This work investigated the chemical water–rock interaction of black shale interbedded with limestone along a bedding slip zone and how its deterioration affects the surrounding rock mass in the Xujiaping (XJP) landslide. Many dissolved pits were found on the limestone, and geochemical phenomena were investigated. Rock and water samples from the site were analysed for mineralogy, chemical composition and hydrochemistry. In slip zones, water–rock chemical processes occur in the bedding fractures of interface between black shale and limestone. Thus, a bedding water–rock cyclic reaction experiment was designed with limestone, black shale and black shale interbedded with limestone. Many major elements and heavy elements (Fe, Mn, Si, Zn, Ni, Al, S, Mg, Ca, Na, K, Co and Sr) dissolved out, demonstrating that strong dissolution occurred because of the acidic water during the black shale water–rock interaction. The limestone neutralized the acidic water through black shale oxidation in the interfacial fractures between black shale and limestone, causing deterioration of the slip zone. The acidic water from the fissure network inside the black shale strata migrated along the bedding to the exposed surfaces of cliffs and rock fractures, then evaporated to form secondary mineral phases, including melanterite, rozenite, szomolnokite, and gypsum. The water–rock chemical interaction in the XJP landslide included dissolution, oxidation, dehydration, and neutralization reactions. The accumulation trends and hydrochemical properties at different reaction stages of ions dissolved from the surrounding rock mass in the bedding direction were revealed. The deterioration mechanism was expanded: (i) rock-forming and carbonate minerals were especially prone to dissolution by sulfuric acid from black shale oxidation in the slip zone, and (ii) volume expansion due to the crystallization force of precipitated minerals caused further fracture expansion and deformation. Therefore, geochemical analyses can effectively elucidate the long-term development and nature of slip zones in landslide investigations.

这项工作研究了在层理滑动带上夹有石灰石的黑色页岩的化学水-岩石相互作用及其变质如何影响徐家坪滑坡的围岩。在石灰石上发现了许多溶蚀坑，并研究了地球化学现象。对现场的岩石和水样进行了矿物学，化学成分和水化学分析。在滑移区，黑色页岩和石灰石之间界面的层理裂缝中发生了水岩石化学过程。因此，在石灰岩，黑色页岩和黑色页岩与石灰岩互层的情况下，设计了层理水-岩石循环反应实验。溶出了许多主要元素和重元素（Fe，Mn，Si，Zn，Ni，Al，S，Mg，Ca，Na，K，Co和Sr），表明黑页岩水-岩石相互作用过程中由于酸性水而导致强烈溶解。石灰石通过黑页岩与石灰石之间的界面裂缝中的黑页岩氧化作用中和了酸性水，导致滑移带变质。来自黑色页岩地层裂缝网络的酸性水沿着地层迁移到悬崖和岩石裂缝的裸露表面，然后蒸发形成次生矿物相，包括黑铁矿，菱铁矿，钠蒙脱石和石膏。XJP滑坡中的水-岩石化学相互作用包括溶解，氧化，脱水和中和反应。揭示了在顺层方向上从围岩中溶出的离子在不同反应阶段的积累趋势和水化学性质。恶化机理扩大了：（i）岩性和碳酸盐矿物特别容易在滑移区被黑页岩氧化作用的硫酸溶解，（ii）由于沉淀矿物的结晶力而引起的体积膨胀进一步导致了裂缝扩展。和变形。因此，地球化学分析可以有效地阐明滑坡调查中滑带的长期发展和性质。（ii）由于沉淀矿物的结晶力引起的体积膨胀，引起进一步的裂缝膨胀和变形。因此，地球化学分析可以有效地阐明滑坡调查中滑带的长期发展和性质。（ii）由于沉淀矿物的结晶力引起的体积膨胀，引起进一步的裂缝膨胀和变形。因此，地球化学分析可以有效地阐明滑坡调查中滑带的长期发展和性质。