Sediment dynamics and hydrologic events affecting small lacustrine systems on the southern-central Tibetan Plateau – the example of TT Lake

Abstract

A sedimentological, geochemical, micropaleontological, and palynological study of a lacustrine sediment record from the small TT Lake (southern-central Tibetan Plateau) shows that the background sedimentation was frequently interrupted by event-related deposits. These event-related deposits are interpreted as the result of hydrologic events that are triggered by above-average precipitation events. In total, 11 events were recorded in the TT Lake sequence. Two types can be differentiated: fluvial runoff events caused by precipitation that carried sediment in suspension into the lake and a sediment mass transport caused by torrential precipitation. The hydrologic events appear to be decoupled from long-term climate and environmental variations, but there is evidence that anthropogenic impact, in terms of pastoralism, might have favored the runoff events. The multi-proxy approach proved to be valuable and allowed for a detailed study of sedimentary processes within the lake and its watershed in order to assess their triggering processes and dynamics. The findings show the complexity of these sedimentary processes and their controlling factors, and the study aims to improve their understanding. This study is the first effort to investigate event-related deposits and sedimentary processes on the Tibetan Plateau and its triggering processes and dynamics by utilizing lacustrine sediment records.

Climatically forced moisture supply, sediment flux and pedogenesis in Miocene mudflat deposits of south‐east Kazakhstan, Central Asia

“…Ahlborn et al . () found a strong relationship between precipitation and sediment supply in a small catchment area on the southern‐central Tibetan Plateau. Modelling results have shown that climate variability, in particular precipitation, produce extremely fast responses throughout the catchment–fan system and overprint lower frequency tectonic variations (Allen & Densmore, ).…”

Synchronous pattern of moisture availability on the southern Tibetan Plateau since 17.5 cal. ka BP – the Tangra Yumco lake sediment record

“…) or unsuitable small lacustrine systems, which immediately react to local peculiarities (Ahlborn et al . ). High‐resolution records covering the Lateglacial and the Holocene are urgently needed to further assess the spatial and temporal development of moisture availability on the Tibetan Plateau.…”

Ostracod‐based reconstruction of Late Quaternary lake level changes within the Tangra Yumco lake system (southern Tibetan Plateau)

“…In such a context, ostracods have already been widely used as palaeoenvironmental indicators on the Tibetan Plateau (e.g. Mischke et al ., ; Frenzel et al ., ; Wrozyna et al , , ; Mischke, ; Ahlborn et al ., ; Akita et al ., ; Alivernini et al , ). Palaeoecological applications of ostracod‐based transfer functions have proven to be a useful tool to assess palaeoclimatic conditions (Mischke, ; Viehberg and Mesquita‐Joanes, ).…”