The Upper Cretaceous Fort Crittenden Formation exposed in the Santa Rita and Huachuca Mountains of southeastern Arizona is a syntectonic deposit that has been associated with Laramide tectonic activity. However, the spatio-temporal relationships among Cretaceous sedimentation, magmatism, basement exhumation, and possible flat slab-related processes in the southern Laramide region remain poorly understood. Age controls for uplift and erosion of local topography and syntectonic deposition in response to deformation remain particularly poor. The Fort Crittenden Formation comprises 800–2500 m of locally derived fluvial to alluvial fan sedimentary rocks and records paleodrainage reorganization in response to active tectonics. Changes in sedimentary facies, provenance, and paleoflow suggest deposition in a tectonically partitioned intraforeland basin. New detrital zircon data constrain the timing of deposition of the Fort Crittenden Formation between ca. 86 Ma and ca. 76 Ma. The lack of depositional age zircons throughout the majority of the Fort Crittenden Formation is consistent with a magmatic lull in the Cordilleran arc between ca. 90 Ma and ca. 76 Ma. The overlying Salero Formation and Late Cretaceous intrusions are expressions of renewed magmatism in southeastern Arizona at ca. 75 Ma. New Lu-Hf data indicate that magmas evolved from contamination of old juvenile crust. When interpreted in conjunction with other regional data sets, our study indicates that the Laramide deformation front migrated eastward into southwestern New Mexico by 75 Ma. Thermal modeling of apatite fission track and (U-Th)/He data from granitic clasts are consistent with Late Cretaceous–Paleocene (ca. 76–55 Ma) heating related to magmatism and cooling and exhumation during the Eocene and Oligocene.

中文翻译：

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Fort Crittenden 地层的年龄和沉积：了解亚利桑那州东南部晚白垩世 Laramide 和新生代构造的窗口

在亚利桑那州东南部的圣丽塔和瓦丘卡山脉出露的上白垩纪 Fort Crittenden 组是一个同构造矿床，与 Laramide 构造活动有关。然而，对拉拉米德南部地区白垩纪沉积、岩浆作用、基底折返和可能的平板相关过程之间的时空关系仍知之甚少。对局部地形的隆起和侵蚀以及对变形作出反应的同构造沉积的年龄控制仍然特别差。Fort Crittenden 地层包含 800-2500 米的局部河流到冲积扇沉积岩，并记录了响应活动构造的古排水重组。沉积相、物源和古流的变化表明沉积在构造划分的前陆盆地内。新的碎屑锆石数据限制了 Fort Crittenden Formation 的沉积时间。86 马和约。76 马。Fort Crittenden 组的大部分地区都缺乏沉积年龄锆石，这与大约 20 年和 90 马和约。76 马。上覆的 Salero 组和晚白垩世侵入体是大约在亚利桑那州东南部重新形成的岩浆作用的表现。75 马。新的 Lu-Hf 数据表明，岩浆是由古老的幼年地壳的污染演化而来的。当与其他区域数据集一起解释时，我们的研究表明 Laramide 变形锋向东迁移到新墨西哥西南部 75 Ma。来自花岗岩碎屑的磷灰石裂变径迹和 (U-Th)/He 数据的热模拟与晚白垩世-古新世（约