From detailed radiometric and pressure-temperature estimates of the metamorphic history, uplift, and erosion of the Dalradian rocks of the British Isles, we find that 15–25 km of erosion took place mainly in Ordovician time. None of this vast volume of material is apparently present in the Ordovician sedimentary basins that now flank the Dalradian block. We conclude that the Ordovician basins to the south of the Dalradian block are exotic terranes, and we document their emplacement into their present position during Late Ordovician to Early Silurian time (i.e., Taconic) by using evidence mainly from western Ireland.

First Page Preview

First page PDF preview
You do not currently have access to this article.