The salt chimney effect: delay of thermal evolution of deep hydrocarbon source rocks due to high thermal conductivity of evaporites

Half of the topseals to the world's largest oilfields are evaporites. Rock salt has a thermal conductivity two to four times greater than that of other sedimentary rocks found in oil‐ and gas‐bearing basins. Strong heat conduction through evaporites can increase the geothermal gradient above evaporite deposits, resulting in a positive thermal anomaly and above‐average temperature while simultaneously decreasing the geothermal gradient below evaporites, resulting in a negative thermal anomaly. Most Triassic–Jurassic hydrocarbon source rocks in the Kuqa Basin, western China, are overlain by ~1500‐m‐thick Tertiary evaporites with underlying Cretaceous sandstones and mudstones. Directly measured strata temperatures indicate an obvious break in the steepness of the geothermal gradient above and below Paleogene evaporites, with a significantly steeper geothermal gradient above the evaporites. Simulations of the thermal evolution of source rocks based on data collected from well Kela‐2 indicate that if the thickness of evaporites (mainly rock salt and anhydrite rock) in overlying rocks above source rocks increases compared with the thickness of siliciclastic rocks in the overlying rocks, then strata temperatures and vitrinite reflectance in Jurassic source rocks will decrease accordingly. Our thermal simulations based on the thickness and thermal conductivity of evaporites accurately coincide with previous studies based on homogenization temperatures, hydrocarbon–water contact retrospection, and carbon isotope results from natural gases. The gas generation center located in the Kalasu Tectonic Belt today is also sealed in an evaporite‐related structural trap that formed at this time. Therefore, the speculated natural gas generation times not only correlate with the evaporite‐related structural trap formation, but the calculated maturity of deep source rocks below the evaporites also coincides with current gas reserves. And our studies can help to find the deep oils and gases under thick evaporites.     

The People’s Liberation Army Rocket Force: reshaping China’s approach to strategic deterrence

The Chinese People’s Liberation Army (PLA) is in the midst of a sweeping reform programme to significantly transform its organisation, force posture, command and control structures, and internal politics. Among the many important aspects of this effort is the establishment of the PLA Rocket Force (PLARF). Creation of the PLARF solidified China’s missile forces as a critical element of China’s evolving strategic deterrent posture, portends continued significant investment in PLARF modernisation, and points to a more concerted effort to integrate PLARF capabilities into more effective PLA-wide joint operations—all key developments in the fundamental reshaping of China’s approach to strategic deterrence. These developments will affect U.S. strategic and extended deterrence postures, U.S.-China strategic stability, allied conventional force operations, information dominance and security, critical infrastructure, and other key aspects of national security. This study details the organisational, technological, and doctrinal changes afoot for the PLARF, and analyses how—if successful—they affect U.S. and U.S-allied military strategy in the Indo-Pacific region.     

日知先生对中国早期文明史研究的重要贡献

日知先生从世界古典文明史的广阔视野中,用中西古典文明比较研究方法,对中国早期文明史的一些重大问题提出再思考,力图重构中国早期文明史的理论框架,给予中国早期文明史研究很大震动和启示。     

娱乐旅游产品特点浅析

娱乐旅游产品是目前旅游市场主要的产品形式。通过对娱乐旅游产品的构成要素和产品特点进行分析,有利于旅游企业在竞争日趋激烈的市场条件下,把握机遇,壮大自我,扩大产品的市场占有额度。     

南京发现北宋佛顶尊胜陀罗尼经幢

发现于南京市的北宋佛顶尊胜陀罗尼经幢,为了解当时的政治、文化、宗教提供了一份珍贵的实物史料。     

宋初景德镇青白瓷来源及分布研究

景德镇在南唐时期生产青瓷和白瓷,进入宋代后只生产青白瓷。景德镇青白瓷来源可能是繁昌窑青白瓷技术传人或白瓷技术的自然过渡。宋初青白瓷窑址主要分布于南河流域,处于且耕且陶的初级阶段,其分布状况与当时社会政治经济状况有着密切关联。     

仪式、记忆与知识传承——辽东满族"二月二"节俗调查

辽东满族地区的"二月二"节俗包括初一的祭祀准备厦初二当天的祭祀仪式两大部分.时至今日,"二月二"节俗仍然在当地有所传承,其仪式的宗教意识淡化,实用功能凸显,并具有调节农耕周期、传承农耕知识、祈盼农事顺利的地方性功能与意义.正是通过民众的个体与集体记忆的描述,仪式程序及信仰心理的不断强化和巩固,传统农耕知识与技术智慧得以延续传承.     

茂陵石刻表面污染物和可溶盐的分析研究

为了厘清造成茂陵石刻文物劣化的原因和机理,对石刻表面的污染物和析出可溶盐进行了分析研究,以找出石刻文物劣化和污染物、可溶盐之间的关系,为制定科学有效的保护措施提供科学依据。采用X射线衍射仪(XRD)、扫描电镜-能谱仪(SEM-EDS)、傅里叶变换显微红外光谱仪(FTIR)等仪器对采集的茂陵石刻文物表面污染物和可溶盐进行了表征,用离子色谱(IC)分析了可溶盐的离子种类和含量。结果表明,“马踏匈奴”石刻雕像表面污染物的主要成分是CaSO4·2H2O,其形成原因是石材与空气污染物经长期化学反应形成的钙质结壳,或者是地下水中可溶盐的毛细运移造成的;“怪兽吃羊”石刻雕像表面析出的可溶盐有Na2SO4、NaNO3和CaSO4·2H2O,主要是由于地下水中可溶盐从砖石基座迁移到石刻文物本体,随温湿度变化反复结晶溶解所造成。可溶盐会引起石质文物表面酥粉、片状剥落、内部结构破坏等侵蚀,是茂陵石刻文物的主要病害之一。