Pliocene–Quaternary fluvial and aeolian records in the Souss Basin, southwest Morocco: A geomorphological model
Pliocene–Quaternary fluvial and aeolian records in the Souss Basin, southwest Morocco: A geomorphological model
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摩洛哥西南部苏斯盆地的上新世-第四纪河流和风积记录：地貌模型
DOI：
10.1016/j.gloplacha.2009.03.002
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发表时间：
2009
影响因子：
3.9
通讯作者：
D. Bridgland
中科院分区：
文献类型：
--
作者：
A. A. Hssaine;D. Bridgland
摩洛哥西南部的苏斯盆地被上新世-第四纪河流、河湖和风成沉积物所充填，代表了古水文、古气候和地壳变形影响的优秀档案。一般来说，这些沉积物表明河流为主的冲积系统，受气候波动（湿度/干旱）的影响。湖泊在上新世-更新世过渡期在盆地内发育，并持续到早更新世。在这一早期阶段，河流系统上游粗颗粒沉积物占主导地位，存在大型湖泊，盆地中心沉积物厚度相当大，表明条件相对潮湿。周围山脉的隆起为皮埃蒙特的形成提供了大量的粗颗粒物质，这些物质在低地边缘堆积。在中更新世气候恶化的同时，河流的形态也逐渐变得不规则和紊乱。这些趋势在晚更新世很明显，在全新世中期之后变得更加明显，风成活动成为主要的沉积剂。上游和下游沉积状况之间的差异变得明显：粗粒沉积物是干河集水区上游的特征，而细粒沉积物则在下游占主导地位。在整个上新世和第四纪的沉积间断的特点是古土壤层间的沉积序列，表明交替植被（稳定）和无植被（不稳定/活跃）阶段（生物和'rhexistasy'）。
The Souss Basin in SW Morocco is filled by Pliocene–Quaternary fluvial, fluvio-lacustrine and aeolian sediments, representing an excellent archive of palaeohydrology, palaeoclimate and the effects of crustal deformation. In general these sediments indicate stream-dominated alluvial systems, influenced by fluctuations in climate (humidity/aridity). Lakes developed within the basin around the Pliocene–Pleistocene transition and persisted into the Early Pleistocene. During this early period, relatively humid conditions are indicated by the dominance of coarse-grained sedimentation in the upper reaches of fluvial systems, the existence of large lakes and the considerable sediment thicknesses in the centre of the basin. Uplift of the surrounding mountain ranges contributed to piedmont formation by providing large amounts of coarse-grained material that accumulated at the lowland margin. Climatic deterioration in the Middle Pleistocene was accompanied by progressively more irregular and disrupted fluvial regimes. These trends were evident in the Late Pleistocene and became clearer after the mid-Holocene, with aeolian activity becoming the dominant sedimentary agent. Differences between upstream and downstream depositional regimes became marked: while coarse-grained sedimentation has characterized the upper reaches of wadi catchments, fine-grained sedimentation has prevailed downstream. Hiatuses in sedimentation throughout the Pliocene and Quaternary are marked by palaeosol horizons interbedded within the sedimentary sequences, indicating alternate vegetated (stable) and unvegetated (unstable/active) phases (biostasy and ‘rhexistasy’).