Stratigraphic differentiation by sulfur isotopes between Upper Cambrian and Lower Devonian gypsum-bearing units, District of Mackenzie, N.W.T.

1977 ◽  
Vol 14 (12) ◽  
pp. 2790-2796 ◽  
Author(s):  
Robert O. van Everdingen ◽  
H. Roy Krouse
Keyword(s):  
Standard Deviation ◽  
Lower Devonian ◽  
Sulfur Isotope ◽  
Sulfur Isotopes ◽  
Lower Portion ◽  
Main Thrust ◽  
Upper Cambrian ◽  
Rock Formation ◽  
Rock Strata ◽  
Isotope Analyses

Sulfur isotope analyses of gypsum in outcrop and subsurface samples from the Lower Devonian Bear Rock Formation gave δ34S values ranging from + 10.3 to + 21.8‰ (mean + 16.1‰, standard deviation 2.85‰); samples from the Upper Cambrian Saline River Formation gave δ34S values ranging from + 24.7 to + 40.2‰ (mean + 30.3‰, standard deviation 3.65‰). The lower portion of one outcrop section of 532 ft (162.2 m) on the northeast side of the Norman Range (Franklin Mountains), mapped as Saline River Formation, showed anomalous δ34S values (+ 10.3–+ 18.7‰), suggesting correlation with the Bear Rock Formation. It is likely that at least 97 ft (29.6 m) of Bear Rock strata are present in this section, overlain by a maximum of 435 ft (132.6 m) of gypsiferous Saline River strata that form the base of the main thrust plate of the Norman Range in this locality.

34S and 18O abundances differentiate Upper Cambrian and Lower Devonian gypsum-bearing units, District of Mackenzie, N.W.T.—an update

1982 ◽  
Vol 19 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
Robert O. van Everdingen ◽  
M. Asif Shakur ◽  
H. Roy Krouse
Keyword(s):  
Lower Devonian ◽  
Sulfur Isotope ◽  
Thrust Fault ◽  
Upper Cambrian ◽  
Rock Formation ◽  
Opposite Trend ◽  
The Mean ◽  
Rock Strata ◽  
Sulfur Isotope Data ◽  
Isotope Analyses

Previous sulfur isotope data for the Lower Devonian Bear Rock Formation and the Upper Cambrian Saline River Formation in the District of Mackenzie, N.W.T. have been supplemented by additional sulfur isotope analyses as well as δ18O determinations on sulfates from outcrops, drill cuttings, and cores. Whereas the mean δ34S value for the Bear Rock Formation is lower than that of the Saline River Formation (+17.8 ± 1.8‰ versus +29.7 ± 2.2‰), the opposite trend was found for the mean δ18O values (+15.6 ± 1.0‰ versus +13.0 ± 1.5‰). The new data confirm that, for all samples analysed, there is no overlap between δ34S values for the two formations, while the δ18O data display some overlap. The earlier δ34S data for samples from an evaporitic section on the northeast side of the Norman Range (originally mapped as consisting entirely of Saline River Formation) indicated the presence of a thrust fault in the section, with Saline River strata overlying Bear Rock strata. The δ18O data for those samples, which fortuitously fall into two non-overlapping groups, confirm the earlier conclusions based on the δ34S data and allow us to define the position of the thrust-fault contact somewhat more closely.

Sulfur isotopes in diamonds reveal differences in continent construction

Science ◽  
2019 ◽  
Vol 364 (6438) ◽  
pp. 383-385 ◽  
Author(s):  
Karen V. Smit ◽  
Steven B. Shirey ◽  
Erik H. Hauri ◽  
Richard A. Stern
Keyword(s):  
Sulfur Isotope ◽  
Sulfur Isotopes ◽  
West African ◽  
Diamond Growth ◽  
Mantle Lithosphere ◽  
Continental Lithosphere ◽  
Slave Craton ◽  
Tectonic Processes ◽  
Isotope Record ◽  
Diamond Inclusions

Neoproterozoic West African diamonds contain sulfide inclusions with mass-independently fractionated (MIF) sulfur isotopes that trace Archean surficial signatures into the mantle. Two episodes of subduction are recorded in these West African sulfide inclusions: thickening of the continental lithosphere through horizontal processes around 3 billion years ago and reworking and diamond growth around 650 million years ago. We find that the sulfur isotope record in worldwide diamond inclusions is consistent with changes in tectonic processes that formed the continental lithosphere in the Archean. Slave craton diamonds that formed 3.5 billion years ago do not contain any MIF sulfur. Younger diamonds from the Kaapvaal, Zimbabwe, and West African cratons do contain MIF sulfur, which suggests craton construction by advective thickening of mantle lithosphere through conventional subduction-style horizontal tectonics.

Carbon, oxygen, and sulfur isotope compositions and model of the Silurian rock formation in northwestern Belarus

2018 ◽  
Vol 53 (1) ◽  
pp. 1-13 ◽  
Author(s):  
A. A. Makhnach ◽  
S. A. Kruchek ◽  
B. G. Pokrovsky ◽  
G. D. Strel’tsova ◽  
O. V. Murashko ◽  
...  
Keyword(s):  
Sulfur Isotope ◽  
Rock Formation

Isotope geochemistry of dissolved, precipitated, airborne, and fallout sulfur species associated with springs near Paige Mountain, Norman Range, N.W.T.

1982 ◽  
Vol 19 (7) ◽  
pp. 1395-1407 ◽  
Author(s):  
Robert O. van Everdingen ◽  
M. Asif Shakur ◽  
H. Roy Krouse
Keyword(s):  
Sulfate Reduction ◽  
Water Vapour ◽  
Carbonate Rocks ◽  
Isotope Fractionation ◽  
Lower Devonian ◽  
Isotope Geochemistry ◽  
Spring Water ◽  
Sulfate Radical ◽  
Sulfur Species ◽  
Rock Formation

δ34S values determined for dissolved sulfate in water discharged by sulfurous springs near Paige Mountain identify gypsum beds in the Lower Devonian Bear Rock Formation as the sulfate source, whereas relatively low δ18O values show that as much as 30% of the sulfate may have gone through a reduction–re-oxidation cycle. Reduced sulfur species in the spring water have negative δ34S values as a result of microbiological isotope fractionation during sulfate reduction; airborne sulfur species (H2S, SO2, H2SO4) and gypsum formed through reaction of H2SO4 fallout with exposed carbonate rocks show similar negative δ34S values. Negative δ18O values for the sulfate radical in H2SO4 fallout and in the alteration product indicate that more than half of the oxygen reacting with airborne H2S is derived from water vapour.

scholarly journals Environmental insights from high-resolution (SIMS) sulfur isotope analyses of sulfides in Proterozoic microbialites with diverse mat textures

Geobiology ◽  
2017 ◽  
Vol 16 (1) ◽  
pp. 17-34 ◽  
Author(s):  
M. L. Gomes ◽  
D. A. Fike ◽  
K. D. Bergmann ◽  
C. Jones ◽  
A. H. Knoll
Keyword(s):  
High Resolution ◽  
Sulfur Isotope ◽  
Isotope Analyses

Oxygen- and sulfur-isotope geochemistry of acidic groundwater discharge in British Columbia, Yukon, and District of Mackenzie, Canada

1985 ◽  
Vol 22 (11) ◽  
pp. 1689-1695 ◽  
Author(s):  
Robert O. van Everdingen ◽  
M. Asif Shakur ◽  
Frederick A. Michel
Keyword(s):  
British Columbia ◽  
Sulfur Isotope ◽  
Thiobacillus Ferrooxidans ◽  
Isotope Geochemistry ◽  
Black Shales ◽  
Metal Sulfides ◽  
Sulfide Mineralization ◽  
Middle Cambrian ◽  
Acidic Groundwater ◽  
Isotope Analyses

The Paint Pots in Kootenay National Park (British Columbia) appear to derive the Fe, Zn, Pb, and [Formula: see text] contents of their water from sulfide mineralization in Lower and Middle Cambrian carbonates. The Fe, Zn, Ni, and [Formula: see text] contents of groundwater discharging into a tributary of Engineer Creek (Yukon) are likely derived from sulfide mineralization in Devonian or Ordovician black shales exposed in the area. The high Fe and [Formula: see text] contents of a natrojarosite deposit northeast of Fort Norman (Northwest Territories) are probably derived from pyritiferous Cretaceous shales in that area. Isotope analyses of water and of dissolved and precipitated sulfur species from these three sites where acidic, heavy-metal-bearing groundwater is being discharged revealed that between 38 and 74% of the oxygen used in the subsurface oxidation of metal sulfides is supplied by H2O molecules rather than by molecular (dissolved) oxygen. The available data also suggest that lower percentages of water oxygen in the secondary sulfates reflect increasing activity of Thiobacillus ferrooxidans or similar bacteria in the oxidation process.

Lead Isotope Studies of Rock Samples from the Superior Geological Province

1971 ◽  
Vol 8 (4) ◽  
pp. 444-454 ◽  
Author(s):  
J. M. Ozard ◽  
R. D. Russell
Keyword(s):  
Standard Deviation ◽  
Lead Isotope ◽  
Lead Isotopes ◽  
Internal Standard ◽  
Lake Area ◽  
Single Filament ◽  
Lead Isotope Ratios ◽  
Rock Samples ◽  
Isotope Studies ◽  
Isotope Analyses

Single filament whole rock lead isotope analyses were corrected for fractionation by using an internal standard (double spike). An estimated standard deviation of 0.15% was obtained for lead isotope ratios and 0.25% for lead and uranium concentrations. These are some of the first analyses of this accuracy for lead isotopes in whole rocks. Lead and uranium analyses from the Vogt–Hobbs area near Lake Timagami, Ontario and from the Rice Lake – Beresford Lake area, Manitoba gave ages with the pattern lead–lead age > uranium 235 – lead 207 age > uranium 238 – lead 206 age. This pattern was interpreted as arising from loss of lead from the systems studied. A similar three-stage history, marked by major events prior to 3000 m.y. ago and at approximately 2600 m.y. ago, fits both of these suites. This history is shown to be consistent with rubidium–strontium data, zircon uranium–lead ages, potassium–argon, and ore lead data.

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