High-resolution basin-wide sedimentary budget quantification during periods of high-frequency climate change in the active Corinth Rift system, central Greece

The Gulf of Corinth (GoC), central Greece is a relatively young rift (~2 Myr) with high extension rates (10-15 mm/yr) making it an ideal location to study the effects of tectonics and climate on sediment dynamics during early-stage rifting. The GoC’s stratigraphy is divided into two main units separated by a basin-wide unconformity that occurred at ~790 ka. Below the unconformity is a low-amplitude, less-coherent seismic package. Above the unconformity are alternating high-amplitude and low-amplitude seismic packages which correspond respectively to the GoC’s climate-driven connection to and separation from the global ocean.

Using the GoC’s dense network of offshore 2D seismic data tied to IODP Expedition 381 cores, we quantify the sedimentary budget accumulated in the GoC at high resolution (<50 kyr timescale) where seismic resolution allows (present - 330 ka), and lower resolution (<160 kyr) before (330-790 ka). We extract clastic solid volumes from isopachs between 3D seismic surfaces generated from interpretation of multiple 2D surveys. We incorporate uncertainties resulting from the time to depth conversion and the sediment remaining porosity estimated from IODP 381 Site M0079 cores.

Time to depth conversion contributes uncertainty that ranges from 7% at the seafloor to 20% at the basement. Porosity contributes uncertainty that ranges from 8% at the seafloor to 4% at the basement. Estimates of sediment volumes in the high-resolution section range from 4.3 km³ ± 10.3% from 0-15 ka to 7.9 km³ ± 20.1% from 259-294 ka.

We see two stages of increasing sediment accumulation rates over the last 600 ka. Accumulation rates rise from 0.047 ± 20.3% km³/kyr at 592 ka to 0.413 ± 21.0% km³/kyr at 259 ka then from 0.122 ± 15.4% km³/kyr at ~220 ka to 0.302 ± 13.2% km³/kyr at present.

From these preliminary results we will evaluate the relationship between the accumulation volumes and rates in relation to climate, i.e. changes in precipitation due to global glacial-interglacial cycles, and regional tectonics, i.e. the simultaneous uplift of the drainage area and subsidence of the basin.