Tephrostratigraphy and major element concentrations in glass shards of sediment core MD90-917

A detailed tephrostratigraphy supported by accelerator mass spectrometry (AMS) 14C dating and isotopic and geochemical analyses has been carried out for a deep-sea core collected from the Southern Adriatic Sea, which spans the last 18 14C kyr. Fourteen ash layers have been recognized in the marine core and the origin was determined by comparing their age and geochemistry with tephra detected in terrestrial deposits. The geochemical signatures of marine ash layers indicate a prevailing Campanian and subordinate Etnean and Eolian provenances. Collectively, they are attributed to sources in the Phlegraean Fields (LAM-Lagno Amendolare; LN1/LN2-GM1; C-2/NYT-Neapolitan Yellow Tuff; C-1-Agnano Pomici Principali; AMS/PF-Agnano Monte Spina; AST-Astroni), Somma-Vesuvius (L9-Pomici di Base; L8-Greenish), Mount Etna (Et1-Y1-Biancavilla Ignimbrite), Lipari (E-1-Gabellotto-Fiumebianco) and Palinuro seamount (Pal 1). Some of these eruptions have been detected for the first time in marine cores (Astroni, LAM, L9, L8), and three were detected and dated by marine tephra (LN1, LN2, and Pal 1) providing new more precise stratigraphic markers for the last 18 kyr in the South Adriatic marine record.针对采自亚得里亚海南部（Southern Adriatic Sea）的深海岩芯（deep-sea core），本研究依托加速器质谱法（accelerator mass spectrometry, AMS）碳十四测年（14C dating）、同位素与地球化学分析手段，开展了精细的火山碎屑地层学（tephrostratigraphy）研究，该岩芯的沉积序列覆盖了过去18个14C千年（14C kyr）的时间跨度。该海洋岩芯中共识别出14层火山灰层（ash layers），通过将各层火山灰的年代与地球化学特征与陆相沉积（terrestrial deposits）中发现的火山碎屑（tephra）进行对比，确定了其物源。海洋火山灰层的地球化学特征（geochemical signatures）显示，其主体物源为坎帕尼亚型（Campanian），次要物源为埃特纳型（Etnean）与埃奥利安型（Eolian）火山体系。综合而言，这些火山灰的物源可归为以下几处：弗格雷亚诺火山区（Phlegraean Fields，包含LAM-Lagno Amendolare、LN1/LN2-GM1、C-2/NYT-那不勒斯黄凝灰岩（Neapolitan Yellow Tuff）、C-1-Agnano Pomici Principali、AMS/PF-Agnano Monte Spina、AST-Astroni）、索马-维苏威火山（Somma-Vesuvius，包含L9-Pomici di Base、L8-Greenish）、埃特纳火山（Mount Etna，包含Et1-Y1-比安卡维拉熔结凝灰岩（Biancavilla Ignimbrite））、利帕里岛（Lipari，包含E-1-Gabellotto-Fiumebianco）以及帕利努罗海山（Palinuro seamount，包含Pal 1）。其中部分火山喷发事件（如Astroni、LAM、L9、L8）此前尚未在海洋岩芯中被记录，另有3处事件（LN1、LN2与Pal 1）通过海洋火山灰研究被首次识别并定年，为亚得里亚海南部过去18个14C千年的海洋沉积记录提供了新的、更为精确的地层标志层（stratigraphic markers）。