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euxinic environment

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Journal Article
Journal: AAPG Bulletin
Published: 01 May 1980
AAPG Bulletin (1980) 64 (5): 692.
...George E. Claypool; Joel S. Leventhal; Martin B. Goldhaber ABSTRACT The relation between organic carbon and sulfides in Devonian black shales can be used to identify these units as having been deposited in ancient marine euxinic environments. Based on the modern Black Sea analogy, the euxinic...
Journal Article
Journal: GSA Bulletin
Published: 01 June 1989
GSA Bulletin (1989) 101 (6): 774–782.
... of these elements, with a zero intercept characteristic of sediments deposited in a non-euxinic marine environment. Formation of diagenetic pyrite was carbon limited in these members. The Clegg Creek Member contains 10% to 15% TOC and 2% to 6% sulfide sulfur. Isotopic compositions of sulfide range from -5.0...
Journal Article
Published: 01 January 2001
Italian Journal of Geosciences (2001) 120 (2-3): 211–231.
... diatomitic and pelitic sequences of marine and euxinic environment; they are represented respectively by euxinic diatomitic clay and marl ("Tripoli Fm.") and by thin-bedded limestone, clay and marl, named "Torrente Calaggio" polychromatic argillites (Ciaranfi et alii, 1973). Three successions...
Journal Article
Published: 08 April 2015
Journal of the Geological Society (2015) 172 (3): 390–406.
... in turn may be reduced to even lighter H 2 S by subsequent bacterial sulphate reduction. Thus, pyrite and organic sulphur from euxinia are expected to have lighter sulphur isotopes than those from non-euxinic environments. Euxinic sediments have high FePy/FeHR ratios or high pyrite sulphur contents; thus...
FIGURES
First thumbnail for: Marine C, S and N biogeochemical processes in the ...
Second thumbnail for: Marine C, S and N biogeochemical processes in the ...
Third thumbnail for: Marine C, S and N biogeochemical processes in the ...
Journal Article
Journal: AAPG Bulletin
Published: 01 May 1955
AAPG Bulletin (1955) 39 (5): 575–629.
.... In northwestern North Dakota about 300 feet of dark-colored dense argillaceous limestone underlies the salt, indicating an euxinic depositional environment in this area prior to evaporite deposition. The Manitoba group is characterized by repetitive sequences of carbonate strata punctuated by thin persistent...
FIGURES
First thumbnail for: Devonian System of Williston Basin
Second thumbnail for: Devonian System of Williston Basin
Third thumbnail for: Devonian System of Williston Basin
Journal Article
Published: 01 October 2023
Russ. Geol. Geophys. (2023) 64 (10): 1196–1216.
... Eifelian (Malaya Salairka age) to aridic in the middle Givetian (Kerlegesh age). Basin sediments formed in the deep water oxic environments with good water aeration, excepting euxinic environments found in the lowermost part of studied succession. Middle Devonian lithology sedimentology geochemistry...
FIGURES
First thumbnail for: Lithology, Geochemistry of the Middle Devonian Sed...
Second thumbnail for: Lithology, Geochemistry of the Middle Devonian Sed...
Third thumbnail for: Lithology, Geochemistry of the Middle Devonian Sed...
Journal Article
Journal: Geology
Published: 01 December 1993
Geology (1993) 21 (12): 1091–1094.
...-enriched TRS in the deposits of ancient euxinic environments is commonly interpreted as evidence for early diagenetic sulfide formation where residual, less reactive iron phases were in contact with isotopically heavy dissolved sulfide (sulfate-depleted pore waters) for prolonged periods during burial...
Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 30 June 2021
Lithosphere (2021) 2021 (Special 1): 6684574.
..., which was ultimately responsible for depleted organic matter accumulation in the Niu-1 member. In the Niu-2 member, the anoxic-euxinic environment and high paleoproductivity, driven by continuous hydrothermal activity and rising sea level, were the main factors controlling the enrichment of organic...
FIGURES
First thumbnail for: Constraints on the Organic Matter Accumulation of ...
Second thumbnail for: Constraints on the Organic Matter Accumulation of ...
Third thumbnail for: Constraints on the Organic Matter Accumulation of ...
Image
Facies patterns of Riphean deposition in the southeastern part of the Yenisei Ridge in Late Shuntara – Early Seryi Klyuch time (the first stage of aggradation of the Seryi Klyuch carbonate platform, high stand). 1–7 – facies: 1 – basin plain with predominately hemipelagic carbonate-argillaceous sedimentation in euxinic environments, 2 – lower slope and basin plain with accumulation of various types of gravitites and hemipelagites in partially euxinic environments, 3 – upper slope with predominately intraclastic storm-related deposits, 4 – shelf edge with active formation of stromatolithic reefs, 5 – back-reef oolitic-intraclastic shoals, 6 – proximal lagoon-shelf environment with predominately stromatolithic mats, 7 – distal lagoon-shelf environment with predominately carbonate-argillaceous sediments; 8 – boundaries between facies (bergdashes show the direction of basin deepening); 9 – upper boundary of the oxygen zone.
Published: 01 July 1998
-argillaceous sedimentation in euxinic environments, 2 – lower slope and basin plain with accumulation of various types of gravitites and hemipelagites in partially euxinic environments, 3 – upper slope with predominately intraclastic storm-related deposits, 4 – shelf edge with active formation
Image
Schematic model for formation of pyrite associated with BSR process in euxinic environment.
Published: 10 October 2018
Figure 7. Schematic model for formation of pyrite associated with BSR process in euxinic environment.
Journal Article
Journal: Interpretation
Published: 10 October 2018
Interpretation (2018) 6 (4): SN71–SN83.
...Figure 7. Schematic model for formation of pyrite associated with BSR process in euxinic environment. ...
FIGURES
First thumbnail for: Sulfur isotope of pyrite response to redox chemist...
Second thumbnail for: Sulfur isotope of pyrite response to redox chemist...
Third thumbnail for: Sulfur isotope of pyrite response to redox chemist...
Journal Article
Journal: Geology
Published: 01 August 2006
Geology (2006) 34 (8): 617–620.
... signature of +1.6‰. We believe this value reflects Mo sulfide formation via diagenetic processes within sediments. Quantitative formation of Mo sulfide within the sulfidic water column of euxinic environments results in sediment isotope values similar to the modern seawater value (+2.3‰), as typified...
FIGURES
First thumbnail for: Authigenic molybdenum isotope signatures in marine...
Second thumbnail for: Authigenic molybdenum isotope signatures in marine...
Third thumbnail for: Authigenic molybdenum isotope signatures in marine...
Journal Article
Journal: AAPG Bulletin
Published: 01 June 1991
AAPG Bulletin (1991) 75 (6): 1007–1017.
...-bearing platy limestones, commonly cherty, as an associated coeval facies indicates the development of anoxic or euxinic environments, and the stromatolitic laminations in such rocks are attributed to the action of bacterial mats. It is suggested that an extensive column of deoxygenated water developed...
FIGURES
First thumbnail for: Impact of Cretaceous Sea Level Rise and Anoxic Eve...
Second thumbnail for: Impact of Cretaceous Sea Level Rise and Anoxic Eve...
Third thumbnail for: Impact of Cretaceous Sea Level Rise and Anoxic Eve...
Journal Article
Journal: Economic Geology
Published: 01 February 1984
Economic Geology (1984) 79 (1): 124–140.
... delta 34 S values of approximately -24 per mil indicating the presence of a euxinic environment. The delta 34 S values of fine-grained pyrite in the massive ore range from degrees 6.4 to + or -2.0 per mil; those of coarse-grained pyrite range from -3.5 to + or -5.5 per mil. A significant portion...
Journal Article
Journal: AAPG Bulletin
Published: 01 September 1970
AAPG Bulletin (1970) 54 (9): 1719–1745.
... black chert beds in member 2 formed as submarine slide deposits. The preservation of abundant organic material (3.7 percent organic carbon), including some petroleum, in some beds and the absence of bioturbation features indicated that sedimentation generally occurred in an euxinic environment...
FIGURES
First thumbnail for: Stratigraphy and Origin of Maravillas Formation (U...
Second thumbnail for: Stratigraphy and Origin of Maravillas Formation (U...
Third thumbnail for: Stratigraphy and Origin of Maravillas Formation (U...
... carbonate beds. Black sapropelic shales are interbedded with the salt beds. It appears that the euxinic environment in which the shales were deposited persisted during the deposition of salt. An understanding of the stratigraphy of the salt deposits has made possible a more complete depiction of early...
Image
Crossplots illustrating ash-enhanced euxinic condition in the Eagle Ford Group (Texas, USA). A: Mo content is greater in the Lower Eagle Ford Group (LEF) than in the other two units, indicating the LEF was deposited in euxinic environments. UEF—Upper Eagle Ford Group; Buda—Buda Formation. B: Cr increases as Al increases at low Al concentrations, but stays uniform as Al increases at high Al concentrations. The strong covariation of Mo/Al (in the LEF) with Fe/Al is shown in C, and with U/Al in D. AUCN—average upper crust normalized.
Published: 07 September 2018
Figure 3. Crossplots illustrating ash-enhanced euxinic condition in the Eagle Ford Group (Texas, USA). A: Mo content is greater in the Lower Eagle Ford Group (LEF) than in the other two units, indicating the LEF was deposited in euxinic environments. UEF—Upper Eagle Ford Group; Buda—Buda
Image
Molybdenum cycling in different redox settings. The relative concentrations of Mo and Mn increase from left to right in each profile and the dissolved Mo species in the bottom waters are shown along the top of each profile. a) Non-euxinic sediments with a manganous zone and no sulfidic zone. b) Non-euxinic sediments with both manganous and sulfidic zones. c) Non-euxinic sediments with a sulfidic zone and no manganous zone. d) Euxinic sediments where thiomolybdates are present in bottom waters. Examples of each category are from Baja California (Shimmield and Price 1986), Loch Etive, Scotland (Malcolm 1985), Santa Barbara, California basin (Poulson Brucker et al. 2009), Black Sea (Neubert et al. 2008), and the Cariaco Basin (Dean et al. 1999). The Mo concentration of average crustal rocks is shown. In non-euxinic environments, Mo concentrations in sediments are typically < 25 ppm (the crustal concentration and 25 ppm are shown as grey dashed lines). The heavy dashed line illustrates the higher Mo concentrations in Cariaco Basin euxinic sediments compared with the more restricted Black Sea. Modified from Scott and Lyons (2012).
Published: 01 January 2017
Etive, Scotland ( Malcolm 1985 ), Santa Barbara, California basin ( Poulson Brucker et al. 2009 ), Black Sea ( Neubert et al. 2008 ), and the Cariaco Basin ( Dean et al. 1999 ). The Mo concentration of average crustal rocks is shown. In non-euxinic environments, Mo concentrations in sediments
Image
Geochemical profiles of the San Jorge (a) and Tharsis (b) mines, including the redox state (redox), degree of pyritization (DOP), and K2O/Na2O and V/Cr ratios. The different redox environments are based on the Mn-Fe-V contents of the shale (cf. Quinby-Hunt and Wilde, 1984). DOP values above 0.65 are typical of euxinic environments, whereas those above 0.45 are characteristic of restricted settings (Raiswell et al., 1988). Geochemical data from Appendix 1.
Published: 01 January 2008
values above 0.65 are typical of euxinic environments, whereas those above 0.45 are characteristic of restricted settings ( Raiswell et al., 1988 ). Geochemical data from Appendix 1 .
Image
A simplified oceanic budget for Mo and its isotopes, showing the main inputs (rivers and hydrothermal) to and outputs (oxic and euxinic environments, plus upwellings) from the oceanic dissolved reservoir. The numbers below each source and sink are elemental fluxes in units of 108 moles y−1 and the isotopic composition of that flux, respectively. The δ98Mo is the 98Mo/95Mo ratio as expressed relative to a value of +0.25‰ for the molybdenum standard solution that is National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 3134. AfterKendall et al. (2017).
Published: 01 December 2018
Figure 3. A simplified oceanic budget for Mo and its isotopes, showing the main inputs (rivers and hydrothermal) to and outputs (oxic and euxinic environments, plus upwellings) from the oceanic dissolved reservoir. The numbers below each source and sink are elemental fluxes in units of 10 8