Late Quaternary mud‐dominated, basin‐floor sedimentation of the Gulf of Corinth, Greece: Implications for deep‐water depositional processes and controls on syn‐rift sedimentation

Abstract

Syn-rift deep-water muds and mudstones preserve a relatively complete stratigraphic record of tectonic and climatic events. This paper investigates muddominated deposits and stratigraphy using core from International Ocean Discovery Program (IODP) Expedition 381 sites M0078 and M0079 in the Gulf of Corinth, Greece. Millimetre-scale logging defined several bed types: homogeneous and laminated mud beds, bioturbated beds, a variety of graded beds, and rare matrix-supported conglomerates and slumps. Homogeneous muds and light grey to black laminated muds record deposition from distal, waning low density turbidity currents and terminal mud-rich quasi-laminar or laminar plug flows. Graded beds, interpreted as turbidites, range from beds several millimetre to a few centimetres of mud with silt to fine sand bases, to metre-scale mud beds with coarser sand and pebble bases. Conglomerate and slumped beds record cohesive debris flows, transitional flows and slope failure. Three stratal package types are distinguished: bioturbated, bedded and laminated, recording distinct hydrological conditions. Bioturbated packages record interglacial marine conditions with well oxygenated waters. Bedded packages record hemipelagic processes and low energy density underflows in a mainly dysoxic, stratified, lacustrine setting (glacial phases). In laminated packages, white mm-scale laminae of calcite or aragonite from varved, hemipelagic sediments demonstrating seasonal variability in a dysoxic non-marine or transitional setting. Rift stratigraphy is linked to eustatically controlled connections to the global ocean across rift segment boundaries. The ca. 780 to 330 ka succession is dominated by laminated packages with thin bioturbated packages and distinct conglomerates and slumps, suggesting high sills, making ocean connections brief and transitional to lacustrine conditions prolonged. The ca. 330 ka to present succession shows well developed bioturbated and bedded packages, separated by thin laminated packages, suggesting 2 | EAGE GAWTHORPE et al.

Vegetation Composition in a Typical Mediterranean Setting (Gulf of Corinth, Greece) during Successive Quaternary Climatic Cycles

“…The boundary between LU1 and LU2, at 385.14 mbsf, is evidenced by an abrupt shift from laminated greenish gray muds to homogeneous light gray muds [23]. [25,26]). In the inset map, the location of regional pollen records is also represented wit Ioannina (I), Lake Ohrid (LO), Lake Prespa (LP), Tenaghi Philippon (TP) and Kopais (K…”

“…The Brunhes/Matuyama boundary (MBB, 773 ka [27]) of M0078 ha orded at the depth of 386 mbsf, close to the boundary between LU1 and LU addition, the proposed occurrence of the Jaramillo Subchron (1000-1080 k 519.32 and 574.72 mbsf provides further independent chronostratigraphic poin ther age control points using coccolithophore assemblages are limited only to (interglacial) intervals when the basin was connected to the Mediterranean Sea fore, the last occurrence of Pseudoemiliania lacunosa recorded at 298.6 mbsf is not the true last appearance (LAD) at 430 ka [28] as it is recorded during the low 12, when the Gulf of Corinth was isolated from the Mediterranean Sea [23]. age constraints are obtained through stratigraphic correlation with the neigh M0079, while the age-depth model is based on magnetostratigraphy and pala data [29], as well as several Th/U absolute datings [26]. Gawthorpe et al [26] three types of stratal packages (bioturbated, laminated and bedded), which allo detailed stratigraphic subdivision of lithostratigraphic unit 1, leading to a new lution correlation of stratal packages between sites M0078 and M0079, both from the central of the Gulf of Corinth, from MIS 1-13 (Figure 2).…”

“…Gawthorpe et al [26] three types of stratal packages (bioturbated, laminated and bedded), which allo detailed stratigraphic subdivision of lithostratigraphic unit 1, leading to a new lution correlation of stratal packages between sites M0078 and M0079, both from the central of the Gulf of Corinth, from MIS 1-13 (Figure 2). [25,26]). In the inset map, the location of regional pollen records is also represented with black dots: Ioannina (I), Lake Ohrid (LO), Lake Prespa (LP), Tenaghi Philippon (TP) and Kopais (K).…”

“…Therefore, the last occurrence of Pseudoemiliania lacunosa recorded at 298.6 mbsf is most likely not the true last appearance (LAD) at 430 ka [28] as it is recorded during the lowstand MIS 12, when the Gulf of Corinth was isolated from the Mediterranean Sea [23]. Additional age constraints are obtained through stratigraphic correlation with the neighboring site M0079, while the age-depth model is based on magnetostratigraphy and palaeointensity data [29], as well as several Th/U absolute datings [26]. Gawthorpe et al [26] recognized three types of stratal packages (bioturbated, laminated and bedded), which allowed a new detailed stratigraphic subdivision of lithostratigraphic unit 1, leading to a new high-resolution correlation of stratal packages between sites M0078 and M0079, both originating from the central of the Gulf of Corinth, from MIS 1-13 (Figure 2).…”

Transition From Late‐Miocene Syn‐Orogenic Extension to Plio‐Pleistocene Corinth Rifting in the Southern Hellenides, Northern Peloponnese, Greece

“…The late Rift 2 is characterized from ca. 0.8 Ma by a second northward migration of fault activity and by the alternation of lacustrine and marine Tectonics 10.1029/2023TC007964 conditions (Fernández-Blanco et al, 2019;Ford et al, 2016;Gawthorpe et al, 2018Gawthorpe et al, , 2022McNeill et al, 2019;Rohais & Moretti, 2017).…”