Abstract The Salt and Verde rivers, Sonoran Desert, USA, integrated multiple endorheic extensional basins near the start of the Quaternary. Integration began via spillover on both rivers. Spillover resulted in headward erosion in upstream basins, leading to basin-wide incision and excavation of large volumes of sediment transported into downstream basins. As a result, the Verde River aggraded to what is now the highest terrace in the lower Verde River valley (LVRV), the Lousley Hills terrace. Evidence suggests deposition of the Lousley Hills terrace fill led to aggradation and backfilling of adjacent pediments. Ancestral Salt River Deposits (ASRD) of the combined Salt and Verde rivers deposited an extensive alluvial fan in the Higley Basin, raising local base level for over 2 million years. Eventually, this led to aggradational piracy of the Salt River (~0.46 Ma) that integrated the Higley and Luke basins. Consequently, this shortened and steepened the Salt River, resulting in ~30 m of aggradation downstream and headward incision upstream. Headward incision abandoned the ASRD and created the Sawik stream terrace. Piedmont pediment and alluvial fan systems that were formerly adjusted to the ASRD incised in response. Since abandonment, the ASRD floodplain has accumulated a sheet of silt and fine sand from aeolian and local fluvial processes. Sedimentary, metamorphic, and granitic pediments that developed in slowly aggrading endorheic basins display evidence of response to base-level adjustments resulting from drainage integration processes. Classic ballena landforms (eroding alluvial fans) began to form in the LVRV only after drainage integration — providing the first known maximum age for the ballena form. Drainage integration of the Salt and Verde rivers clearly demonstrates the impact of base-level fluctuations on basin-scale geomorphology. However, integration led to very different geomorphic responses in different extensional basins, revealing the difficulty of a one-size-fits-all conceptual model of geomorphic response drainage integration.

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流域整合对流域地貌和地貌演化的影响：美国索诺兰沙漠盐河和佛得河沿岸的案例研究

摘要 美国索诺兰沙漠的盐河和佛得河在第四纪开始附近整合了多个内陆伸展盆地。整合始于两条河流的溢出。溢出导致上游盆地的上游侵蚀，导致整个盆地的切割和挖掘，大量沉积物被输送到下游盆地。结果，佛得河升级为现在佛得河下游河谷 (LVRV) 中最高的阶地，即 Lousley Hills 阶地。有证据表明，Lousley Hills 阶地填料的沉积导致了相邻山墙的积聚和回填。盐河和佛得河合流的祖先盐河沉积物 (ASRD) 在希格利盆地沉积了一个广泛的冲积扇，使当地的基准面升高了超过 200 万年。最终，这导致了将希格利和卢克盆地整合在一起的盐河 (~0.46 Ma) 的加剧海盗行为。因此，这使盐河变短和变陡，导致下游约 30 m 的积聚和上游的上游切口。前向切口放弃了 ASRD 并创建了 Sawik 溪流平台。以前根据 ASRD 进行调整的 Piedmont 山墙和冲积扇系统作为响应被切开。自废弃以来，ASRD 泛滥平原积聚了一层来自风积和当地河流过程的淤泥和细沙。在缓慢加积的内陆盆地中发育的沉积、变质和花岗岩山冲显示出对排水整合过程导致的基层调整的响应的证据。经典的芭蕾舞地形（侵蚀冲积扇）只有在排水整合后才开始在 LVRV 中形成——为芭蕾舞形态提供了第一个已知的最大年龄。Salt 和 Verde 河的排水整合清楚地表明了基线波动对流域尺度地貌的影响。然而，整合导致不同伸展盆地的地貌响应非常不同，揭示了地貌响应排水整合的一刀切概念模型的困难。