The extensive gypsum karst of Sivas, Turkey is one of the most outstanding examples of bare gypsum karst in the world. It displays a number of remarkable geomorphic features, including: (1) two stepped planation surfaces cut-across folded gypsum developed during an initial phase of slow base level deepening punctuated by periods of stability; (2) unusual deeply entrenched gypsum canyons related to a subsequent phase of rapid fluvial incision and water table lowering; (3) a polygonal karst of superlative quality mainly developed in the upper surface; (4) relict valleys disrupted by sinkholes in the lower erosional surface; (5) a large number of bedrock collapse sinkholes mostly associated with the lower surface; and (6) numerous cover subsidence sinkholes developed in the valley floors. This work analyses the spatial distribution, characteristics and evolution of the sinkholes within the broad Plio-Quaternary geomorphological and paleohydrological evolution of the epigene karst system dominated by autogenic recharge. A cartographic sinkhole inventory has been produced in an area covering 2820 km² with morphometric data and including 295 bedrock collapse sinkholes and 302 cover subsidence sinkholes. The different sinkhole types show a general spatial zonation controlled by the hydrogeological functioning of the different sectors: (1) solution sinkholes (polygonal karst) in the upper recharge area; (2) bedrock collapse sinkholes in the lower denudation surface and close to the base level, where well developed caves are inferred; and (3) cover subsidence sinkholes, with high densities probably associated with areas of preferred groundwater discharge. The morphology of the bedrock collapse sinkholes, varying from small cylindrical holes to large and deep tronco-conical depressions with gentle slopes reflect to geomorphic evolution of these sinkholes that reach exceptionally large hectometre-scale diameters. Their evolution, involving substantial enlargement and deepening, is attributed to the solutional removal as solute load of large volumes of gypsum by downward vadose flow. This type of morphological evolution with significant post-collapse solutional denudation differs from that observed in carbonate rocks characterised by lower solubility and erodibility. The analysis of historical imagery reveals that bedrock collapse sinkholes currently have a very low probability of occurrence and that buried cover subsidence sinkholes are used for urban development creating risk situations.

土耳其锡瓦斯广泛的石膏岩溶是世界上裸露的石膏岩溶最杰出的例子之一。它显示出许多显着的地貌特征，包括：（1）在缓慢的碱液深度加深的初始阶段（由稳定时期打断）形成的两个跨过折叠石膏的阶梯状平整表面；（2）异常深陷的石膏峡谷，与随后的河床快速切割和地下水位降低有关；（3）优质喀斯特多边形岩溶，主要发育于上表面；（4）下部侵蚀面的裂隙破坏了遗迹谷；（5）大量基岩塌陷沉陷坑，大部分与下表面有关；（6）在谷底形成了许多覆盖沉陷坑。这项工作分析了空间分布，表生岩溶系统的广泛的Plio-第四纪地貌和古水文演化范围内的凹陷特征和演化以自生补给为主导。在2820 km的范围内绘制了一个地形下沉清单^2个包括形态学数据，包括295个基岩塌陷塌陷坑和302个塌陷塌陷塌陷坑。不同的沉陷类型显示出受不同扇区的水文地质作用控制的总体空间分区：（1）上补给区的溶液沉陷（多边形喀斯特）；（2）在下部剥蚀面并靠近基层的基岩塌陷塌陷，推测出发育良好的溶洞；（3）覆盖沉降沉陷坑，其密度可能与优选的地下水排放区域有关。基岩的塌陷塌陷形态从小圆柱孔到大而深的圆锥形凹坑，具有缓和的坡度，反映了这些塌陷的地貌演化，达到了非常大的百米尺度直径。他们的演变，由于大量的石膏的溶质负荷是由向下的渗流引起的，因此，溶液的大量膨胀和加深涉及到溶液的去除。这种类型的具有明显的塌陷后溶蚀剥蚀的形态演化与在碳酸盐岩中观察到的不同，其特征是溶解度和易蚀性较低。对历史图像的分析表明，基岩塌陷塌陷坑目前发生的可能性非常低，而掩埋的覆层塌陷塌陷坑被用于城市发展，从而创造了风险状况。这种类型的具有明显的塌陷后溶蚀剥蚀的形态演化与在碳酸盐岩中观察到的不同，其特征是溶解度和易蚀性较低。对历史图像的分析表明，基岩塌陷塌陷目前发生的可能性非常低，而掩埋的覆层塌陷塌陷被用于城市发展，从而创造了风险状况。这种类型的具有明显的塌陷后溶蚀剥蚀的形态演化与在碳酸盐岩中观察到的不同，其特征是溶解度和易蚀性较低。对历史图像的分析表明，基岩塌陷塌陷目前发生的可能性非常低，而掩埋的覆层塌陷塌陷被用于城市发展，从而创造了风险状况。