Abstract: The calcium silicates (spurrite, tilleyite), which generally develop under high temperature and low pressure conditions, are principally associated with intrusive bodies of basic composition.This study shows that the spurrite-merwinite facies (the observed mineral assemblages) in this area may occur at thetemperature and pressure conditions of the hornblende hornfels"  at the beginning of the "proxerie hornfels" facies.These calcium silicates may form at the granitic intrusion contact temperatures at about 600°-700°C.