Rivers are key elements of the landscape sensitive to changes in the rate of rock uplift. For the case where rock uplift is rapid, rivers experience a drop of their base-level leading to the formation of a knickpoint that propagates through the fluvial network. Such response is expected in extensional settings where rivers incise across the fault scarp direction. The NW portion of the state of Sonora (NW Mexico), belongs to the Basin and Range province where the extensional activity produced the arrangement of mountain ranges with NNW to SSE orientation. The extension started in the Late Oligocene and continued in the Miocene; however, when the landscape responded to the tectonic activity across the river basin remains unknown. The basin morphometry and knickpoint propagation ages are used to explore evidence of the first extensional activity traced back from the modern landscape of the Sonora river basin (SRB). The results of basins morphometric analysis indicate that the landscape steepness is high at the northeastern, central and southern portion of the SRB. Such trend is in agreement with the estimated ages of knickpoint retreat that range from ~19 to ~10 Ma. The results obtained in this study indicate that the landscape of the SRB has been affected by many phases of tectonic events, probably occurred in the Pliocene and Quaternary, and the landscape has not reached the equilibrium.

河流是对岩石隆起速率变化敏感的景观的关键要素。对于岩石快速隆起的情况，河流会经历其基础水平的下降，导致形成通过河流网络传播的折点。在河流切割断层陡峭方向的伸展环境中，预计会出现这种响应。索诺拉州（墨西哥西北部）的西北部分属于盆地和山脉省，在那里伸展活动产生了山脉的排列，山脉具有 NNW 到 SSE 的方向。延伸开始于渐新世晚期，并在中新世继续；然而，景观何时对河流流域的构造活动做出反应仍然未知。盆地形态测量学和临界点传播年龄用于探索从索诺拉河流域 (SRB) 的现代景观追溯到第一次伸展活动的证据。盆地形态测量分析结果表明，SRB 的东北部、中部和南部的景观陡峭度较高。这种趋势与估计的拐点撤退年龄一致，范围从~19 到~10 Ma。本研究结果表明，SRB的景观受到多期构造事件的影响，可能发生在上新世和第四纪，景观尚未达到平衡。SRB 的中部和南部。这种趋势与估计的拐点撤退年龄一致，范围从~19 到~10 Ma。本研究的结果表明，SRB的景观受到多期构造事件的影响，可能发生在上新世和第四纪，景观尚未达到平衡。SRB 的中部和南部。这种趋势与估计的拐点撤退年龄一致，范围从~19 到~10 Ma。本研究结果表明，SRB的景观受到多期构造事件的影响，可能发生在上新世和第四纪，景观尚未达到平衡。