Chapter 25: The Sukhoi Log Gold Deposit, Russia

2020 ◽  
pp. 523-543
Author(s):  
G. L. Vursiy ◽  
I. A. Zibrov ◽  
S. G. Lobov ◽  
A. S. Yakubchuk
Keyword(s):  
Gold Deposit ◽  
Black Shale ◽  
Black Shales ◽  
Passive Margin ◽  
Early Paleozoic ◽  
Sedimentary Sequences ◽  
Isotopic Studies ◽  
Regional Tectonic ◽  
Thrust Zone ◽  
Tectonic Features

Abstract Sukhoi Log, Russia’s largest gold deposit, containing 1,960 metric tons (t) of gold within the deformed Neoproterozoic sedimentary sequences of the Patom passive margin, can be classified as an orogenic gold system. This giant and nearby smaller deposits occur in black shale horizons at several stratigraphic levels. The understanding of Sukhoi Log evolved from a small quartz vein occurrence to a large disseminated gold resource. The genesis of the deposit, originally considered to be related to a granitic intrusion, was later reinterpreted as metamorphogenic, with a significant contribution of synsedimentary gold in pyrite. Recent isotopic studies showed that there may have been more than one early Paleozoic synmetamorphic gold-mineralizing event, so the deposit most likely has a multistage origin. Black shales might have acted either as a synsedimentary and/or synmetamorphic geochemical trap for auriferous fluids. Structurally, the mineralization is confined to the axial portion of the recumbent Sukhoi Log anticline, conjugate with the Kadali-Sukhoi Log shear zone. This imbricate thrust zone marks a major boundary between the Chuya-Nechera anticlinorium and Bodaibo synclinorium, two regional tectonic features in the Patom Highlands.

scholarly journals Impact of Paleosalinity, Paleoredox, Paleoproductivity/Preservation on the Organic Matter Enrichment in Black Shales from Triassic Turbidites of Semanggol Basin, Peninsular Malaysia

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 915
Author(s):  
Zulqarnain Sajid ◽  
Mohd Ismail ◽  
Muhammad Zakariah ◽  
Haylay Tsegab ◽  
José Gámez Vintaned ◽  
...  
Keyword(s):  
Organic Matter ◽  
Black Shale ◽  
Distal Part ◽  
Peninsular Malaysia ◽  
Black Shales ◽  
Passive Margin ◽  
Geochemical Data ◽  
Northwestern Part ◽  
Submarine Fan ◽  
Rock Eval

Turbidite-associated black shale of the Semanggol Formation is extensively distributed in the northwestern part of the Western Belt, Peninsular Malaysia. The black shale occurs as a dark grey to black and thick to medium-bedded deposit. It represents the distal part of submarine fan system (outer-fan) overlying interbedded sandstone to shale facies of the mid-fan and conglomeratic pebbly sandstone facies of the inner-fan. Field observations and its widespread occurrence have resulted in the black shale being considered as a potential analog for a source rock in offshore Peninsular Malaysia. The present study includes detailed mineralogical (XRD, SEM, and EDX analysis), inorganic geochemical (major oxides, trace elements TEs, and rare earth elements REEs), and Rock-Eval pyrolysis analyses of the black shale samples, collected from the Gunung Semanggol, Bukit Merah, and Nami areas in northwestern Peninsular Malaysia. The primary focus of this study is to investigate the provenance, paleoredox conditions, paleoclimate, sedimentary rate, paleoproductivity, and upwelling system that would be helpful to understanding the role of these parameters in the enrichment of organic matter (OM) in the black shale. The Rock-Eval analysis shows that the black shale of the Semanggol Formation comprises type-III kerogens, which suggests organic input from a terrestrial source. The black shale also contains mature to postmature organic matter. Based on the mineralogical analysis, the mineral composition of the black shale comprises illite and kaolinite, with abundant traces of quartz and feldspar as well as few traces of titanium and zircon. Inorganic geochemical data designate black shale deposition in a passive margin setting that has experienced moderate to strong weathering, semi-arid to hot arid climate, and moderate sedimentation rate. Ratios of Ni/Co, U/Th, and V/(V+Ni) along with slightly negative to positive Ce* anomalies and UEF-MoEF cross-plot unanimously indicate anoxic/dysoxic water conditions that are suitable for organic matter preservation. Geochemical proxies related to modern upwelling settings (i.e., Cd/Mo, Co vs. Mn) show that the deep marine black shale was strongly influenced by persistent upwelling, a first-order controlling factor for organic matter enrichment in the distal part (outer fan of the submarine fan system) of the Semanggol Basin. However, productivity-controlled upwelling and a high sedimentary rate, as well as high-productivity in oxygen-depleted settings without strong anoxic conditions, has played an essential role in the accumulation of organic matter.

Evolution of the early Paleozoic Cordilleran margin of Laurentia: tectonic and eustatic events interpreted from sequence stratigraphy and conodont community patterns

2005 ◽  
Vol 42 (6) ◽  
pp. 999-1031 ◽  
Author(s):  
Shunxin Zhang ◽  
Leanne J Pyle ◽  
Christopher R Barnes
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Passive Margin ◽  
Early Paleozoic ◽  
Relative Sea Level ◽  
Lower Paleozoic ◽  
Community Patterns ◽  
Regional Tectonic ◽  
Laurentian Margin ◽  
Cordilleran Margin

Several field seasons in the Canadian Cordillera have allowed the measurement, description and sampling of over 20 000 m of lower Paleozoic strata from 26 stratigraphic sections across four platform-to-basin transects, with the recovery of over 100 000 conodonts from more than 1200 4–5 kg samples. This work was part of the Lithoprobe Slave – Northern Cordillera Lithospheric Evolution (SNORCLE) project but is also being extended through a Pan-Lithoprobe project to understand the tectonic and eustatic response of much of the Laurentian plate through the early Paleozoic. Based on the abundant field data, the complex stratigraphic framework is interpreted in terms of sequence stratigraphy and a derived relative sea-level curve. Using detailed conodont taxonomic and biostratigraphic results, cluster analysis of conodont distributional data identified an evolving series of conodont communities through space and time. These communities were partitioned across the platform-to-basin gradient and provide an additional sensitive indicator of relative sea-level change. These two independent approaches generated comparable eustatic curves for this Cordilleran Laurentian margin during much of the early Paleozoic and identified some global eustatic events noted by earlier workers. This part of Laurentia was not a simple passive margin during the early Paleozoic, but rather was affected by four main tectonic events complicated by six principal eustatic changes. Some success was achieved in filtering the global and regional tectonic–eustatic effects and in proposing causes for some of the events.

Siratur gold deposit in the black shales of the ophiolite association (the Southern Urals)

2020 ◽  
pp. 64-70
Author(s):  
A. V. Snachev ◽  
F. F. Latypov ◽  
V. I. Snachev ◽  
M. A. Rassomakhin ◽  
D. G. Koshchug ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Black Shale ◽  
Southern Urals ◽  
Black Shales ◽  
Chemical Characteristics ◽  
The Southern Urals ◽  
Gold Ore ◽  
Ocean Ridges ◽  
Ore Mineralization ◽  
Gold Sulfide

The Siratur gold deposit is located in the northern part of the South Ural segment of the Main Ural Fault. Its ore zone is confined to the area of the tectonic junction of the serpentinite of the Nurali massif and the submeridional strip of carbonaceous schists of the Ordovician Polyakovka Formation. Its composition is widely represented basalts with chemical characteristics of the main effusive rocks of the mid-ocean ridges. In the black shale deposits of the Siratur deposit, gold ore mineralization is mainly represented by the gold-sulfide vein-disseminated type, and in the listwanite-beresite complex, gold-quartz-low-sulfide vein-streaked type. Microprobe studies of zolotins showed that gold in ores of the first type has a low-qality of 670–820, and in the second — 940–970. The deposit can be attributed to the polygenic and polychronous type.

scholarly journals Early Paleozoic rifting and reactivation of a passive-margin rift: Insights from detrital zircon provenance signatures of the Potsdam Group, Ottawa graben: Comment

2019 ◽  
Vol 131 (3-4) ◽  
pp. 695-698
Author(s):  
Ed Landing ◽  
Osman Salad Hersi ◽  
Lisa Amati ◽  
Stephen R. Westrop ◽  
David A. Franzi
Keyword(s):  
Detrital Zircon ◽  
Passive Margin ◽  
Early Paleozoic

scholarly journals Erratum to “A Perspective on Stratigraphic, Vertically-Upward “Displacements or Dislocations” of Conodont-Elements: An Example From the Upper Devonian, Pre-Lithified, Black Shales of the Chattanooga Shale Formation In Tennessee, USA” ...

2019 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Michael Iannicelli
Keyword(s):  
Black Shale ◽  
Environmental Chemistry ◽  
Black Shales ◽  
Photic Zone ◽  
Marine Organic Matter ◽  
Chattanooga Shale ◽  
Shale Formation ◽  
Organic Matter Biomarkers ◽  
Reference Section ◽  
Made In

Even though the author already incorporated the citation of Sinninghe-Damste & Schouten (2006) into the text of the paper, the author regrets having failed to include their full citation within the Reference Section of my above paper which is: Sinninghe-Damste, J. S. & Schouton, S. (2006). Biological markers for anoxia in the photic zone of the water column. In, Volkman, J. K. (ed.), Marine Organic Matter: Biomarkers, Isotopes and DNA, (pp. 127 – 163). The Handbook of Environmental Chemistry, vol. 2N. Springer: Berlin and Heidelberg. https://doi.org/10.1007/698_2_005 The author also needs to paraphrase a statement made in the last three lines of the 2nd paragraph on page 40 where it reads as: “Thus, we may conclude here that paleo-upfreezing of any conodont-element(s) originally buried in the pre-lithified, light-colored shale occurred in order to account for their presence in black shale”. Instead, in lieu of that statement, it should read as “At this point in time of the study, we may tentatively conclude here while completely concluding later in the study, that conodont-elements originally existing in the underlying, pre-lithified, light-colored shale, had to paleo-upfreeze vertically upward into pre-lithified, black shale sediment in order to account for their presence in lithified black shale”.

The initiation of the early Paleozoic Cordilleran miogeocline: evidence from the uppermost Proterozoic – Lower Cambrian Hamill Group of southeastern British Columbia

1988 ◽  
Vol 25 (1) ◽  
pp. 1-19 ◽  
Author(s):  
William J. Devlin ◽  
Gerard C. Bond
Keyword(s):  
British Columbia ◽  
Lower Cambrian ◽  
Direct Evidence ◽  
Thermal Anomaly ◽  
Passive Margin ◽  
Early Paleozoic ◽  
Upper Proterozoic ◽  
Windermere Supergroup ◽  
Depositional Setting ◽  
Thermal Subsidence

The uppermost Proterozoic–Lower Cambrian Hamill Group of southeastern British Columbia contains geologic evidence for a phase of extensional tectonism that led directly to the onset of thermally controlled subsidence in the Cordilleran miogeocline. Moreover, the Hamill Group contains the sedimentological record of the passage of the ancient passive margin from unstable tectonic conditions associated with rifting and (or) the earliest phases of thermal subsidence to post-rift conditions characterized by stabilization of the margin and dissipation of the thermal anomaly generated during the rift phase (the rift to post-rift transition). Widespread uplift that occurred prior to and during the deposition of the lower Hamill Group is indicated by an unconformable relation with the underlying Windermere Supergroup and by stratigraphic relations between Middle and Upper Proterozoic strata and unconformably overlying upper Lower Cambrian quartz arenites (upper Hamill Group) in the southern borderlands of the Hamill basin. In addition, the coarse grain size, the feldspar content, the depositional setting, and the inferred provenance of the lower Hamill Group are all indicative of the activation of basement sources along the margins of the Hamill basin. Geologic relations within the Hamill Group that provide direct evidence for extensional tectonism include the occurrence of thick sequences of mafic metavolcanics and rapid vertical facies changes that are suggestive of syndepositional tectonism.Evidence of extensional tectonism in the Hamill Group directly supports inferences derived from tectonic subsidence analyses that indicate the rift phase that immediately preceded early Paleozoic post-rift cooling could not have occurred more than 10–20 Ma prior to 575 ± 25 Ma. These data, together with recently reported isotopic data that suggest deposition of the Windermere Supergroup began ~730–770 Ma, indicate that the rift-like deposits of the Windermere Supergroup are too old to represent the rifting that led directly to the deposition of the Cambro-Ordovician post-rift strata. Instead, Windermere sedimentation was apparently initiated by an earlier rift event, probably of regional extent, that was part of a protracted, episodic rift history that culminated with continental breakup in the latest Proterozoic – Early Cambrian.

Volcanism on the passive margin of Laurentia: an early Paleozoic analogue of Cretaceous volcanism on the northeastern American margin: Reply

1990 ◽  
Vol 27 (11) ◽  
pp. 1552-1554 ◽  
Author(s):  
Stephen Kumarapeli ◽  
Karen St. Seymour ◽  
Hillar Pintson ◽  
Elizabeth Hasselgren
Keyword(s):  
Passive Margin ◽  
Early Paleozoic ◽  
Cretaceous Volcanism

Accumulation Conditions and Gas Content Characteristics of the Lower Silurian in Northwestern Hunan, China

2013 ◽  
Vol 868 ◽  
pp. 192-195
Author(s):  
Tuo Lin ◽  
Jin Chuan Zhang ◽  
Bo Li ◽  
Wei He ◽  
Xuan Tang
Keyword(s):  
Black Shale ◽  
Sedimentary Environment ◽  
Sedimentary Facies ◽  
Black Shales ◽  
Gas Content ◽  
Burial Depth ◽  
Reservoir Properties ◽  
Isothermal Adsorption ◽  
Lower Silurian ◽  
Deposition Conditions

The Lower Silurian marine shale is widely distributed in Northwestern Hunan and features in a large thickness of dark shale showed at outcrops. However, the accumulation conditions and gas content is unknown. The sedimentary facies, thickness and distribution, organic matter types and content, maturity, reservoir properties and gas content of the Lower Silurian black shale in Northwestern Hunan were investigated by field observation, sampling and experimental analysis. The results show that the black shales sedimentary environment is deep water continental shelf, with featured in abundant fossil. The burial depth of the Lower Silurian black shale is 0-3000 m, and its thickness is 10-40m while the average TOC is 1.0% and average Ro is 2.9%. For the disadvantaged sedimentary facies and shallow depth, the maximum gas content of the Lower Silurian black shale from well site desorption test is 0.59m3/t only, but the result of isothermal adsorption simulate test show that the Lower Silurian black shale have a good adsorption capacity, and can generate a large number of shale gas in Northwestern Hunan where better deposition conditions and suitable depth exist in.

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