The study integrated lithofacies analysis and measurement of total organic carbon "TOC," porosity, and mechanical properties to evaluate the main factors controlling rock strength and elastic properties of three carbonate mudrocks units within the Jurassic succession of Central Saudi Arabia. Textural and microstructural analyses revealed that the former two units (Hanifa Formation Hawtah Member and Tuwaiq Formation) have five lithofacies interpreted as a lower shoreface intra-shelf basin deposition, respectively. Two mudrock lithofacies within the Upper Marrat Formation were recognized, both deposited under peritidal low ramp setting. Weak to moderate correlations between mechanical properties and porosity in all studied formations were observed; coefficient of determination R² values range between 0. 1 and 0.7. Tensile strength has the strongest correlation with porosity and mineral composition. Hard phase mineral (quartz, feldspar, and pyrite) abundance has a more robust correlation with elastic moduli compared to the other minerals. Relatively higher R² values were observed for the correlations between rock strength and clay + TOC content in Tuwaiq and Hanifa compared with Marrat mudrocks. Marrat and Tuwaiq mudrocks lithofacies have a stronger correlation between particle size and unconfined compressive strength, whereas particle size is weakly correlated with elastic moduli. Sedimentary layering and associated anisotropy significantly control these correlations. Deep lower shoreface deposits of Hanifa mudrock are mechanically stiffer than intra-shelf basin outer ramp deposits of Tuwaiq mudrock lithofacies. Peritidal Upper Marrat mudrock lithofacies have slightly higher stiffness than Tuwaiq mudrock and lower stiffness than Hanifa mudrock. The results are useful to predict the rock brittleness of these Jurassic intervals and their worldwide equivalent.

该研究综合了岩相分析和总有机碳“ TOC”，孔隙度和力学性能的测量，以评估控制中沙特阿拉伯侏罗纪演替过程中三个碳酸盐泥岩单元岩石强度和弹性特性的主要因素。结构和微观结构分析表明，前两个单元（Hanifa组Hawtah成员和Tuwaiq组）分别具有5个岩相，分别解释为下岸面陆架内盆地沉积。在上马拉特组中发现了两个泥岩岩相，都沉积在蠕变低坡道环境下。在所有研究的地层中都观察到了力学性能与孔隙度之间的弱到中等相关性；测定系数R ²值范围介于0. 1和0.7之间。拉伸强度与孔隙率和矿物成分具有最强的相关性。与其他矿物相比，硬相矿物（石英，长石和黄铁矿）的丰度与弹性模量具有更强的相关性。R ²相对较高与马拉特泥岩相比，在图瓦伊克和哈尼法，观察到了岩石强度与粘土+ TOC含量之间的相关性数值。Marrat和Tuwaiq泥岩岩相在粒径与无侧限抗压强度之间具有更强的相关性，而粒径与弹性模量之间的相关性较弱。沉积层和相关的各向异性显着控制了这些相关性。哈尼法泥岩的深层下部岸面沉积物比图瓦格泥岩岩相的架内盆地外斜坡沉积物在机械上更坚硬。围岩上马拉特泥岩岩相的硬度略高于图瓦伊克泥岩，而硬度却低于哈尼法泥岩。这些结果有助于预测这些侏罗纪层段的岩石脆性及其全球等效性。