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The purpose of this study was to map the distribution of till-covered eskers in the inland of Västerbotten County in northern Sweden. The top layers of big eskers along the valleys of Öre River, Ume River and Vindel River were investigated through shallow digging. Findings were investigated through field assessment and soil analysis and many locations with till-covered eskers have been identified in Västerbotten's inland in this survey. The till covering the eskers has probably been transported only short distances and has its origins in glacifluvial material. The pattern is not consistent and there are areas where till does not cover the eskers. This can be explained trough irregular till deposition or that the till has been washed away or alternatively that the upper layer that is interpreted as glacifluvial material actually is till that has only been transported for very short distances. The findings of till-covered eskers in Västerbotten means that the traditional view of the eskers originating from the last deglaciation (Weichsel 3) may need to be reviewed. Where overlaying till has been found on top of eskers it means that the eskers must have originated in an earlier glaciation than the last. Only one layer of till could be discerned on the eskers in the survey, so an explanation could be that the till formed during Weichsel 3 and that the eskers formed earlier by the deglaciation of Weichsel 2, but dating the layers in till-covered eskers is difficult. No transition zone between till-covered to not till-covered eskers was found in this study.

The aim of the study was to assess the possibilities in using ground-penetrating radar to identify small-scale stratigraphy in the upper 1 m of a soil profile and to statistically identify differences in the stratigraphic units discovered using the GPR unit. The study area is ca 15 km southwest of Lycksele near a gravel pit on the banks of Örån. It was located on top of a large (>5 m thick) glacifluvial deposit of indeterminate age overlayed by till from the latest deglaciation. The data sampled included 22 radargrams depicting a total length of >1000 m as well as soil samples from three stratigraphic units from three different trenches (9 samples in total). Visual analysis of the stratigraphy took place via trenches as well as by studying the radar images. The radar images show that three stratigraphic units can be identified clearly (ablation till, S1, a transitional layer of mixed till and glacifluvium, S2, and the underlying glacifluvium, S3) but that the border between the two lower units can be opaque at times. Field observations showed this to be due to the genesis of the topmost unit, the ablation till. Observations in the field also showed relict podsolization in a kettle in the northern part of the study area. Grain-size comparison of the three stratigraphic units identified was performed via sieving. Calculations of the weight percentage were then used for statistical analysis to identify any differences between the strata. Results show that there are differences regarding fine material (ø <0.074 mm, p=0.038), gravel (ø > 2 mm, p<0.0001) and sand (p=0.027) within these three stratigraphic units.