List of Earth MRI focus areas with mineral system = Marine chemocline

Marine chemocline (bathtub rim)

Marine chemocline systems operate where basin brines disharge into the ocean. Consequent increases in bioproductiviy produce metalliferous black shales. Changes in ocean chemistry (oceanic anoxic events) and development of chemoclines result in chemical sedimentation of phosphate and Mn and Fe carbonates and oxides.

Color on map:

Deposit types

Name	Commodities	Critical minerals
Black shale	Stone coal, petroleum, V, Ni, Mo, Au, PGE	V, Re, PGE, Cr, U
Phosphate	Phosphate fertilizer	F, REE, Cr, U
Iron-manganese	Fe, Mn, Co	Mn, Co
Superior iron	Fe	not-applicable

References

Lefebure, D.V., and Coveney, R.M., Jr., 1995, Shale-hosted Ni-Zn-Mo-PGE, in Lefebure, D.V., and Ray, G.E., eds., Selected British Columbia mineral deposit profiles, volume 1--Metallics and coal: British Columbia Ministry of Energy of Employment and Investment, Open File 1995-20, p. 45-48.
Force, E.R., Paradis, S., and Simandl, G.J., 1999, Sedimentary manganese, in Simandl, G.J., Hora, Z.D., and Lefebure D.V., eds., Selected British Columbia mineral deposit profiles, volume 3--Industrial minerals: British Columbia Ministry of Energy and Mines, Open File 1999-10 p. 47-50.
Emsbo, P., 2000, Gold in sedex deposits, in Hagemann, S.G., and Brown, P.E., eds., Reviews in economic geology, volume 13--Gold in 2000: Littleton, Colo., Society of Economic Geologists, Inc., p. 427-437.
Emsbo, P., McLaughlin, P.I., Breit, G.N., du Bray, E.A., and Koenig, A.E., 2015, Rare earth elements in sedimentary phosphate deposits--Solution to the global REE crisis?: Gondwana Research, v. 27, p. 776-785, accessed April 18, 2020, at https://doi.org/10.1016/j.gr.2014.10.008.
Emsbo, P., McLaughlin, P.I., du Bray, E.A., Anderson, E.D., Vandenbroucke, T.R.A., and Zielinski, R.A., 2016b, Rare earth elements in sedimentary phosphorite deposits--A global assessment, chap. 5 of Verplanck, P.L, and Hitzman, M.W., eds., Reviews in economic geology, volume 18--Rare earth and critical elements in ore deposits: Littleton, Colo., Society of Economic Geologists, Inc., p. 101-114.
Cannon, W.F., Kimball, B.E., and Corathers, L.A., 2017, Manganese, chap. L of Schulz, K.J., DeYoung, J.H., Jr., Seal, R.R., II, and Bradley, D.C., eds., Critical mineral resources of the United States--Economic and environmental geology and prospects for future supply: U.S. Geological Survey Professional Paper 1802, p. L1-L28, accessed April 18, 2020, at https://doi.org/10.3133/pp1802L.

Source: Hofstra, A.H., and Kreiner, D.C., 2020, Systems-Deposits-Commodities-Critical Minerals Table for the Earth Mapping Resources Initiative: U.S. Geological Survey Open-File Report 2020-1042, 24 p., https://doi.org/10.3133/ofr20201042.

List of Earth MRI focus areas with mineral system = Marine chemocline

25 focus areas match these criteria.

Focus area	Region	States	Mineral Systems	Deposit types	Commodities
Triassic Phosphate REE	Alaska	Alaska	Marine chemocline	Phosphate	phosphate fertilizer; uranium
Upper Mississippian (Visean) Phosphate REE	Alaska	Alaska	Marine chemocline	Phosphate	phosphate fertilizer; uranium
Chamberlain district	North Central	South Dakota	Marine chemocline	Iron-manganese	iron
Manganese (Mn) in iron-formations	North Central	Michigan; Minnesota; Wisconsin	Marine chemocline	Iron-manganese	iron
Mesoproterozoic Phosphate	North Central	Michigan; Wisconsin	Marine chemocline	Phosphate	phosphate fertilizer; uranium
Upper Ordovician Phosphate (Rawtheyan and Richmondian)	North Central	Alabama; Iowa; Illinois; Indiana; Kentucky; Michigan; Minnesota; Missouri; Ohio; Oklahoma; Tennessee; Wisconsin	Marine chemocline	Black shale; Iron-manganese; Phosphate	copper; gold; iron; molybdenum; petroleum; phosphate fertilizer; stone coal; uranium
Aroostook County manganese	Northeast	Maine	Marine chemocline	Iron-manganese	iron
Blue Hill manganese prospects	Northeast	Maine	Marine chemocline	Iron-manganese	iron
Bowers Mountain black shale	Northeast	Maine	Marine chemocline	Black shale	copper; gold; molybdenum; petroleum; stone coal; uranium
Devonian Marcellus black shale	Northeast	Kentucky; Maryland; New York; Ohio; Pennsylvania; Virginia; West Virginia	Marine chemocline	Black shale	copper; gold; molybdenum; petroleum; stone coal; uranium
Dover-Foxcroft manganese prospect	Northeast	Maine	Marine chemocline	Iron-manganese	iron
Greenfield manganese prospects	Northeast	Maine	Marine chemocline	Iron-manganese	iron
Penobscot black shale	Northeast	Maine	Marine chemocline	Black shale	copper; gold; molybdenum; petroleum; stone coal; uranium
Heath Formation— Cox Ranch Member	Northwest	Montana	Marine chemocline	Black shale	copper; molybdenum; petroleum; stone coal; uranium
Phosphoria Formation	Rocky Mountains	Colorado; Idaho; Montana; Nevada; Utah; Wyoming	Marine chemocline	Black shale; Phosphate	copper; gold; molybdenum; petroleum; phosphate fertilizer; stone coal; uranium
Batesville cobalt-manganese District	South Central	Arkansas	Marine chemocline	Iron-manganese	iron
Fayetteville Shale; Upper Mississippian (Serpukhovian) Phosphate	South Central	Arkansas; Missouri; Oklahoma	Marine chemocline	Phosphate	phosphate fertilizer; uranium
Pennsylvanian Phosphate, Black Shale, Underclay	South Central	Alabama; Arkansas; Georgia; Illinois; Indiana; Iowa; Kansas; Kentucky; Maryland; Michigan; Missouri; Nebraska; New York; Ohio; Oklahoma; Pennsylvania; Tennessee; Texas; Virginia; West Virginia	Marine chemocline	Black shale; Phosphate	copper; gold; molybdenum; petroleum; phosphate fertilizer; stone coal; uranium
Upper Devonian Phosphate	South Central	Alabama; Arkansas; Georgia; Illinois; Indiana; Iowa; Kentucky; Maryland; Michigan; Mississippi; Missouri; Ohio; Oklahoma; Pennsylvania; Tennessee; Virginia; West Virginia	Marine chemocline	Black shale; Iron-manganese; Phosphate	copper; gold; iron; molybdenum; petroleum; phosphate fertilizer; stone coal; uranium
Middle Devonian REE phosphates	Southeast	West Virginia	Marine chemocline	Phosphate	phosphate; uranium
Miocene-Pliocene phosphate strata	Southeast	Florida; Georgia; Maryland; North Carolina; South Carolina; Virginia	Marine chemocline	Phosphate	phosphate; uranium
Gibellini and Carlin Vanadium	Southwest	Nevada	Marine chemocline	Black shale	copper; gold; molybdenum; petroleum; stone coal; uranium
Lower Mississippian (Osagean-Meramecian) Phosphate	Southwest	Utah	Marine chemocline	Phosphate	phosphate fertilizer; uranium
Middle-Late Miocene Phosphate	Southwest	California	Marine chemocline	Phosphate	phosphate; uranium
Three Kids district	Southwest	Nevada	Marine chemocline	Iron-manganese	iron