Climate variability in the northern Mediterranean across the onset of the Messinian salinity crisis: insights from inorganic and organic geochemical proxies

This data set was used to trace the climate and hydrologic variability in the northern Mediterranean in the late Miocene, from about 6.07 to 5.92 Ma. This time interval encompasses the onset (5.97 Ma) of the Messinian salinity crisis (MSC), an event which lead to prominent environmental changes in the Mediterranean area. The Messinian organic-rich shales and marls are cropping out in the Govone section (44°48′08″N; 8°07′34″E, NW Italy). The analyses included X-ray fluorescence (XRF), lipid biomarkers and their compound specific carbon and hydrogen stable isotopes. XRF was done to assess the distribution of major (Al, Si, Ti) and trace (Zr) elements. Si/Al, Ti/Al and Zr/Al ratios were used to qualitatively assess the influence of aeolian inputs. Lipid biomarker analyses targeted long-chain n-alkanes, derived from leaf waxes of land plants, which were identified and quantified, allowing to trace terrestrial organic matter input in the study area. We calculated the Carbon Preference Index (Bryan and Evans, 1961) based on the concentration of the n-C24 to n-C34 alkanes to trace the level of degradation/contamination of the terrestrial organic matter. Finally, carbon (δ13C) and hydrogen (δ2H) stable isotopes of the n-C31 and n-C33 alkanes were determined. δ13C values allowed to reconstruct variations in vegetation (C3 vs C4 plants), while δ2H values helped in reconstructing the hydrological cycle at the onset of the Messinian salinity crisis in the northern Mediterranean. […]本数据集旨在追溯地中海北部地区晚中新世（约6.07至5.92 Ma）的气候与水文变化特征。该时段涵盖了墨西拿盐度危机（Messinian salinity crisis, MSC）的起始节点（5.97 Ma），这一事件曾引发地中海区域显著的环境变迁。晚中新世富有机质页岩与泥灰岩在意大利西北部的戈沃内剖面（44°48′08″N；8°07′34″E）出露。本次分析涵盖X射线荧光光谱（X-ray fluorescence, XRF）检测、脂质生物标志物分析，以及针对这些标志物的化合物特异性碳、氢稳定同位素分析。通过XRF检测，可评估常量元素（Al、Si、Ti）与微量元素（Zr）的分布特征，利用Si/Al、Ti/Al及Zr/Al比值可定性表征风成输入的影响程度。脂质生物标志物分析以陆生植物叶蜡来源的长链正构烷烃为研究对象，通过对其定性与定量检测，实现对研究区域内陆源有机质输入情况的追溯。本研究基于n-C24至n-C34正构烷烃的浓度，计算得到碳优势指数（Carbon Preference Index, Bryan and Evans, 1961），以此表征陆源有机质的降解/污染程度。最后，对n-C31与n-C33正构烷烃的碳（δ¹³C）、氢（δ²H）稳定同位素进行了测定。δ¹³C值可用于重建植被组分变化（C3植物与C4植物的相对占比），而δ²H值则有助于还原地中海北部地区墨西拿盐度危机起始阶段的水文循环过程。[…]