A TEX₈₆ surface sediment database and extended Bayesian calibration

Area of Science:

• Paleoclimatology
• Marine Geochemistry
• Organic Geochemistry

Background:

• Quantitative paleotemperature estimates are crucial for understanding past climate dynamics.
• Marine sediment proxies require accurate calibration with modern environmental conditions for reliable reconstructions.
• The TEX86 proxy, derived from marine archaeal glycerol dialkyl glycerol tetraether (GDGT) lipids, is a key tool for paleotemperature reconstruction.

Purpose of the Study:

• To present a comprehensive, machine-readable database of 1095 TEX86 surface sediment measurements.
• To update and improve surface and subsurface temperature calibration models for the TEX86 proxy.
• To demonstrate the enhanced applicability of the TEX86 proxy for predicting past ocean temperatures.

Main Methods:

• Compilation of a large dataset of TEX86 measurements from marine surface sediments.
• Inclusion of geospatial information, lipid fractional abundances, and metadata for each sample.
• Development and refinement of TEX86 temperature calibration models using the new database.

Main Results:

• The TEX86 database confirms a robust relationship between surface sediment GDGT distribution and temperature.
• Temperature variations account for over 70% of the variance observed in the TEX86 data.
• The updated calibration models enhance the accuracy of TEX86-based paleotemperature reconstructions.

Conclusions:

• The presented TEX86 database is a valuable resource for paleoclimate research.
• The updated calibration models improve the reliability of past temperature predictions using the TEX86 proxy.
• Future research can leverage this dataset to explore secondary factors influencing GDGT distributions, such as archaeal community composition.