Seep-carbonate lamination controlled by cyclic particle flux

Area of Science:

• Geochemistry
• Paleoclimatology
• Marine Geology

Background:

• Authigenic carbonate build-ups form at seafloor methane seeps.
• Microbial processes drive methane oxidation and carbonate precipitation.
• These build-ups are known archives of methane seepage but not atmospheric processes.

Purpose of the Study:

• To investigate the role of authigenic carbonate build-ups as archives of atmospheric processes.
• To explore the relationship between Indian monsoon cycles and carbonate formation.
• To establish a high-resolution record of past monsoon activity.

Main Methods:

• Analysis of a laminated carbonate build-up from the Arabian Sea.
• Uranium-Thorium (U-Th) dating of the carbonate.
• Correlation of sedimentation pulses with Indian monsoon activity.

Main Results:

• A well-laminated carbonate build-up was identified off Pakistan.
• The build-up formed due to methane-derived aragonite precipitation.
• U-Th dating revealed continuous growth over the past ~1,130 years.
• Sedimentation pulses linked to the Indian monsoon controlled build-up formation.

Conclusions:

• Authigenic carbonate build-ups can serve as high-resolution archives of the Indian monsoon system.
• Monsoon-controlled seep-carbonate formation reveals a novel connection between atmospheric and seafloor processes.
• This extends the known environmental records preserved in methane-derived carbonates.