This is the first systematic investigation of two distinctive geomorphological features recorded in the central Luangwa River valley, Zambia. A series of low hills was found to be capped by thin (~1 m) gravel deposits containing stratified Stone Age artefacts. More widespread gravels occur on the margins of the Luangwa River floodplain lacking stratified artefacts. The previously unreported hilltop deposits are interpreted as remnants of a dissected land-surface, and the valley floor gravels as redeposited clasts from c. 20 m of down-cutting. Clast analysis and drainage basin size analysis support a hypothesis of gravel deposition by unconstrained debris flows from the distant Muchinga escarpment, or from an intermediate zone. Excavation of a perched deposit revealed a coarsely stratified Stone Age record indicating periodic emplacement of artefact-bearing gravels over an extended period. Deposition of these perched gravels continued into the Late Pleistocene (~77 ka), based on OSL dating, after which the current dissected landscape formed. We hypothesize further, based on a regional record of landscape instability and core data from Lake Malawi, that fan formation in the valley was linked to periods of extended aridity and reduced vegetation cover followed by episodic erosional events on the return to wetter conditions. We argue that the subsequent dissection of the land-surface is the end state of a sequence of responses to base-level changes and climate change.

这是对赞比亚中部卢安瓜河谷记录的两种独特地貌特征的首次系统调查。发现一系列低矮的山丘上覆盖着含有分层石器时代文物的薄 (~1 m) 砾石沉积物。卢安瓜河泛滥平原边缘分布着更广泛的砾石，缺乏分层的人工制品。先前未报告的山顶沉积物被解释为解剖地表的残余物，谷底砾石是来自 c. 的再沉积碎屑。20 m 的下切。碎屑分析和流域大小分析支持砾石沉积的假设，即来自远处穆欣加悬崖或中间带的不受约束的泥石流。对栖息沉积物的挖掘揭示了一个粗糙分层的石器时代记录，表明在很长一段时间内定期放置含人工制品的砾石。根据 OSL 测年，这些栖息的砾石的沉积持续到晚更新世 (~77 ka)，之后形成了当前的解剖景观。我们进一步假设，基于景观不稳定的区域记录和马拉维湖的核心数据，山谷中扇形的形成与长期干旱和植被覆盖减少有关，随后在恢复湿润条件时发生偶发性侵蚀事件。我们认为，随后的地表解剖是对基础水平变化和气候变化的一系列响应的最终状态。根据 OSL 测年，这些栖息的砾石的沉积持续到晚更新世 (~77 ka)，之后形成了当前的解剖景观。我们进一步假设，基于景观不稳定的区域记录和马拉维湖的核心数据，山谷中扇形的形成与长期干旱和植被覆盖减少有关，随后在恢复湿润条件时发生偶发性侵蚀事件。我们认为，随后的地表解剖是对基础水平变化和气候变化的一系列响应的最终状态。根据 OSL 测年，这些栖息的砾石的沉积持续到晚更新世 (~77 ka)，之后形成了当前的解剖景观。我们进一步假设，基于景观不稳定的区域记录和马拉维湖的核心数据，山谷中扇形的形成与长期干旱和植被覆盖减少有关，随后在恢复湿润条件时发生偶发性侵蚀事件。我们认为，随后的地表解剖是对基础水平变化和气候变化的一系列响应的最终状态。山谷中扇形的形成与长期干旱和植被覆盖减少有关，随后在恢复湿润条件时发生偶发性侵蚀事件。我们认为，随后的地表解剖是对基础水平变化和气候变化的一系列响应的最终状态。山谷中扇形的形成与长期干旱和植被覆盖减少有关，随后在恢复湿润条件时发生偶发性侵蚀事件。我们认为，随后的地表解剖是对基础水平变化和气候变化的一系列响应的最终状态。