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TitleMercury evidence of Deccan volcanism driving the Latest Maastrichtian warming event
AuthorLi, S; Grasby, S EORCID logo; Zhao, X; Chen, J; Zheng, D; Wang, H; Fang, Y; Zhang, Q; Yu, T; Tian, J; Du, S; Jarzembowski, E A; Wang, Q; Zhang, H; Wan, X; Wang, B
SourceGeology vol. 50, no. 10, 2022 p. 1140-1144, Open Access logo Open Access
Alt SeriesNatural Resources Canada, Contribution Series 20220394
PublisherGeological Society of America
Mediapaper; digital; on-line
File formatpdf
AreaPingyi Basin; Jiaolai Basin; China
Lat/Long WENS-180.0000 180.0000 90.0000 -90.0000
Subjectsigneous and metamorphic petrology; Science and Technology; igneous petrology; volcanism; mercury; mercury geochemistry
Illustrationslocation maps; plots
ProgramGEM2: Geo-mapping for Energy and Minerals Western Arctic, Pearya Terrane, North Ellesmere
Released2022 07 18
AbstractThe timing and ecological impacts of the Deccan Traps large igneous province eruption are vigorously debated. Pre-Cretaceous-Paleogene (KPg) boundary impacts of Deccan volcanism have been widely identified in marine sediments, but direct evidence of terrestrial impacts remains rare. We used mercury concentrations and isotopic compositions, a proxy for volcanic activity, to assess impacts on terrestrial environments. We studied two drill cores across the KPg boundary in eastern China that represent two different depositional environments: clastic deposits in the Jiaolai Basin and carbonate deposits in the Pingyi Basin. Both drill cores exhibit strong Hg enrichment prior to the KPg boundary. Near consistent mass-independent fractionation (MIF) of odd-Hg isotopes (odd-MIF) in the Jiaolai Basin likely indicates a volcanogenic source of Hg spikes below the KPg boundary. Odd-MIF isotopes in the Pingyi Basin likewise suggest a volcanogenic Hg source but with a terrestrial Hg signature of lower D199Hg values before and after the Hg spike interval. The Hg enrichment level can be stratigraphically correlated to the beginning of the Latest Maastrichtian warming event (LMWE) and is consistent with a strong, negative carbon-isotope excursion (CIE) in both d13Corg (organic matter) and d13Ccarb (carbonate), suggesting a disturbance of the global carbon cycle induced by a major pulse of Deccan Traps volcanism. Our discovery of a ter-restrial record of pre-KPg boundary Deccan volcanism provides robust evidence of global influence of the Deccan Traps large igneous province during the LMWE.
Summary(Plain Language Summary, not published)
The Late Cretaceous experienced significant climate change, including greenhouse warming, ocean anoxia, and mass extinction. Understanding the drivers of these changes can provide critical insight into modern climate risk. This study used novel tools of mercury chemostratigraphy developed by GSC scientists under GEM to examine the role of volcanic released CO2 on climate. Results show significant warming related to massive volcanism CO2 release in the Late Cretaceous leading to the extinction of the dinosaurs. This implies that the earth was under significant climate stress when hit by a large asteroid, This greenhouse event may have created already weakened environmental conditions making the earth more vulnerable to an impact.

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