Mass Extinctions, Volcanism, and Impacts: New Developments
This volume covers new developments and research on mass extinctions, volcanism, and impacts, ranging from the ancient Central Iapetus magmatic province linked with the Gaskiers glaciation to thermogenic degassing in large igneous provinces, the global mercury enrichment in Valanginian sediments, and the Guerrero-Morelos carbonate platform response to the Caribbean-Colombian Cretaceous large igneous province. This section is followed by a series of end-Cretaceous studies, including the implications for the Cretaceous-Paleogene boundary event in shallow platform environments and correlation to the deep sea; the role of wildfires linked to Deccan volcanism on ecosystems from the Indian subcontinent; rock magnetic and mineralogical study of Deccan red boles; and factors leading to the collapse of producers during Deccan Traps eruptions and the Chicxulub impact.
Global mercury enrichment in Valanginian sediments supports a volcanic trigger for the Weissert episode
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Published:March 06, 2020
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CiteCitation
Guillaume Charbonnier*, Thierry Adatte, Stéphanie Duchamp-Alphonse, Jorge E. Spangenberg, Karl B. Föllmi, 2020. "Global mercury enrichment in Valanginian sediments supports a volcanic trigger for the Weissert episode", Mass Extinctions, Volcanism, and Impacts: New Developments, Thierry Adatte, David P.G. Bond, Gerta Keller
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ABSTRACT
Recently, a set of mercury (Hg) anomalies in Valanginian sediments recovered from European sections demonstrated that an important magmatic pulse occurred at the onset of the Weissert episode. In this study, we report the distribution of Hg contents near the onset of the Weissert episode from localities outside of Europe, in the proto–Atlantic Ocean (Blake Bahama and Cap Hatteras Basins, Deep Sea Drilling Project [DSDP] Holes 534A and 603B) and southern Tethys Ocean (Argo Abyssal Plain, Ocean Drilling Program [ODP] Hole 765C), in order to evaluate the global impact of volcanism during the Valanginian. In addition, we also reinvestigated the Orpierre and Angles sections of the Vocontian Basin at a very high time resolution, to examine the potential impact of regional volcanic activity during that time interval. The onset of the Weissert episode in the proto-Atlantic and in the southern Tethyan cores is marked by significant increases in Hg contents. The persistence of the Hg anomaly in Hg/total organic carbon and Hg/Al ratios suggests that Hg enrichments were not primarily controlled by runoff processes and/or redox conditions, but instead indicate an increase in volcanic activity. The Hg enrichments recorded from localities outside of Europe at different latitudes were correlated to those previously observed in European sections, thereby confirming the presence of a global Hg peak at the onset of the Weissert episode. This peak was probably related to the emplacement of the Paraná-Etendeka large igneous province, suggesting a key role for volcanic activity during the Valanginian global environmental perturbations. In coeval intervals in the Vocontian Basin, Hg records show abrupt and short-lived enrichments, which correspond in the sedimentary successions to a goethite-rich ocher-colored layer. Two regional processes could explain Hg deposition and sequestration in this region: increased Hg sequestration by organic matter production in an oxygen-depleted environment, and/or the presence of regional volcanic activity, which is also indicated by the occurrence of a distal volcanic ash layer.
- aluminum
- Ammonites
- Ammonoidea
- Argo abyssal plain
- Atlantic Ocean
- Berriasian
- biostratigraphy
- Blake-Bahama Basin
- C-13/C-12
- carbon
- Cephalopoda
- continental rise
- Cretaceous
- Deep Sea Drilling Project
- deposition
- DSDP Site 534
- DSDP Site 603
- Eh
- emplacement
- Europe
- Foraminifera
- France
- geochemical anomalies
- Hatteras abyssal plain
- high-resolution methods
- igneous rocks
- Indian Ocean
- IPOD
- isotope ratios
- isotopes
- large igneous provinces
- Leg 76
- Leg 123
- Lower Cretaceous
- magmatism
- magnetostratigraphy
- major elements
- mercury
- Mesozoic
- metals
- microfossils
- Mollusca
- nannofossils
- nannoplankton
- North Atlantic
- Ocean Drilling Program
- ocean floors
- ODP Site 765
- organic compounds
- paleolatitude
- paleomagnetism
- plankton
- processes
- pyroclastics
- Radiolaria
- sediments
- stable isotopes
- Tethys
- total organic carbon
- Valanginian
- Vocontian Trough
- volcanic ash
- volcanic rocks
- volcanism
- Western Europe
- southeastern France
- Vocontian Basin
- upper Berriasian
- Angles France
- Parana-Etendeka large igneous province
- Weissert episode