The presence of vitrinite in sedimentary rocks of post-Silurian age allows its reflectance to be used to estimate the thermal maturation of organic matter in petroleum systems. Increasing reflectance of vitrinite, which is primarily driven by aromaticity, depends primarily on the time and temperature attributes of its evolutionary pathway. This study evaluated carbonaceous shales proximal to coal measures and coal samples via isothermal hydrous pyrolysis (HP) to compare differences in the maturation pathways of vitrinite. Sample residues were analysed via vitrinite reflectance (VR_o), geochemical screening tests (organic carbon and programmed temperature pyrolysis), and infrared spectroscopy. The study included samples from Indian and North American basins, to observe differences in vitrinite evolution with respect to enclosing mineral matrix, starting degree of aromaticity, organic matter types, stratigraphic age, and depositional environment. The organic content of HP residues shows an intuitive response to the thermal stress of HP, e.g., a general depletion of total organic carbon (TOC) content, pyrolyzate (S2), and hydrogen index with increasing HP temperature. Infrared proxies including C-factor and CH₂/CH₃ generally decrease with increasing thermal maturity indicating loss of O via CO₂ generation and the thermal cracking of aliphatic organic matter. T_max, production index (PI), and VR_o show intuitive increasing values with respect to HP temperature. The least mature sample (0.48 ± 0.05% VR_o) generally experienced the maximum change in these parameters during maturation, whereas the most mature sample (0.99 ± 0.06% VR_o) generally showed the least change. This observation is consistent with higher kinetic barriers to reaction in more aromatic vitrinite which contains higher bond dissociation energies. Devolatilization of vitrinite during HP causes formation of gas evacuation vacuoles and contraction cracks in the vitrinite grains of both coal and carbonaceous shale. Similarities in vitrinite response to HP between coal and carbonaceous shale suggest that thermal evolution of the vitrinite maceral is principally controlled by inherent rate-limiting kinetic parameters related to its molecular structure. Whereas, the stratigraphic age, sedimentary environment, surrounding organic matter, lithology, and catalysis by mineral composition have less effect. To further improve our understanding of vitrinite aromatization and kinetic parameters, future studies of vitrinite reflectance thermal evolution with temperature should include coal and carbonaceous shale from the same stratigraphic section and extant woody tissue from modern vascular plants.

后志留纪沉积岩中镜质体的存在使其反射率可用于估计石油系统中有机物的热成熟。主要由芳香性驱动的镜质体反射率增加主要取决于其进化途径的时间和温度属性。本研究通过等温含水热解 (HP) 评估了靠近煤系和煤样的碳质页岩，以比较镜质体成熟途径的差异。通过镜质体反射（VR _o)、地球化学筛选测试（有机碳和程序升温热解）和红外光谱。该研究包括来自印度和北美盆地的样品，以观察镜质体演化在封闭矿物基质、芳香性起始程度、有机质类型、地层年龄和沉积环境方面的差异。HP 残留物的有机物含量显示出对 HP 热应力的直观响应，例如，随着 HP 温度的升高，总有机碳 (TOC) 含量、热解物 (S2) 和氢指数普遍下降。包括 C 因子和 CH ₂ /CH ₃在内的红外代理通常随着热成熟度的增加而降低，表明 O 通过 CO _2损失脂肪族有机物的生成和热裂解。T _max、生产指数 (PI) 和 VR _o显示相对于 HP 温度的直观递增值。最不成熟的样本 (0.48 ± 0.05% VR _o ) 通常在成熟过程中经历这些参数的最大变化，而最成熟的样本 (0.99 ± 0.06% VR _{o )}) 通常表现出最小的变化。这一观察结果与在含有更高键解离能的更多芳族镜质体中反应的更高动力学障碍一致。HP过程中镜质体的脱挥发分导致煤和碳质页岩的镜质体颗粒中形成排气空泡和收缩裂缝。煤和碳质页岩之间对 HP 的镜质体响应的相似性表明，镜质体的热演化主要受与其分子结构相关的固有限速动力学参数控制。而地层年龄、沉积环境、周围有机质、岩性和矿物成分的催化作用影响较小。为了进一步提高我们对镜质体芳构化和动力学参数的理解，