Grain-size analysis of the Late Pleistocene sediments in the Corinth Rift: insights into strait-influenced hydrodynamics and provenance of an active rift basin

Abstract

Grain-size analysis of the sediments in borehole M0079A, which is located in the Corinth Rift, was used to explore hydrodynamic conditions and provenance in the Late Pleistcene Corinth Rift. Grain-size populations that were sensitive to the sedimentary environments were characterized by frequency distribution, particle size-standard deviation, and probability cumulative curves. Our results indicate the grain-size population component in the range 0.15-0.25 μm may be used as a sensitive proxy for hyperpycnal flows, which have commonly been triggered by river floods from the southern margin of the rift since ca. 0.593–0.613 Ma. The high-density plumes derived from the longer rivers of the southern rift that were prevalent before ca. 0.593–0.613 Ma. When sediment is supplied as hemipelagic deposition, the proportion of the total grain-size population that is in the 0.3–0.5 μm range becomes an index for suspension fall-out deposits. The core shows coarser sediments during the marine periods and this may be linked to the current circulation related to the Ishtmia Strait opening. The study thus illustrates how the establishment of interbasinal straits can influence the details of sedimentary hydrodynamics in the deep-water axis of an adjacent depocenter.

Straits and seaways: controls, processes and implications in modern and ancient systems

“…An interesting feature in the sill is the presence of elongate morphological features, interpreted in the past as erosional scours and here suggested to possibly represent fossil sand waves formed at low sea-level and then stabilized by encrusting biota. Kang et al (2022) and Caterina et al (2022) present palaeoenvironmental reconstructions from the Gulf of Corinth area. Kang et al (2022) describe the detailed sedimentology of the fine-grained silty and sandy gravity flow deposits filling the Gulf of Corinth.…”

“…Kang et al (2022) and Caterina et al (2022) present palaeoenvironmental reconstructions from the Gulf of Corinth area. Kang et al (2022) describe the detailed sedimentology of the fine-grained silty and sandy gravity flow deposits filling the Gulf of Corinth. Using grain-size and geochemistry analyses on long well cores, centimetre-to decimetre-thick beds are interpreted to be deposited under distinct hydrodynamic conditions.…”