scholarly journals Using Mesoproterozoic sedimentary geochemistry to reconstruct basin tectonic geography and link organic carbon productivity to nutrient flux from a Northern Australian large igneous Province

2020 ◽  
Vol 32 (6) ◽  
pp. 1734-1750 ◽  
Author(s):  
Bo Yang ◽  
Alan S. Collins ◽  
Grant M. Cox ◽  
Amber J. M. Jarrett ◽  
Steven Denyszyn ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Nutrient Flux ◽  
Large Igneous Province ◽  
Sedimentary Geochemistry ◽  
Igneous Province ◽  
Carbon Productivity

scholarly journals Mercury Anomalies Link to Extensive Volcanism Across the Late Devonian Frasnian–Famennian Boundary in South China

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiawei Zhang ◽  
Changzhou Deng ◽  
Weipeng Liu ◽  
Zuoqi Tang ◽  
Yue Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
South China ◽  
Mass Extinction ◽  
Causal Link ◽  
Large Igneous Province ◽  
Late Devonian ◽  
Igneous Province ◽  
Ultimate Cause ◽  
Long Time

The Late Devonian Frasnian–Famennian (F–F) mass extinction has been long-time debated by non-volcanic causes, extra-terrestrial impacts, and large igneous province (LIP) eruptions. To better understand the ultimate cause of the F–F mass extinction, here we investigate the chemostratigraphy of mercury (Hg) and total organic carbon (TOC) on two marine F–F strata in the Dushan area, South China. In both sections, high Hg and Hg/TOC anomalies were observed near the F–F boundary. These anomalies are in line with those recently observed in Morocco, Germany, Poland, and north Russia, suggesting a global Hg flux. The Late Devonian LIP eruptions, which are believed to have emitted massive amounts of Hg, could be responsible for the global Hg and Hg/TOC anomalies around the F–F boundary. The observed Hg and Hg/TOC anomalies coincide with the extinction of Frasnian fauna in the Dushan area, implying a causal link between the Viluy, Kola, and Pripyat-Dnieper-Donets LIP eruptions and the F–F mass extinction.

scholarly journals Mercury anomalies associated with three extinction events (Capitanian Crisis, Latest Permian Extinction and the Smithian/Spathian Extinction) in NW Pangea

2015 ◽  
Vol 153 (2) ◽  
pp. 285-297 ◽  
Author(s):  
STEPHEN E. GRASBY ◽  
BENOIT BEAUCHAMP ◽  
DAVID P.G. BOND ◽  
PAUL B. WIGNALL ◽  
HAMED SANEI
Keyword(s):  
Organic Carbon ◽  
Mass Extinction ◽  
Large Igneous Province ◽  
Early Triassic ◽  
Igneous Province ◽  
Order Of Magnitude ◽  
Permian Extinction ◽  
Extinction Events ◽  
Mass Extinction Events ◽  
Mercury Loading

AbstractStrata of Permian – Early Triassic age that include a record of three major extinction events (Capitanian Crisis, Latest Permian Extinction and the Smithian/Spathian Extinction) were examined at the Festningen section, Spitsbergen. Over thec. 12 Ma record examined, mercury in the sediments shows relatively constant background values of 0.005–0.010 μg g–1. However, there are notable spikes in Hg concentration over an order of magnitude above background associated with the three extinctions. The Hg/total organic carbon (TOC) ratio shows similar large spikes, indicating that they represent a true increase in Hg loading to the environment. We argue that these represent Hg loading events associated with enhanced Hg emissions from large igneous province (LIP) events that are synchronous with the extinctions. The Hg anomalies are consistent across the NW margin of Pangea, indicating that widespread mercury loading occurred. While this provides utility as a chemostratigraphic marker the Hg spikes may also indicate loading of toxic metals to the environment, a contributing cause to the mass extinction events.

Lithostratigraphy of the Palaeoproterozoic Hekpoort Formation (Pretoria Group, Transvaal Supergroup), South Africa

2020 ◽  
Vol 123 (4) ◽  
pp. 655-668
Author(s):  
N. Lenhardt ◽  
W. Altermann ◽  
F. Humbert ◽  
M. de Kock
Keyword(s):  
South Africa ◽  
Bushveld Complex ◽  
Sedimentary Rocks ◽  
Type Locality ◽  
Large Igneous Province ◽  
Braided River ◽  
River Systems ◽  
The West ◽  
Igneous Province ◽  
Transvaal Supergroup

Abstract The Palaeoproterozoic Hekpoort Formation of the Pretoria Group is a lava-dominated unit that has a basin-wide extent throughout the Transvaal sub-basin of South Africa. Additional correlative units may be present in the Kanye sub-basin of Botswana. The key characteristic of the formation is its general geochemical uniformity. Volcaniclastic and other sedimentary rocks are relatively rare throughout the succession but may be dominant in some locations. Hekpoort Formation outcrops are sporadic throughout the basin and mostly occur in the form of gentle hills and valleys, mainly encircling Archaean domes and the Palaeoproterozoic Bushveld Complex (BC). The unit is exposed in the western Pretoria Group basin, sitting unconformably either on the Timeball Hill Formation or Boshoek Formation, which is lenticular there, and on top of the Boshoek Formation in the east of the basin. The unit is unconformably overlain by the Dwaalheuwel Formation. The type-locality for the Hekpoort Formation is the Hekpoort farm (504 IQ Hekpoort), ca. 60 km to the west-southwest of Pretoria. However, no stratotype has ever been proposed. A lectostratotype, i.e., the Mooikloof area in Pretoria East, that can be enhanced by two reference stratotypes are proposed herein. The Hekpoort Formation was deposited in a cratonic subaerial setting, forming a large igneous province (LIP) in which short-termed localised ponds and small braided river systems existed. It therefore forms one of the major Palaeoproterozoic magmatic events on the Kaapvaal Craton.

Ultramafic-alkaline-carbonatite complexes as a result of two-stage melting of mantle plume: evidence from the mid-paleoproterozoic Tiksheozero intrusion, Northern Karelia, Russia

2019 ◽  
Vol 486 (4) ◽  
pp. 460-465
Author(s):  
E. V. Sharkov ◽  
A. V. Chistyakov ◽  
M. M. Bogina ◽  
O. A. Bogatikov ◽  
V. V. Shchiptsov ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Mantle Plume ◽  
Large Igneous Province ◽  
Intrusive Complex ◽  
Incongruent Melting ◽  
Isotopic Data ◽  
Two Stage ◽  
Similar Composition ◽  
Igneous Province ◽  
Alkaline Magmas

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids  that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

The early Statherian (ca. 1800–1750 Ma) Prutivka-Novogol large igneous province of Sarmatia: Geochronology and implication for the Nuna/Columbia supercontinent reconstruction

2021 ◽  
Vol 358 ◽  
pp. 106185
Author(s):  
Leonid Shumlyanskyy ◽  
Richard E. Ernst ◽  
Aleksander Albekov ◽  
Ulf Söderlund ◽  
Simon A. Wilde ◽  
...  
Keyword(s):  
Large Igneous Province ◽  
Columbia Supercontinent ◽  
Igneous Province
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