scholarly journals Mercury deposition in Western Tethys during the Carnian Pluvial Episode (Late Triassic)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mina Mazaheri-Johari ◽  
Piero Gianolla ◽  
Tamsin A. Mather ◽  
Joost Frieling ◽  
Daoliang Chu ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Large Igneous Province ◽  
Late Triassic ◽  
Mercury Deposition ◽  
Western Tethys ◽  
Sedimentary Records ◽  
Environmental Perturbations ◽  
Depositional Settings ◽  
Igneous Province ◽  
Multiple Pulses

AbstractThe Late Triassic Carnian Pluvial Episode (CPE) was a time of biological turnover and environmental perturbations. Within the CPE interval, C-isotope and sedimentary records indicate multiple pulses of depleted carbon into the atmosphere–ocean system linked to discrete enhancements of the hydrological cycle. Data suggest a similar cascade of events to other extinctions, including being potentially driven by emplacement of a large igneous province (LIP). The age of the Wrangellia LIP overlaps that of the CPE, but a direct link between volcanism and the pulsed CPE remains elusive. We present sedimentary Hg concentrations from Western Tethys successions to investigate volcanic activity through the previously established CPE global negative C-isotope excursions (NCIEs). Higher Hg concentrations and Hg/TOC are recorded just before and during NCIEs and siliciclastic inputs. The depositional settings suggest volcanic Hg inputs into the basins over the NCIEs rather than increases of Hg drawdown or riverine transport. Differences in Hg and Hg/TOC signals between the basins might be linked to coeval LIP style or the temporal resolution of the sedimentary successions. Overall, our new data provide support for a link between pulses of Wrangellia LIP volcanism, NCIEs, and humid phases that mark the CPE in the Western Tethys.

scholarly journals Volcanically driven lacustrine ecosystem changes during the Carnian Pluvial Episode (Late Triassic)

2021 ◽  
Vol 118 (40) ◽  
pp. e2109895118 ◽  
Author(s):  
Jing Lu ◽  
Peixin Zhang ◽  
Jacopo Dal Corso ◽  
Minfang Yang ◽  
Paul B. Wignall ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
North China ◽  
Climatic Changes ◽  
Large Igneous Province ◽  
Late Triassic ◽  
C Cycle ◽  
Igneous Province ◽  
Ecosystem Changes ◽  
Lacustrine Ecosystem

The Late Triassic Carnian Pluvial Episode (CPE) saw a dramatic increase in global humidity and temperature that has been linked to the large-scale volcanism of the Wrangellia large igneous province. The climatic changes coincide with a major biological turnover on land that included the ascent of the dinosaurs and the origin of modern conifers. However, linking the disparate cause and effects of the CPE has yet to be achieved because of the lack of a detailed terrestrial record of these events. Here, we present a multidisciplinary record of volcanism and environmental change from an expanded Carnian lake succession of the Jiyuan Basin, North China. New U–Pb zircon dating, high-resolution chemostratigraphy, and palynological and sedimentological data reveal that terrestrial conditions in the region were in remarkable lockstep with the large-scale volcanism. Using the sedimentary mercury record as a proxy for eruptions reveals four discrete episodes during the CPE interval (ca. 234.0 to 232.4 Ma). Each eruptive phase correlated with large, negative C isotope excursions and major climatic changes to more humid conditions (marked by increased importance of hygrophytic plants), lake expansion, and eutrophication. Our results show that large igneous province eruptions can occur in multiple, discrete pulses, rather than showing a simple acme-and-decline history, and demonstrate their powerful ability to alter the global C cycle, cause climate change, and drive macroevolution, at least in the Triassic.

Latitudinal selectivity of foraminifer extinctions during the late Guadalupian crisis

Paleobiology ◽  
2009 ◽  
Vol 35 (4) ◽  
pp. 465-483 ◽  
Author(s):  
David P. G. Bond ◽  
Paul B. Wignall
Keyword(s):  
Large Igneous Province ◽  
Upper Permian ◽  
Marine Habitat ◽  
Shallow Marine ◽  
Western Tethys ◽  
Global Database ◽  
Igneous Province ◽  
Global Extinction ◽  
Radiation Regime ◽  
Regional Selectivity

A global database of middle–upper Permian foraminiferal genera has been compiled from the literature for 75 Guadalupian and 62 Lopingian localities, grouped into 32 and 19 operational geographical units respectively. Cluster analysis reveals that five distinct Guadalupian provinces were reduced to four in the Lopingian, following the disappearance of the Eastern Panthalassa Province. Extinction magnitudes across the Guadalupian/Lopingian (G/L) boundary reveal that, in the remaining provinces, there is a strong regional variation to the losses at low paleolatitudes. The Central and Western Tethys Province experienced a markedly lower extinction magnitude, at both provincial and global levels, than the Eastern and Northern Tethys Province. Panthalassa experienced a high extinction magnitude of endemics, but a global extinction magnitude similar to that recorded in Central and Western Tethys. This regional bias is seen in both the fusulinacean and non-fusulinacean foraminifera, although fusulinaceans suffered much higher magnitudes of extinction. The regional selectivity also persisted during the subsequent Lopingian radiations, with the Central and Western Tethys Province recording the greatest magnitudes. Thus, of 35 new genera recorded globally from the Lopingian, 27 of these are recorded in Central and Western Tethys, compared to five and 12 genera respectively in Panthalassa and in Eastern and Northern Tethys. The Emeishan large igneous province erupted within the Eastern and Northern Tethys Province and may have been a factor in the high extinction–low radiation regime of this region. Regression (and consequent shallow-marine habitat loss) also appears to have been a significant factor. A major, but brief, late Guadalupian regression is best seen in those areas that suffered the greatest extinction losses.

scholarly journals Globally enhanced mercury deposition during the end-Pliensbachian extinction and Toarcian OAE: A link to the Karoo–Ferrar Large Igneous Province

2015 ◽  
Vol 428 ◽  
pp. 267-280 ◽  
Author(s):  
L.M.E. Percival ◽  
M.L.I. Witt ◽  
T.A. Mather ◽  
M. Hermoso ◽  
H.C. Jenkyns ◽  
...  
Keyword(s):  
Large Igneous Province ◽  
Mercury Deposition ◽  
Igneous Province

scholarly journals The Carnian Humid Episode of the late Triassic: a review

2015 ◽  
Vol 153 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. RUFFELL ◽  
M. J. SIMMS ◽  
P. B. WIGNALL
Keyword(s):  
Climate Change ◽  
Middle Eastern ◽  
Large Igneous Province ◽  
Late Triassic ◽  
Exact Nature ◽  
Carbon Isotope Excursion ◽  
Igneous Province ◽  
Ultimate Cause ◽  
New Evidence ◽  
Carnian Stage

AbstractFrom 1989 to 1994 a series of papers outlined evidence for a brief episode of climate change from arid to humid, and then back to arid, during the Carnian Stage of the late Triassic Epoch. This time of climate change was compared to marine and terrestrial biotic changes, mainly extinction and then radiation of flora and fauna. Subsequently termed, albeit incorrectly, the Carnian Pluvial Event (CPE) by successive authors, interest in this episode of climatic change has increased steadily, with new evidence being published as well as several challenges to the theory. The exact nature of this humid episode, whether reflecting widespread precipitation or more local effects, as well as its ultimate cause, remains equivocal. Bed-by-bed sampling of the Carnian in the Southern Alps (Dolomites) shows the episode began with a negative carbon isotope excursion that lasted for only part of one ammonoid zone (A. austriacum). However, that the Carnian Humid Episode represents a significantly longer period, both environmentally and biotically, is irrefutable. The evidence is strongest in the European, Middle Eastern, Himalayan, North American and Japanese successions, but not always so clear in South America, Antarctica and Australia. The eruption of the Wrangellia Large Igneous Province and global warming (causing increased evaporation in the Tethyan and Panthalassic oceans) are suggested as causes for the humid episode.

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.

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