Chloritic Phyllite

These phyllite specimens are from a roadcut about a kilometer east of Tyson, Vermont. The rock is a pelitic phyllite of the Pinney Hollow Formation, in the Camels Hump Group, and has recently been determined to be of Late Proterozoic age, about 570 million years old. These rocks appear to be the more strongly metamorphosed counterpart to the basal slates of the Taconic klippe farther east. They are described as silvery-green chlorite-quartz-sericite phyllite.