A new, high precision U–Pb date from the oldest known rocks in southern Britain
A new, high precision U–Pb date from the oldest known rocks in southern Britain
复制标题
英国南部已知最古老岩石的新高精度 U-Pb 定年法
作者：
D. Schofield;I. Millar;P. Wilby;J. Evans
威尔士边境地区斯坦纳汉特杂岩花岗质花岗岩的高精度U-Pb锆石年龄为710.8±1.5 Ma，与较老的Rb-Sr等时线年龄误差较小。ϵNd值分别为- 0.3和- 1.2，TDM值分别为1394 Ma和1468 Ma，表明岩浆中含有较老的地壳源成分。Nd数据突出了与西阿瓦洛尼亚的差异，后者被广泛认为是晚新元古代北美地区与英国南部的对应，并指出与其他包含更古老的克拉通源物质的近冈瓦南地体更接近的相似性。
Abstract A new high precision U–Pb zircon age of 710.8 ± 1.5 Ma for granophyric granitic rock from the Stanner Hanter Complex of the Welsh Borderland lies just within error of an older Rb–Sr isochron age. ϵNd values of −0.3 and −1.2 combined with TDM of 1394 Ma and 1468 Ma indicate that the magma incorporated an older crustal source component. The Nd data highlight differences with western Avalonia, the widely considered Late Neoproterozoic north American counterpart to southern Britain, and point toward a closer similarity with other Peri-Gondwanan terranes that incorporate older, cratonic source material.