Draft:Mercury Anomaly

• Comment: The Broader Applications section needs a reference at least, and at least 3 refs would be good. Graeme Bartlett (talk) 08:18, 12 May 2025 (UTC)

• Comment: In accordance with Wikipedia's Conflict of interest policy, I disclose that I have a conflict of interest regarding the subject of this article. Rugmaster (talk) 18:51, 9 May 2025 (UTC)

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Mercury Anomalies (Geology) Mercury anomalies in geology refer to unusual increases in mercury (Hg) concentrations within sedimentary layers. These anomalies are interpreted as geochemical indicators of significant volcanic activity, particularly associated with Large Igneous Provinces (LIPs), which release substantial quantities of mercury into the atmosphere. Once released, mercury is deposited globally through atmospheric transport and settles into marine and terrestrial sediments, leaving a traceable geochemical signal of these events.

Scientific Background Mercury is a volatile element that can be emitted in large amounts during volcanic eruptions, especially during extensive LIP events. In normal sedimentary settings, mercury concentrations remain low and are primarily controlled by background volcanic input and organic matter sequestration. However, during episodes of massive volcanism, mercury emissions can overwhelm natural sequestration processes, resulting in anomalously high concentrations in sedimentary records. These anomalies can thus serve as a global stratigraphic marker for volcanic episodes and are increasingly used in paleoclimatology and extinction research.

Latest Permian Extinction and the 2012 Breakthrough The idea of using mercury anomalies as a proxy for LIP volcanism and associated mass extinction events was first formally proposed by Hamed Sanei, Stephen Grasby, and Benoit Beauchamp in a landmark 2012 paper titled Latest Permian Mercury Anomalies, published in the journal Geology. The study analyzed sedimentary sections from Buchanan Lake in the Canadian High Arctic and found elevated mercury concentrations coinciding with the Latest Permian Extinction (LPE)—the most severe mass extinction in Earth's history, occurring approximately 252 million years ago.

The authors proposed that these mercury anomalies were caused by intense volcanic activity from the Siberian Traps, one of the largest known LIPs. The associated volcanic outgassing released vast amounts of mercury and other volatiles into the atmosphere, disrupting oceanic mercury cycles and causing environmental stress such as ocean acidification and climate change.

Key Findings: Elevated Mercury Levels: A pronounced increase in sedimentary mercury concentrations is observed in strata corresponding to the LPE interval.

Disruption of Sequestration: Normal organic binding processes for mercury were likely overwhelmed, resulting in higher levels of dissolved mercury in marine systems.

Volcanic Linkage: The timing and intensity of mercury spikes strongly correlate with the onset of Siberian Traps volcanism.

Broader Applications Following the 2012 study, mercury anomalies have been used to investigate other extinction intervals, including the Capitanian crisis, the end-Triassic extinction, and the Early Toarcian Oceanic Anoxic Event. In each case, elevated mercury levels are linked to known or suspected episodes of LIP volcanism, supporting the role of large-scale volcanic events in global environmental disruption.

Mercury anomalies are now considered a valuable tool in stratigraphy and extinction studies, often used alongside carbon isotopes, trace metal geochemistry, and paleontological evidence to reconstruct past environmental conditions.

References Sanei, H., Grasby, S. E., & Beauchamp, B. (2012). Latest Permian mercury anomalies. Geology, 40(1), 63–66. https://doi.org/10.1130/G32596.1

See Also Large Igneous Province

Siberian Traps

Permian–Triassic extinction event

Geochemical proxies

Paleoclimatology