Gaiteiros-1 borehole, located in the central Lusitanian Basin (Portugal), drilled a continuous Jurassic (Hettangian to Kimmeridgian) sedimentary sequence. Forty-one samples were selected for this study to characterize the dispersed organic matter and its vertical variation along Gaiteiros-1 borehole and to evaluate the environmental changes based on palynofacies and bulk geochemistry analyses.

Gaiteiros-1 borehole lithological sequence is characterized by a low organic carbon content, which varies between 0.10 wt% and 0.83 wt%, in Candeeiros carbonates and Lower Jurassic Coimbra Formation, respectively. The insoluble residue content indicate a carbonated character in almost the entire sequence, except for Kimmeridgian samples. The palynofacies analysis evidences the presence of the main groups of kerogen (Phytoclats, Amorphous and Palynomorphs) with a dominance of the amorphous group in the carbonated samples and phytoclasts in Kimmeridgian detritic samples. Different types of amorphous particles were identified, suggesting periods of reworking by bacterial activity and primary bioproductivity in depleted oxygen environments. Despite the dominance of amorphous particles, the kerogen groups vertical variation provides information that reveals changes in the depositional environment. The kerogen assemblage of the Candeeiros facies suggests a stratified water column, with well-oxygenated layers, responsible for high primary productivity periods, which allowed for the development of zooplankton, preserved in the form of zooclasts fragments and foraminiferal test-linings. The contribution of the Palynomorph group is scarce during the Lower-Middle Jurassic but increases in the Upper Jurassic. This modification in the kerogen assemblage reflects changes in the sea level, oxygenation conditions, climate and proximity to the terrestrial source area. The presence of Coleochaete-like freshwater algae was detected for the first time in the Lusitanian Basin, suggesting more restrictive conditions during the Late Oxfordian. During the Kimmeridgian, the amorphous material disappears and phytoclasts, mainly opaque phytoclasts, come to dominate the kerogen assemblage, as a result of terrigenous sediments input, due to the great proximity to the terrestrial source area.

Gaiteiros-1 钻孔位于 Lusitanian 盆地中部（葡萄牙），钻探了一个连续的侏罗纪（Hettangian 到 Kimmeridgian）沉积层序。本研究选择了 41 个样品来表征沿 Gaiteiros-1 钻孔的分散有机质及其垂直变化，并根据孢粉相和大块地球化学分析评估环境变化。

Gaiteiros-1 钻孔岩性层序的特征是有机碳含量低，分别在 Candeeiros 碳酸盐岩和下侏罗纪科英布拉组中，其含量介于 0.10 wt% 和 0.83 wt% 之间。除了 Kimmeridgian 样品外，不溶残留物含量表明几乎整个序列中的碳酸化特征。孢粉相分析证明存在主要的干酪根类群（植酸盐、无定形和孢粉形），其中无定形组在碳酸化样品中占主导地位，而在 Kimmeridgian 碎屑岩样品中以植物碎屑为主。鉴定出不同类型的无定形颗粒，表明在缺氧环境中细菌活动和初级生物生产力的再加工期。尽管无定形颗粒占主导地位，干酪根群的垂直变化提供了揭示沉积环境变化的信息。Candeeiros 相的干酪根组合表明一个分层的水柱，具有良好的充氧层，负责高初级生产力时期，允许浮游动物的发展，以动物碎屑和有孔虫测试衬里的形式保存。Palynomorph 群的贡献在中下侏罗统很少，但在上侏罗统增加。干酪根组合的这种变化反映了海平面、氧化条件、气候和靠近陆地源区的变化。的存在 负责高初级生产力时期，这允许浮游动物的发展，以动物碎屑和有孔虫测试衬里的形式保存。Palynomorph 群的贡献在中下侏罗统很少，但在上侏罗统增加。干酪根组合的这种变化反映了海平面、氧化条件、气候和靠近陆地源区的变化。的存在 负责高初级生产力时期，这允许浮游动物的发展，以动物碎屑和有孔虫测试衬里的形式保存。Palynomorph 群的贡献在中下侏罗统很少，但在上侏罗统增加。干酪根组合的这种变化反映了海平面、氧化条件、气候和靠近陆地源区的变化。的存在 氧条件、气候和与陆地源区的接近程度。的存在 氧条件、气候和与陆地源区的接近程度。的存在在 Lusitanian 盆地首次发现了类似鞘毛类的淡水藻类，表明晚牛津阶的条件更为严格。在 Kimmeridgian 期间，由于陆源沉积物的输入，无定形物质消失，植株碎屑，主要是不透明的植株碎屑，在干酪根组合中占主导地位，因为它与陆地源区非常接近。