scholarly journals Toxic mercury pulses into late Permian terrestrial and marine environments

Geology ◽  
2020 ◽  
Vol 48 (8) ◽  
pp. 830-833 ◽  
Author(s):  
Stephen E. Grasby ◽  
Xiaojun Liu ◽  
Runsheng Yin ◽  
Richard E. Ernst ◽  
Zhuoheng Chen
Keyword(s):  
Trophic Levels ◽  
Large Igneous Province ◽  
Late Permian ◽  
Volcanic Emissions ◽  
Loading Rates ◽  
Siberian Traps ◽  
Igneous Province ◽  
Permian Extinction ◽  
Potential Impact ◽  
Normal Background

Abstract Large spikes in mercury (Hg) concentration are observed globally at the latest Permian extinction (LPE) horizon that are thought to be related to enhanced volcanic emissions of the Siberian Traps large igneous province (LIP). While forming an effective chemostratigraphic marker, it remains unclear whether such enhanced volcanic Hg emissions could have generated toxic conditions that contributed to extinction processes. To address this, we examined the nature of enhanced Hg emissions from the Siberian Traps LIP and the potential impact it may have had on global ecosystems during the LPE. Model results for a LIP eruption predict that pulses of Hg emissions to the atmosphere would have been orders of magnitude greater than normal background conditions. When deposited into world environments, this would have generated a series of toxic shocks, each lasting >1000 yr. Such repeated Hg loading events would have had severe impact across marine trophic levels, as well as been toxic to terrestrial plant and animal life. Such high Hg loading rates may help explain the co-occurrence of marine and terrestrial extinctions.

Volatile concentrations in olivine-hosted melt inclusions from meimechite and melanephelinite lavas of the Siberian Traps Large Igneous Province: Evidence for flux-related high-Ti, high-Mg magmatism

2018 ◽  
Vol 483 ◽  
pp. 442-462 ◽  
Author(s):  
Alexei V. Ivanov ◽  
Samuel B. Mukasa ◽  
Vadim S. Kamenetsky ◽  
Michael Ackerson ◽  
Elena I. Demonterova ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Large Igneous Province ◽  
Siberian Traps ◽  
Igneous Province

scholarly journals Geochemical characteristics of the Muong Hum alkaline granite in the Phan Si Pan zone, Northwestern Vietnam

2017 ◽  
Vol 1 (T2) ◽  
pp. 114-123
Author(s):  
Minh Pham ◽  
Hieu Trung Pham ◽  
Hoang Kim Nguyen
Keyword(s):  
Geochemical Characteristics ◽  
Red River ◽  
Large Igneous Province ◽  
Direct Result ◽  
Chemical Characteristics ◽  
Late Permian ◽  
Alkaline Granite ◽  
Igneous Province ◽  
Mineral Assemblages ◽  
Alkaline Feldspar

Alkaline granites of the Muong Hum are distributed mainly in the NW Phan Si Pan zone. The granite closely has striped or clear gneissoid structures, coinciding with general NW-SE trends. It consists mainly of plagioclase (~20–30 %), alkaline feldspar (~30–50 %), quartz (~20–25 %), biotite (~1–5 %), aegirine (~1–3 %), and riebeckite (~1–2 %). It has 10,000×Ga/Al ratios of 4.70–4.93, A/CNK values of 0.87–0.90, and negative Eu-anomalies as well as apparent depletion of Ba, Sr, Ti, and P. The mineral assemblages and chemical characteristics show that it is typical of A-type granites. Compared with other adjacent Late Permian to Early Triassic A-type granitic plutons, geochemical characteristics of the Muong Hum granite are similar to the Phu Sa Phìn, Phan Si Pan, Ye Yen Sun, and Nam Xe-Tam Duong granites in NW Vietnam as well as the Taihe, and Panzhihua granites in SW China. Thus, the Phan Si Pan zone must have been a displaced portion of the Emeishan large igneous province. This might be a direct result of the left-lateral Cenozoic Red River shear zone.

scholarly journals Late Permian High-Ti Basalt in Western Guangxi, SW China and Its Link With the Emeishan Large Igneous Province: Geochronological and Geochemical Perspectives

2021 ◽  
Vol 9 ◽  
Author(s):  
Chenguang Zhang ◽  
Renyu Zeng ◽  
Changming Li ◽  
Jian Jiang ◽  
Tianguo Wang ◽  
...  
Keyword(s):  
Weighted Average ◽  
Large Igneous Province ◽  
Late Permian ◽  
Flood Basalts ◽  
Sw China ◽  
Continental Flood Basalts ◽  
Emeishan Large Igneous Province ◽  
Igneous Province ◽  
The Difference ◽  
Emeishan Lip

High-Ti (Ti/Y) flood basalts are widely distributed in the Late Permian Emeishan large igneous province (LIP), SW China, and their spatial distribution and genetic mechanism are important to reveal the role of plume-lithosphere interactions in the LIP origin. Western Guangxi is located on the eastern edge of Emeishan LIP. To explore the genesis of the high-Ti basalt in western Guangxi and any genetic link with the Emeishan LIP, we performed whole-rock geochemical and Sr-Nd isotope and zircon U-Pb-Hf isotope analyses on the Longlin basalts from western Guangxi. The results indicate that the Longlin basalt from Tongdeng area has relatively high SiO2 but low MgO and TFe2O3 contents. The rocks have zircon εHf(t) = −0.42 to 6.41, whole-rock (87Sr/86Sr)i = 0.707167–0.707345, and εNd(t) = −2.5 to −2.14. In contrast, the Longlin basalt from Zhoudong area has relatively low SiO2 but high MgO and TFe2O3 contents. The rocks have whole-rock (87Sr/86Sr)i = 0.706181–0.706191 and εNd(t) = −0.57 to 0.69. Four Longlin basalt samples display LREE enrichments and HREE depletions, and with indistinct δEu and δCe anomalies. LA-ICP-MS zircon U-Pb dating on three Longlin basalt samples (from different localities) yielded consistent weighted average age of 257.9 ± 2.6 Ma (MSWD = 0.55), 259.5 ± 0.75 Ma (MSWD = 3.0), and 256.7 ± 2.0 Ma (MSWD = 0.68), indicating a Late Permian emplacement. Considering the similar age and geochemical features between the Longlin basalt and Emeishan flood basalts, we interpret that the former is spatially, and temporally associated with the Emeishan LIP. Geochemical features show that the high-Ti basalts in western Guangxi resemble Deccan-type continental flood basalts (CFBs), which were derived by decompression melting of the mantle plume. Combined with previous geochemical studies, we suggest that the difference in Ti content and Ti/Y ratio in CFBs are related to the depth and melting degree of mantle source, in which high-Ti features may have been linked to low degree of partial melting in the deep mantle.

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