Fullerenes and interplanetary dust at the Permian-Triassic boundary.

Area of Science:

• Geochemistry
• Paleontology
• Planetary Science

Background:

• The Permian-Triassic boundary (PTB) marks the most severe mass extinction event in Earth's history.
• Previous research suggested an impact event at the PTB.
• Fullerenes are novel extraterrestrial tracers capable of trapping noble gases.

Purpose of the Study:

• To present new evidence for extraterrestrial fullerenes at the PTB in Antarctica.
• To identify the source of noble gases in PTB sediments.
• To differentiate between impact-related and interplanetary dust particle (IDP) contributions.

Main Methods:

• Analysis of fullerene-containing sediments from Graphite Peak, Antarctica.
• Noble gas isotopic analysis of bulk sediments and isolated magnetic fractions.
• Comparison of isotopic signatures with known extraterrestrial and terrestrial sources.

Main Results:

• Extraterrestrial fullerenes with trapped noble gases were identified at the PTB in Antarctica.
• A (3)He-rich magnetic fraction was isolated, showing isotopic compositions similar to interplanetary dust particles (IDPs).
• Helium and neon isotopic compositions in bulk sediments and magnetic fractions are consistent with solar-type gases from IDP flux.

Conclusions:

• The study confirms the presence of extraterrestrial fullerenes at the PTB, supporting a giant impact hypothesis for the mass extinction.
• Distinct noble gas signatures indicate a dual extraterrestrial source: giant impacts (fullerenes) and IDP flux (solar-type gases).
• This research successfully decouples the fullerene tracer from the IDP tracer, providing clearer insights into PTB events.