2 research outputs found
Quantifying episodic erosion and transient storage on the western margin of the Tibetan Plateau, upper Indus River
Transient storage and erosion of valley-fills, or sediment buffering, is a fundamental but poorly quantified process that may significantly bias fluvial sediment budgets and marine archives used for paleoclimatic and tectonic reconstructions. Prolific sediment buffering is now recognized to occur within the mountainous upper Indus River and is quantified here for the first time using OSL dating, petrography, detrital zircon U-Pb geochronology, and morphometric analysis to define the timing, provenance, and volumes of prominent valley-fills. This study finds that climatically-modulated sediment buffering occurs over 103–104 yr timescales and results in biases in sediment compositions and volumes. Increased sediment storage coincides with strong phases of Summer Monsoon and Winter Westerlies precipitation over the Late Pleistocene (32–25 ka) and mid-Holocene (~8–6 ka), followed by incision and erosion with monsoon weakening. Glacial erosion and periglacial frost-cracking drive sediment production and monsoonal precipitation mediates sediment evacuation, in contrast to the arid Transhimalaya and monsoonal frontal Himalaya. Plateau interior basins, although volumetrically large, lack transport capacity and are consequently isolated from the modern Indus River drainage. Marginal plateau basins that both efficiently produce and evacuate sediment may regulate the overall compositions and volumes of exported sediment from the Himalayan rain shadow
Jebel Moya (Sudan): new dates from a mortuary complex at the southern Meroitic frontier
This paper proposes a new chronology for the burial complex at Jebel Moya, south-central Sudan. It reassesses the body of evidence from Sir Henry Wellcome's original 1911–1914 excavations in order to place the site within a firm chronological framework by: (a) applying an attribute-based approach to discern discrete pottery assemblages; and (b) applying initial OSL dates to facilitate the reliable dating of this site for the first time. Jebel Moya is re-interpreted as a burial complex situated on the southern periphery of the late Meroitic state, and its potential to serve as a chronological and cultural reference point for future studies in south-central and southern Sudan is outlined