Rodinian collisional and escape tectonics in the Hudson Highlands, New York

A new multidisciplinary research collaboration to study the western Hudson Highlands, New York, has unraveled a complex Rodinian tectonic history that will be illustrated by visiting key locations on this trip. New sensitive high-resolution ion microprobe (SHRIMP) data demonstrates a cryptic suture between a ca. 1.2-1.1 Ga island arc and sedimentary rocks from a deeply incised craton (Amazonia?). The 1.05 Ga collision between these two terranes produced westward-directed fold nappes, granulite facies metamorphism and the dominant subhorizontal gneissic foliation. Tectonic surge granite sheets were emplaced into the nappes. Bimodal (diorite and granite) plutons intruded the area prior to the onset of a steeply SE-dipping 35-kmwide dextral shear system that resulted from tectonic escape. Extensive iron remobilization and mineralization accompanied the shearing and post-kinematic pegmatite plutons mark the end of activity at ca. 980 Ma.