Presented are analytical data from lacustrine sediment cores, retrieved from Lake Nam Co (Tibetan Plateau). The sediment core is a composite of one gravity core, taken with a Rumohr-Meischner gravity corer (63 mm diameter) and a piston core, retrieved using an uwitec piston coring system (http://www.uwitec.at; 90 mm diameter). The composite core labelled comprises a total length of 10.378 m. The cores were obtained at N 30.737417, E 090.790333 at a water depth of 93 m on 2008-09-15. The purpose of obtaining this sediment core was to establish a high-resolution record of climate (monsoonal) and environmental change using multiple proxy data. The dataset comprises analytical data based on sedimentological, inorganic geochemical, mineralogical and isotope-geochemical methods. Specifically: sediment water content & density; magnetic susceptibility; particel size data; quantitative inorganic geochemical data (ICP-OES aqua regia and HCL digestions); semi-quantitative XRF elemental data; carbon, nitrogen, sulfur contents; qualitative mineralogical data; bulk sediment stable carbon and oxygen isotope data.

Dried and ground bulk sediment samples were used to collect data on the qualitative mineralogical composition of the deposits. Measurement was carried out with an X-ray powder diffractometer (D8-Discover, Bruker) with a CuΚα X-ray source, 40 kV and 35 mA using an area detector (Gadds 2000). XRD-patterns were recorded over an interval from 3° to 65.5° (2Θ) with a step size of 0.02° within four frames. Frames were combined, integrated and the resulting diffractograms were evaluated qualitatively using the DIFFRACplus.EVA software (Bruker).