Sedimentary response to Milankovitch-type climatic oscillations and formation of sediment undulations: evidence from a shallow-shelf setting at Gela Basin on the Sicilian continental margin

摘要: Abstract A multi-proxy chronological framework along with sequence-stratigraphic interpretations unveils composite Milankovitch cyclicity in the sedimentary records of Last Glacial–Interglacial cycle at NE Gela Basin on Sicilian continental margin. Chronostratigraphic data (including foraminifera-based eco-biostratigraphy and δ18O records, tephrochronological markers 14C AMS radiometric datings) was derived from shallow-shelf drill sites GeoB14403 (54.6 m recovery) GeoB14414 (27.5 m), collected both gravity drilled MeBo cores 193 m 146 m water depth, respectively. The recovered intervals record Marine Isotope Stages Substages (MIS) MIS 5 to 1, thus comprising major stratigraphic parts progradational deposits that form last 100-ka depositional sequence. Calibration shelf units borehole stratigraphies indicates impact higher-frequency (20-ka) sea level cycles punctuating this cycle. This becomes most evident alternation thick interstadial highstand (HST) wedges thinner glacial forced-regression (FSST) mirroring seaward shifts coastal progradation. Albeit their relatively short-lived phase, these subordinate HST bulk Two mechanisms are proposed likely account for enhanced sediment accumulation ratios (SAR) up 200 cm/ka during intervals: (1) intensified activity deep intermediate Levantine Intermediate Water (LIW) associated drowning Mediterranean shelves, (2) amplified flux flooded response hyperpycnal plumes generate through extreme precipitation events overall arid conditions. Equally, latter mechanism is thought be origin undulated features resolved acoustic Interstadials, which bear a striking resemblance modern equivalents forming late-Holocene prodeltas other settings.