The frontal Zagros fold belt in the Fars area of Iran is generally considered to be detached on the Hormuz salt. Shortening rates and the proportion of thick-skinned deformation are debated and published balanced sections show large differences in style and amount of deformation. We believe that the main uncertainties are related to stratigraphic thickness variations, the degree of thick-skinned deformation and/or the flexural response of the crust. We analysed the stratigraphic thickness ranges interpreted from seismic data and conclude that the interpretational uncertainties, combined with the uncalibrated interval velocities of the largely undrilled Paleozoic strata, yield a wide range of outcomes for the total Phanerozoic thickness (9.5–16.5 km). With an area balancing approach, we show that geological surface cross sections could be matched by various structural subsurface scenarios, including pure thin-skinned deformation with flexure and/or thick-skinned deformation. Given the input uncertainties, we discuss the merits and shortcomings of our balanced sections and propose a geological model including a subtle control on the deformation style by the inherited pre-salt basin morphology. Given the uncertainties, we conclude that the contribution of thick-skinned deformation to the structural evolution remains indefinite and published shortening values may be much more unconstrained than typically specified.

伊朗法尔斯地区正面的扎格罗斯褶皱带一般被认为是在霍尔木兹盐上分离的。缩短率和厚皮变形的比例存在争议，已发表的平衡部分显示在样式和变形量上存在很大差异。我们认为主要的不确定性与地层厚度变化、厚皮变形程度和/或地壳的弯曲响应有关。我们分析了从地震数据解释的地层厚度范围，并得出结论，解释的不确定性，加上大部分未钻孔的古生界地层的未校准层段速度，产生了显生宙总厚度（9.5-16.5 km）的广泛结果。通过区域平衡方法，我们表明，地质表面横截面可以与各种地下结构情景相匹配，包括具有弯曲和/或厚皮变形的纯薄皮变形。考虑到输入的不确定性，我们讨论了平衡剖面的优缺点，并提出了一个地质模型，包括通过继承的盐下盆地形态对变形方式进行微妙控制。鉴于不确定性，我们得出结论，厚皮变形对结构演化的贡献仍然不确定，并且公布的缩短值可能比通常指定的更不受约束。我们讨论了平衡剖面的优缺点，并提出了一个地质模型，包括通过继承的盐下盆地形态对变形方式进行细微控制。鉴于不确定性，我们得出结论，厚皮变形对结构演化的贡献仍然不确定，并且公布的缩短值可能比通常指定的更不受约束。我们讨论了平衡剖面的优缺点，并提出了一个地质模型，包括通过继承的盐下盆地形态对变形方式进行细微控制。鉴于不确定性，我们得出结论，厚皮变形对结构演化的贡献仍然不确定，并且公布的缩短值可能比通常指定的更不受约束。