Embed Size (px)
Citation preview
SULFUR PROXIES IN TYPE III BLACK SHALES:
Fe, Mn, Co, Cu, Ni, Zn, Sc
Pat WILDE Pangloss Foundation,
1735 Highland Place; Berkeley, CA 94709 [email protected]
Mary S. QUINBY-HUNT Lawrence Berkeley Laboratory: Berkeley, CA 94720
Timothy W. LYONS Department of Earth Sciences,
University of California-Riverside: Riverside, CA 92521-0423 [email protected]
Why Calculate Proxies for C, S, P Why Calculate Proxies for C, S, P etc.etc.??
Data enhancement for old data setsData enhancement for old data sets
Provide for elements not analyzedProvide for elements not analyzed
Useful for assessing initial reservoir conditions Useful for assessing initial reservoir conditions disguised by diagenesis and elemental transfer disguised by diagenesis and elemental transfer through geologic timethrough geologic time
Data recovery when originals not availableData recovery when originals not available
Black Shale Groups> 50,000 ppm Al, < 4000 ppm Ca
Group 1 Oxic
Group 2 Mn-
Soluble
Group 3Mn,Fe-
Soluble
Group 4V-High
Mn > 830 Mn < 730 Mn < 730 Mn < 230
Fe > 38500 Fe < 37500 Fe < 37500 Fe < 37500
V < 320 V < 320 V < 320 V > 320
Sulfur proxies using Fe, Ni, Co, and Cu Sulfur proxies using Fe, Ni, Co, and Cu
Determined with 62 Type-III Black Shales1 from
Modern Cariaco Basin2 and Devonian of New York3
Proxies developed for ODP [Cariaco] site2 used to estimate unreported S for Cariaco Basin USGS core PL07-39C4 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, 1996 2. Lyons et al.., 2003 3. Werne et al., 2002 4. Piper and Dean, 2002
Sulfur proxies using Fe, Ni, Co, and CuSulfur 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 ProxiesType III Black Shale ProxiesComposite 62 samplesComposite 62 samples
Pyrite Pyrite SulfurSulfur % = 0.000105( % = 0.000105(FeFe ppm) - 1.67 ppm) - 1.67 R square = R square = 0.920.92
Pyrite Pyrite SulfurSulfur % = 0.0179( % = 0.0179(NiNi ppm) + 0.339 ppm) + 0.339 R square = R square = 0.880.88
Pyrite Pyrite SulfurSulfur % = 0.118( % = 0.118(CoCo ppm) + .0967 ppm) + .0967 R square = R square = 0.850.85
Pyrite Pyrite SulfurSulfur % = 0.0172( % = 0.0172(CuCu ppm) + 0.877 ppm) + 0.877 R square = R square = 0.680.68
Cariaco Basin + New York Oatka Fm
Pyrite Sulfur % = 9E-05 (Fe ppm) - 1.1004
R2 = 0.8757 n = 62
0
1
2
3
4
5
6
7
0 10000 20000 30000 40000 50000 60000 70000
Fe ppm
Pyr
ite
Su
lfu
r %
FeFe
Cariaco Basin + New York Oakta Fm
Pyrite Sulfur % = 0.0174(Ni ppm) + 0.4026
R2 = 0.8684 n = 62
0
1
2
3
4
5
6
7
0 50 100 150 200 250 300 350 400
Ni ppm
Pyr
ite
Su
lfu
r %
NiNi
Cariaco Basin + New York Oatka Fm
Pyrite Sulfur % = 0.1169(Co ppm) + 0.0807
R2 = 0.8359 n= 62
0
1
2
3
4
5
6
7
0 10 20 30 40 50 60
Co ppm
Pyr
ite
Su
lfu
r %
CoCo
Cariaco Basin + New York Oatka Fm
Pyrite Sulfur % = 0.0168(Cu ppm) + 0.8088
R2 = 0.6552 n = 62
0
1
2
3
4
5
6
7
0 50 100 150 200 250 300
Cu ppm
Pyr
ite S
ulfu
r %
CuCu
Reverse correlation SReverse correlation Spypy vs Mn vs Mn Cariaco Basin vs NY Devonian Cariaco Basin vs NY Devonian Reverse correlation Spy Reverse correlation Spy vsvs MnMn
CariacoCariaco Trench Trench vsvs NY DevonianNY Devonian
Pyrite Sulfur % = 0.005(Mn ppm) + 0.3711
R2 = 0.7992 n = 30 CB
Pyrite Sulfur % = -0.0414 (Mn ppm) + 10.005
R2 = 0.6406 n = 21 Oatka Fm Devonian
0
1
2
3
4
5
6
7
100 150 200 250 300 350 400 450
Mn ppm
Pyr
ite S
ulfu
r %
Trends in Oxygen, CO2, Sulfate and Phosphate over Time
After COPSE model (Bergman et al., p. 418 2004
Evidence of Oceanic Ventilation??Evidence of Oceanic Ventilation??
Middle Devonian Oatka Creek FormationMiddle Devonian Oatka Creek Formation
Deposited during Deposited during rise in atmospheric Orise in atmospheric O22 and and development of land plantsdevelopment of land plants
Atmospheric CO2 is reduced by production of O2 Atmospheric CO2 is reduced by production of O2
thereby thereby lowering lowering CO2 concentration in seawaterCO2 concentration in seawater
[[Sulfate] in seawater Sulfate] in seawater also also increased increased
Evidence of Oceanic Ventilation??Evidence of Oceanic Ventilation??
Decrease of MnDecrease of Mn with with increased Sincreased S suggests [prior to mid- suggests [prior to mid-Devonian]Devonian]
MnCO3 MnCO3 deposition under anoxic conditions deposition under anoxic conditions Fe sulfideFe sulfide deposition under anoxic conditions deposition under anoxic conditions Lowering of Lowering of CO2CO2 ++ increased oxygenationincreased oxygenation in in
mid-Devonian seawater mid-Devonian seawater →→ Destabilization of MnCODestabilization of MnCO3 3 → Mn→ Mn++++
Mn and Fe Redox Zones – with Rhodochrosite
Evidence of Oceanic Ventilation??Evidence of Oceanic Ventilation??
AccordinglyAccordingly
MnCO3 ‘dissolved’ into MnMnCO3 ‘dissolved’ into Mn2+2+ returned to the returned to the water columnwater column
Thus Mn decreases as Pyritic S increases.Thus Mn decreases as Pyritic S increases.
Sulfate reduction continues with Fe present Sulfate reduction continues with Fe present to form additional pyriteto form additional pyrite
New York Oatka Fm - Devonian
Pyrite Sulfur % = 0.0856(As ppm) - 0.2642
R2 = 0.8621 n = 29
0
1
2
3
4
5
6
7
0 10 20 30 40 50 60 70 80
As ppm
Py
rite
Su
lfu
r %
AsAs
Cariaco Basin - Zones I & IIScSc
Pyrite Sulfur % = 0.1647 (Sc ppm) - 0.4607
R2 = 0.8958 n =32
0
0.5
1
1.5
2
2.5
3
3.5
5 7 9 11 13 15 17 19
Sc ppm
Pyr
ite S
ulfu
r %
Cariaco Basin - Zones I & IIZnZn
Pyrite Sulfur % = 0.0139 (Zn ppm) + 0.0484
R2 = 0.8654 n = 34
0
0.5
1
1.5
2
2.5
3
3.5
50 70 90 110 130 150 170 190 210
Zn ppm
Pyr
ite S
%
Sulfur proxies using Fe, Ni, Co, and Cu Sulfur proxies using Fe, Ni, Co, and Cu Determined with 51 Type-III Black Shales1 from
Modern Cariaco Basin2 and Devonian of New York3
Proxies developed for ODP [Cariaco] site2 used to estimate unreported S for Cariaco Basin USGS core PL07-39C4 located about 50 km E
Estimated values internally agreed within a range of 0.4 % Sulfur.
1.Quinby-Hunt and Wilde, 1991, 1996 2. Lyons et al.., 2003 3. Werne et al., 2002 4. Piper and Dean, 2002
Sample Sites in Cariaco BasinODP: Lyons et al. (2003) PLO7: Piper and Dean (2002)
Sulfur Proxy by MetalsCariaco Basin Comparisons
0
0.5
1
1.5
2
2.5
Depth 4 to 957 Cm: increasing to the right
Py
rite
Su
lfu
r %
via Fevia MnVia Covia Zn
via Cuvia Ni
Sulfur proxies using Fe, Ni, Co, and CuSulfur 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 beused 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 !!! THANKS, RAY !!! For all the wonderful For all the wonderful
MEMORIESMEMORIES
SULFUR PROXIES IN TYPE III BLACK SHALES:
Fe, Mn, Co, Cu, Ni, Zn, Sc
Pat WILDE Pangloss Foundation,
1735 Highland Place; Berkeley, CA 94709 [email protected]
Mary S. QUINBY-HUNT Lawrence Berkeley Laboratory: Berkeley, CA 94720
Timothy W. LYONS Department of Earth Sciences,
University of California-Riverside: Riverside, CA 92521-0423 [email protected]
ReferencesReferences
Piper, D. Z. and Dean, W. E. , 2002, Trace-Element Deposition in the Cariaco 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 Basin,Venezuela Shelf, under Sulfate-Reducing Conditions. A History of the Local Hydrography and Global Climate, 20 Ka to the Present: US Geological Local Hydrography and Global Climate, 20 Ka to the Present: US Geological Survey Prof. Paper 670, 1-41.Survey Prof. Paper 670, 1-41.
Quinby-Hunt. M. S. and P. Wilde, 1991, The provenance of low-calcic black Quinby-Hunt. M. S. and P. Wilde, 1991, The provenance of low-calcic black shales: Mineralium Deposita, v. 26, p. 113-121.shales: Mineralium Deposita, v. 26, p. 113-121.
Quinby-Hunt, M. S. and Wilde, P., 1996, Depositional environments of calcic Quinby-Hunt, M. S. and Wilde, P., 1996, Depositional environments of calcic marine black shales: Economic Geology, vol. 91, p. 4-13.marine black shales: Economic Geology, vol. 91, p. 4-13.
Werne, J. P., Sageman, B. B., Lyons, T. W. and Hollander, D. J., 2002, An 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 integrated assessment of a "type euxinic" deposit: Evidence for multiple controls on black shale deposition in the Middle Devonian Oatka Creek controls on black shale deposition in the Middle Devonian Oatka Creek Formation: American Journal of Science, v. 302, p. 110-143.Formation: American Journal of Science, v. 302, p. 110-143.
![Candide Socratic Seminar. Chapter 1 Discuss Pangloss’ philosophy. [p. 12, #2]](https://img.pdfslide.us/doc/110x75/56649e425503460f94b34fc8/candide-socratic-seminar-chapter-1-discuss-pangloss-philosophy-p-12.jpg)
