The effect of the introduction of livestock on the erosion of alpine soils: a comparison of five dating techniques applied to sediments of the Australian alpine Blue Lake.

Pb and Cs dating of bulk sediments obtained from the alpine Blue Lake, located in the Snowy Mountains of southeastern Australia, was applied here to date recent lacustrine sediments. In addition, the presence of pollen (a taxon introduced in Australia about 150 years ago) down to a sediment depth of 56 cm in the core is used to obtain a chronology for the upper part of the core. Accelerated Mass Spectrometry radiocarbon dates obtained from organic muds from the same core do not agree with the chronology constructed using the three other dating techniques.

Peak resolution and tailing in alpha-particle spectrometry for environmental samples.

Peak resolution in alpha-particle spectrometry is generally quoted as full-width-at half maximum. However, the extent of tailing of alpha particle peaks into regions of lower energy is often a critical factor for accurate spectral analysis, particularly given the relatively low count rates observed for many environmental samples. In this paper we examine the influence of various factors on peak resolution and tailing for spectra collected using solid-state alpha detectors, in particular chamber gas pressure and source deposit thickness.