The combination of detrital low-temperature thermochronology with previous U–Pb geochronology, petrological and sedimentological analyses, has proven to be a valuable approach to constrain the provenance of non-marine Lower to Upper Cretaceous synorogenic deposits in the northern Neuquén Basin. This work focuses on the study of the Diamante Formation, a fluvial succession that represents the first synorogenic products of the Andean foreland basin at 34–35°S. The results indicate that the deposition of the Diamante Formation occurred simultaneously with the existence of an active western volcanic arc during the onset of the foreland basin. The facies associations evidence the transition between the backarc and the foreland basin stages as well as the inception of fluvial sedimentation in the foredeep. Petrographic analyses, together with changes in the paleocurrents and the record of limestone clasts suggest a regional detrital source shift. Apatite fission-track analyses (AFT) of a sample collected from the lower part of the Diamante Formation indicate an Albian central cooling age. This sample also evidences a remarkable presence of angular apatite and zircon crystals with subordinated rounded and subangular grains. Zircon fission-track analyses (ZFT) of a sample from the upper part of the Diamante Formation yield two discrete populations of cooling ages, both reflecting source-cooling during the Late Jurassic (∼161 Ma) and the Permian (∼265 Ma). Finally, a comparison between the AFT and the U–Pb maximum depositional zircon-age reveals a short lag time (ca. 3 ma), likely related to the rapid magmatic cooling of a coeval volcanic source at ∼110 Ma (Albian).

碎屑低温热年代学与先前的 U-Pb 年代学、岩石学和沉积学分析相结合，已被证明是限制内乌肯盆地北部非海相下白垩统至上白垩统同源沉积物来源的一种有价值的方法。这项工作的重点是研究 Diamante 地层，这是一个河流序列，代表了 34-35°S 安第斯前陆盆地的第一个共生产物。结果表明，在前陆盆地形成期间，Diamante组的沉积与活跃的西部火山弧的存在同时发生。相组合证明了弧后和前陆盆地阶段之间的过渡以及前渊河流沉积的开始。岩相分析，连同古洋流的变化和石灰岩碎屑的记录表明区域碎屑源发生了转移。从 Diamante 地层下部收集的样品的磷灰石裂变径迹分析 (AFT) 表明阿尔比安中央冷却时代。该样品还证明了有棱角的磷灰石和锆石晶体的显着存在，具有次要的圆形和亚棱角晶粒。对 Diamante 组上部样品的锆石裂变径迹分析 (ZFT) 产生了两个离散的冷却年龄群，两者都反映了晚侏罗世（~161 Ma）和二叠纪（~265 Ma）期间的源冷却。最后，AFT 和 U-Pb 最大沉积锆石年龄之间的比较揭示了较短的滞后时间（约 3 毫安），这可能与 110 毫安（阿尔比安）同时期火山源的快速岩浆冷却有关。