An otherwise inexplicable kink in the chain marks a shift in the movement of the Pacific plate some 47 million years ago , from a northward to a more northwesterly direction , and the kink has been presented in geology texts as an example of how a tectonic plate can shift direction comparatively suddenly .
A `` bend '' or `` V '' in the chain marks a shift in the movement of the Pacific plate some 47 million years ago , from a northward to a more northwesterly direction .