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Within the last ten years, micro-XRF (µXRF) core scanning has become an important addition to the suite of techniques for investigating lacustrine sediments. Most studies to date have focused on records of detrital material. These have typically used elements such as Si, K, Ca, Ti, Fe, Rb, Sr and Zr as single element profiles or ratios. Inferences are made about changing catchment dynamics such as glacier advance and retreat, variations in run-off and soil erosion, weathering rates and processes and grain-size fluctuations. These can be linked, depending on the context of the individual basin, to factors such as climatic variability, meteorological events, seismic activity, tephra deposition or anthropogenic disturbance such as agriculture or deforestation. Studies of in-lake dynamics focus on elements affected by redox changes (e.g., Fe, Mn) or those which can be produced authigenically either as a result of evaporative concentration or biological processes (e.g., Ca). Here, we review the use of µXRF core scanning on lake sediments and summarise the range of elements and ratios that have been applied as a reference point for users. We consider some of the challenges involved in interpreting elemental data, given the wide variety of internal and external factors that can affect lake sediment composition.

Evidence for climatic change across the North American Monsoon (NAM) and adjacent areas is reviewed, drawing on continental and marine records and the application of climate models.Patterns of change at 12,000, 9000, 6000 and 4000 cal yr BP are presented to capture the nature of change from the Younger Dryas (YD) and through the mid-Holocene. At the YD, conditions were cooler overall, wetter in the north and drier in the south, while moving into the Holocene

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