Figure F6. Compositional changes in magmas produced by the Hawaiian hotspot through time. The shaded field shows the range of published 87Sr/86Sr ratios of tholeiitic basalt vs. age and distance along the Hawaiian-Emperor chain. Note that data from Detroit Seamount are significantly less radiogenic than those at younger volcanoes. The circles with crosses connected by the thick dotted line show the trend in age difference between seamounts and the underlying ocean crust (from Keller et al., 2000).