This paper deals with hornfelses produced by sills and dikes related to the basaltic activity of the Paraná Basin. The studied samples come from the Paulínia, Assistência, Taguaí and Itapeva regions, in the State of São Paulo. In Itapeva, the temperature attained during the recrystallization is estimated at about 740-820º C, corresponding to 500-1000 PH2O- The mineralogical paragenesis of the remaing group of hornfelses provides informations only about the minimum temperatures of recrystallization. From chemical and mineralojpcal analyses, some inferences were made about the nature of the parent rocks, particularly in the Paulínia occurrence. All the studied hornfelses have small contact aureoles, consisting of fine-grained rocks which show no grain size decrease with increasing distance from the contact. These features are analysed and discussed.
