Angela Turner
School of Geography , Geology and the Environment
Investigating the use of geochemical signatures in glacial tills as a means of identifying ice margins and ice flow direction
Major element analysis was carried out on sediments from 14 different boreholes along the M6 on the Cheshire Plain , with some boreholes providing multiple samples to a maximum depth of 15 m . Three sites in the southwest Pennines were also analysed . The sediments are glacial tills that were deposited during the Last Glacial Maximum about 26500 to 19000 years BP . In total , 54 samples were investigated by Principal Component Analysis ( PCA ) to determine the relationships between the major elements found . The samples were then grouped using Cluster Analysis ( CA ) to explore whether similarities existed between the samples , both vertically within a borehole and spatially across the region . This initial analysis identified boreholes containing homogenous sediments at all depths , and those showing a distinct geochemical difference . It also clearly determined a spatial variation in geochemistry , indicating that this method can be used to identify ice flow direction and source area lithology . In regions where the geomorphological signature of an ice margin in the landscape is weak , such techniques could be vital in understanding the complexity of ground conditions beneath our feet .
Postgraduate Conference 2021 Page 40