The sedimentary and tectonic evolution of the Nam Co Basin, Tibetan Plateau, since the Middle Pleistocene – a seismoacoustic study on lake sediments

Abstract

Advancing climate change threatens the supply of water and sediment resources provided by the Tibetan Plateau. This could expose one-fifth of the global population to significant societal, ecological, and economic adversity. Accurate climate models based on data of past climatic changes are, thus, essential to prepare best for the effects of climate change. A promising and yet undeveloped climate archive is Nam Co (Co= Tibetan for Lake).

This doctoral thesis contributes substantially to the sedimentary, climatic, and tectonic understanding of Nam Co. It sets an essential basis for the evaluation of Nam Co's potential as a high-resolution and extensive climate archive and the selection of suitable drill sites for the ICDP drilling campaign 'NamCore'.

In detail, this thesis investigates 1) spatial sedimentary structures, distributional and depositional processes, and lake-level variations of the last 20.5 kyrs, 2) long-term climate-driven lake-level variations throughout the last 700 kyrs, correlated to the shift of the Asian summer monsoon, and 3) the transtensional tectonic setting of Nam Co, resulting in a novel perception of the tectonic extension in southern Tibet since the Middle Pleistocene.

High-resolution hydro-acoustic data, comprising sediment echo sounder (SES) and multichannel reflection seismic (MCS) data, build the basis of the presented studies.