COMPARISON OF CLAST AND MATRIX DISPERSAL IN TILL - CANTERBURY AREA, NEW-BRUNSWICK

Matrix granulometric and geochemical components were compared with cla st lithology for 247 samples of basal till, collected on a 2 km2 grid from the Canterbury area in south-central New Brunswick. Plots of comp onent concentrations outlined dispersal patterns elongated southeastwa rd and southward, paralleling the last directions of glacial flow. A c omparison of these data indicated that dispersal pattern size was infl uenced by sample spacing and elevation of source during glacial incorp oration. At a given sample grid, clast lithologies formed relatively l arger and more recognizable dispersal patterns and thus better explora tion targets. Geochemical dispersal patterns were localized and rarely exceeded 6 km in length. Element anomalies could be traced to known m ineral occurrences, but for most elements dispersal patterns were less than 4 km long and defined by one to three sample sites. Clast disper sal patterns could be traced up to 12 km down-ice of source units. Til l components were incorporated locally and reflected short transport d istances. Till matrix was homogeneously mixed and deposited by a singl e glacier as it flowed south and southeastward across the area.