Apatite (U‐Th)/He (AHe) thermochronometric results are integrated with geologic cross sections, structural relationships, and stratigraphic data to reconstruct the growth of the NW Zagros orogenic belt in the Kurdistan region of Iraq. Prolonged exhumation is documented across the belt with deformation advances and retreats from ~14 Ma onward. After in‐sequence propagation of deformation during middle to late Miocene times, preserved growth strata and AHe data show a deformation retreat by latest Miocene time (~5 Ma). In the NW Zagros, the Phanerozoic succession contains two principal décollements in Lower Triassic and middle Miocene units. The Triassic strata are interpreted as the main décollement for a thin‐skinned system that was dominant during most of the Cenozoic. By ~8–5 Ma, the fold‐thrust belt shifted to basement‐involved deformation in association with growth of the mountain front flexure and reactivation of frontal structures. The shift from thin‐skinned to a hybrid thin‐ and thick‐skinned mode of shortening may reflect variations in the mechanical behavior of the upper crust and the presence of inherited basement discontinuities. On the basis of two NE‐SW balanced cross sections spanning the NW Zagros, the estimated total minimum horizontal shortening is ~18.2 km (6%) in the central and ~16 km (7%) in the southern sectors of the Kurdistan region of Iraq. These findings suggest that the evolution of the NW Zagros orogenic belt was likely driven by the mechanical stratigraphy of the sedimentary cover, inherited basement discontinuities, and the dynamic and thermomechanical effects of potential slab breakoff and lithospheric mantle delamination events.

中文翻译：

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伊拉克库尔德斯坦地区西北Zagros褶皱-冲断带的中新世晚期变形运动学：磷灰石（U-Th）/ He测温法和平衡截面的约束

磷灰石（U-Th）/ He（AHe）的热计时结果与地质剖面，结构关系和地层数据相结合，以重建伊拉克库尔德斯坦地区西北Zagros造山带的增长。记录了整个带上的长时间发掘，从〜14 Ma开始有变形前进和后退。在中新世中期到后期按顺序扩展变形之后，保留的生长地层和AHe数据显示到中新世最晚时间（〜5 Ma）后退了变形。在西北萨格罗斯地区，生代代相包括下三叠统和中新世中期单元的两个主要构造。三叠纪地层被解释为一个薄皮系统的主要构造，该系统在大多数新生代都占主导地位。在大约8-5 Ma之前，褶皱冲断带转变为与基底有关的变形，这与山前弯曲的增长和额叶结构的重新激活有关。从薄皮转变为混合的薄皮和厚皮缩短形式的转变可能反映了上地壳力学行为的变化以及继承的基底不连续性的存在。根据横跨西北Zagros的两个NE-SW平衡横截面，估计库尔德地区的中部总最小水平缩短为〜18.2 km（6％），南部为16 km（7％）。伊拉克。这些发现表明，西北Zagros造山带的演化可能是由沉积覆盖层的机械地层学，继承的基底不连续性，