources in Mississippian black shales of the Lisburne Group, northern Alaska Keynote: GAC-MAC 2014 Annual Meeting, 21-23 May 2014, Fredericton, New Brunswick, p. 254. View GAC-MAC 2014 abstracts. [PDF file, 9.2 MB]
Slack, J.F., Rosa, D., and Falck, H., 2015, Oxic to anoxic transition in bottom waters during formation of the Citronen Fjord sedex Zn-Pb deposit, north Greenland: 13th Biennial SGA Meeting, 24-27 August 2015, Nancy, France.
Karen Duttweiler Kelley
Central Mineral and Environmental Resources Science Center