SULFUR PROXIES IN TYPE III BLACK SHALES: Fe, Mn, Co, Cu, Ni, Zn, Sc Pat WILDE Pangloss Foundation, 1735 Highland Place; Berkeley, CA Mary S. QUINBY-HUNT Lawrence Berkeley Laboratory: Berkeley, CA Timothy W. LYONS Department of Earth Sciences, University of California-Riverside: Riverside, CA

Why Calculate Proxies for C, S, P etc. ? Data enhancement for old data sets Data enhancement for old data sets Provide for elements not analyzed Provide for elements not analyzed Useful for assessing initial reservoir conditions disguised by diagenesis and elemental transfer through geologic time Useful for assessing initial reservoir conditions disguised by diagenesis and elemental transfer through geologic time Data recovery when originals not available Data recovery when originals not available

Black Shale Groups > 50,000 ppm Al, < 4000 ppm Ca Group 1 Oxic Group 2 Mn- Soluble Group 3 Mn,Fe- Soluble Group 4 V-High Mn > 830Mn < 730 Mn < 230 Fe > 38500Fe < V < 320 V > 320

Sulfur proxies using Fe, Ni, Co, and Cu Determined with 62 Type-III Black Shales 1 from Modern Cariaco Basin 2 and Devonian of New York 3 Proxies developed for ODP [Cariaco] site 2 used to estimate unreported S for Cariaco Basin USGS core PL07-39C 4 located about 50 km E Corresponding lithologic units and ages were compared. Estimated values internally agreed within a range of 0.4 % Sulfur. 1.Quinby-Hunt and Wilde, 1991, Lyons et al.., Werne et al., Piper and Dean, 2002

Sulfur proxies using Fe, Ni, Co, and Cu High correlation over ~400 million years → Sulfur-Metal relationships relatively fixed during deposition and early diagenesis. Additional sulfur proxies with Mn, Sc and Zn, found in Cariaco Basin, but could not be reproduced for the Devonian samples.

Type III Black Shale Proxies Composite 62 samples Pyrite Sulfur % = (Fe ppm) Fe R square = 0.92 R square = 0.92 Pyrite Sulfur % = (Ni ppm) Ni R square = 0.88 R square = 0.88 Pyrite Sulfur % = 0.118(Co ppm) Co R square = 0.85 R square = 0.85 Pyrite Sulfur % = (Cu ppm) Cu R square = 0.68 R square = 0.68

Cariaco Basin + New York Oatka Fm Fe

Cariaco Basin + New York Oakta Fm Ni

Cariaco Basin + New York Oatka Fm Co

Cu

Reverse correlation S py vs Mn Cariaco Basin vs NY Devonian

Trends in Oxygen, CO2, Sulfate and Phosphate over Time After COPSE model (Bergman et al., p

Evidence of Oceanic Ventilation?? Middle Devonian Oatka Creek Formation Middle Devonian Oatka Creek Formation Deposited during rise in atmospheric O 2 and development of land plants Deposited during rise in atmospheric O 2 and development of land plants Atmospheric CO2 is reduced by production of O2 thereby lowering  CO2 concentration in seawater Atmospheric CO2 is reduced by production of O2 thereby lowering  CO2 concentration in seawater [ Sulfate] in seawater also increased [ Sulfate] in seawater also increased

Evidence of Oceanic Ventilation?? Decrease of Mn with increased S suggests [prior to mid- Devonian] Decrease of Mn with increased S suggests [prior to mid- Devonian] MnCO3 deposition under anoxic conditions MnCO3 deposition under anoxic conditions Fe sulfide deposition under anoxic conditions Fe sulfide deposition under anoxic conditions Lowering of  CO2 + increased oxygenation in mid-Devonian seawater → Lowering of  CO2 + increased oxygenation in mid-Devonian seawater → Destabilization of MnCO 3 → Mn ++ Destabilization of MnCO 3 → Mn ++

Mn and Fe Redox Zones – with Rhodochrosite

Evidence of Oceanic Ventilation?? Accordingly Accordingly MnCO3 ‘ dissolved ’ into Mn 2+ returned to the water column MnCO3 ‘ dissolved ’ into Mn 2+ returned to the water column Thus Mn decreases as Pyritic S increases. Thus Mn decreases as Pyritic S increases. Sulfate reduction continues with Fe present to form additional pyrite Sulfate reduction continues with Fe present to form additional pyrite

New York Oatka Fm - Devonian As

Cariaco Basin - Zones I & II Sc

Zn

Sulfur proxies using Fe, Ni, Co, and Cu Determined with 51 Type-III Black Shales 1 from Modern Cariaco Basin 2 and Devonian of New York 3 Proxies developed for ODP [Cariaco] site 2 used to estimate unreported S for Cariaco Basin USGS core PL07-39C 4 located about 50 km E Estimated values internally agreed within a range of 0.4 % Sulfur. 1.Quinby-Hunt and Wilde, 1991, Lyons et al.., Werne et al., Piper and Dean, 2002

Sample Sites in Cariaco Basin ODP: Lyons et al. (2003) PLO7: Piper and Dean (2002)

Sulfur Proxy by Metals Cariaco Basin Comparisons

Sulfur proxies using Fe, Ni, Co, and Cu Extrapolation of sulfur proxies using Mn, Sc, and Zn over long time spans should be used with caution. Variations among proxies with time might be used to track various sedimentary and mineralogical processes. More data sets of varying ages, but with similar lithologies and anoxic conditions, should be compared.

What does this all mean?? –Ray knew!!

Siever Diagram

 THANKS, RAY !!! For all the wonderful MEMORIES

SULFUR PROXIES IN TYPE III BLACK SHALES: Fe, Mn, Co, Cu, Ni, Zn, Sc Pat WILDE Pangloss Foundation, 1735 Highland Place; Berkeley, CA Mary S. QUINBY-HUNT Lawrence Berkeley Laboratory: Berkeley, CA Timothy W. LYONS Department of Earth Sciences, University of California-Riverside: Riverside, CA

References Piper, D. Z. and Dean, W. E., 2002, Trace-Element Deposition in the Cariaco Basin,Venezuela Shelf, under Sulfate-Reducing Conditions. A History of the Local Hydrography and Global Climate, 20 Ka to the Present: US Geological Survey Prof. Paper 670, Piper, D. Z. and Dean, W. E., 2002, Trace-Element Deposition in the Cariaco Basin,Venezuela Shelf, under Sulfate-Reducing Conditions. A History of the Local Hydrography and Global Climate, 20 Ka to the Present: US Geological Survey Prof. Paper 670, Quinby-Hunt. M. S. and P. Wilde, 1991, The provenance of low-calcic black shales: Mineralium Deposita, v. 26, p Quinby-Hunt. M. S. and P. Wilde, 1991, The provenance of low-calcic black shales: Mineralium Deposita, v. 26, p Quinby-Hunt, M. S. and Wilde, P., 1996, Depositional environments of calcic marine black shales: Economic Geology, vol. 91, p Quinby-Hunt, M. S. and Wilde, P., 1996, Depositional environments of calcic marine black shales: Economic Geology, vol. 91, p Werne, J. P., Sageman, B. B., Lyons, T. W. and Hollander, D. J., 2002, An integrated assessment of a "type euxinic" deposit: Evidence for multiple controls on black shale deposition in the Middle Devonian Oatka Creek Formation: American Journal of Science, v. 302, p Werne, J. P., Sageman, B. B., Lyons, T. W. and Hollander, D. J., 2002, An integrated assessment of a "type euxinic" deposit: Evidence for multiple controls on black shale deposition in the Middle Devonian Oatka Creek Formation: American Journal of Science, v. 302, p