Documenting the spatio-temporal progression of deformation within fold-thrust belts is critical for understanding orogen dynamics. In the North American Cordillera, the geometry, magnitude, and timing of contractional deformation across a broad region of Nevada known as the “Sevier hinterland” has been difficult to characterize due to minimal exposures of syn-contractional sedimentary rocks and overprinting of Cenozoic extension. To address this, we present geologic mapping and U-Pb zircon geochronology from three exposures of the Cretaceous Newark Canyon Formation (NCF) in central Nevada. In the Cortez Mountains, NCF deposition between ∼119 and 110 Ma is hypothesized to be related to generation of relief by thrusting/folding to the west. In the Fish Creek Range, NCF deposition between ∼130 and 100 Ma was related to motion on an east-vergent thrust fault. In the Pancake Range, NCF deposition is bracketed between ∼129 and 66 Ma and post-dated east-vergent folding. We incorporate these timing constraints into a compilation of deformation timing in the Sevier hinterland. Late Jurassic (∼165 and 155 Ma) shortening, which is largely post-dated shortening in the Luning-Fencemaker thrust belt to the west and pre-dated initial deformation in the Sevier fold-thrust belt to the east, is interpreted to represent diffuse, low-magnitude deformation that accompanied eastward propagation of the basal Cordilleran décollement. Cretaceous (∼130 and 75 Ma) hinterland shortening, which includes deformation associated with NCF deposition, was contemporaneous with shortening in the Sevier fold-thrust belt. This is interpreted to represent long-duration strain partitioning between the foreland and hinterland during continued coupling above the basal décollement and the progressive westward underthrusting of thick North American lower-middle crust.

中文翻译：

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缩短在美国山脉逆冲推力系统内塞维尔腹地中的作用：内华达中部白垩纪纽瓦克峡谷地层的见解

记录褶皱冲断带内变形的时空变化过程对于了解造山带动力学至关重要。在北美山脉，由于同向收缩沉积岩的最小暴露量和新生代伸展带的叠印，难以描述在内华达州广阔区域（称为“塞维尔腹地”）的收缩变形的几何形状，幅度和时机。为了解决这个问题，我们从内华达州中部的白垩纪纽瓦克峡谷地层（NCF）的三次曝光中介绍了地质制图和U-Pb锆石年代学。在科尔特斯山中，假定在约119至110 Ma之间的NCF沉积与通过向西推动/折叠而产生的浮雕有关。在鱼溪山脉，约130至100 Ma的NCF沉积与东向逆冲断层的运动有关。在Pancake山脉中，NCF沉积物介于约129和66 Ma之间，并为后东东褶皱。我们将这些时序约束纳入Sevier腹地变形时序的汇编中。晚侏罗世（〜165和155 Ma）缩短，主要发生在西侧的Luning-Fencemaker逆冲带的后缩短，而东部的塞维尔褶皱-冲断带早于初始变形，被解释为弥散。 ，伴随着基迪勒山脉底é向东传播的低震级变形。白垩纪（〜130和75 Ma）的腹地缩短，包括与NCF沉积有关的变形，与Sevier褶皱冲断带的缩短同时发生。