High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift

Area of Science:

• Geosciences
• Paleoclimatology
• Tectonics

Background:

• Young rift basins evolve through complex interactions between tectonic forces, surface processes, and climate.
• Understanding these interactions over extended periods, especially during early development, is crucial but limited by available geological records.

Purpose of the Study:

• To reconstruct the longest and highest-resolution record of sediment flux and paleoenvironmental change in a young rift basin connected to the global ocean.
• To investigate the interplay between eustatic sea level fluctuations and sediment delivery into the Corinth Rift.

Main Methods:

• Analysis of sediment cores from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift.
• Reconstruction of paleoenvironmental conditions, including sedimentation rates, bioturbation, and organic carbon concentration.
• Correlation of sedimentary changes with orbital-scale climate cycles and sea-level fluctuations.

Main Results:

• Identified 10s-100s of thousands of years (kyr) cyclic variations in the Corinth Rift's paleoenvironment.
• Observed significant changes in sediment volume and character corresponding to sea-level fluctuations and basin isolation/connection.
• Documented higher sedimentation rates (~2-7 times) during glacial periods (isolated basin) compared to interglacials (marine basin), linked to reduced vegetation cover and increased flank erosion.

Conclusions:

• Orbital-scale sea-level changes significantly influence sediment flux and paleoenvironmental conditions in young rift basins.
• These infill dynamics can impact early rift sedimentary and faulting processes, affecting syn-rift stratigraphy and sediment burial.
• Findings have implications for understanding organic carbon flux and preservation on continental margins globally.