Pre-evaporitic Messinian deposits, consisting of a cyclic alternation of diatomites with lime mudstones, and laminated marls, crop out all over the Mediterranean area, representing important archives of deteriorating environmental conditions. The peculiar section of Torrente Vaccarizzo (Sicily) shows several intervals of organic-rich shales, exceptionally rich in lipid biomarkers, interbedded mostly with diatomites, laminites, and lime mudstones. The research is dealing with geochemical analyses on organic rich-shales to characterize the depositional environments and the organic matter source, as well as to investigate the biological archives predating the extreme saline conditions of the Messinian Salinity Crisis. Biomarker composition along with petrographic results reflect a change from oxic/dysoxic to dysoxic/anoxic conditions towards younger strata. Although a minor terrestrial input is displayed by saccharides, angiosperm biomarkers such as amyrins, dicarboxylic acids, and lignin degradation, most of the n-alkanes, isoprenoids, n-alkanoic acids, steroids, hopanes, and tocopherols are produced by marine hypersaline organisms. Kerogen investigation from Rock Eval pyrolysis revealed a moderate-good oil potential and it pointed to a thermally immature organic matter, which is also confirmed by multiple geochemical parameters (e.g. hopane, sterane). Bituminite at this stage of thermal maturity is not prone to hydrocarbon generation. In general, its hydrocarbon generation potential will depend on the degree of bacterial alteration. This work highlights the relevance in using biomarkers to characterize the response of biological communities to deteriorating conditions.

蒸发前的墨西拿沉积物，包括硅藻土与石灰泥岩的循环交替，以及层状泥灰岩，遍布地中海地区，代表了环境条件恶化的重要档案。Torrente Vaccarizzo（西西里岛）的特殊剖面显示了几个富含有机质的页岩层段，特别富含脂质生物标志物，主要与硅藻土、层纹岩和石灰泥岩互层。该研究正在处理富含有机质页岩的地球化学分析，以表征沉积环境和有机质来源，以及调查在墨西拿盐度危机的极端盐碱条件之前的生物档案。生物标志物组成以及岩相结果反映了从有氧/缺氧到缺氧/缺氧条件向年轻地层的变化。尽管糖类、被子植物生物标志物（如香树脂醇、二羧酸和木质素降解）显示了少量陆地输入，但大多数正链烷烃、类异戊二烯、正链烷酸、类固醇、藿烷和生育酚由海洋高盐度生物产生。来自 Rock Eval 热解的干酪根调查揭示了中等良好的石油潜力，它指出了一种热不成熟的有机质，这也得到了多个地球化学参数（例如藿烷、甾烷）的证实。在这个热成熟阶段的烟煤不容易生烃。一般而言，其生烃潜力将取决于细菌蚀变的程度。这项工作强调了使用生物标志物来表征生物群落对恶化条件的反应的相关性。